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  Земна температура спрямо дълбочина
Публикувано от: mzk - 15-05-2016, 11:19 AM - Форум: Термопомпи / Heat pumps - Без отговори

Температурата в почвата зависи от местоположението, сезона и дълбочината, но следните източници дават обща представа.



Цитат:Източник: http://www.homeintheearth.com/tech_notes...xperiment/

Схема на сензорите. Контролна група (дясно) и засенчена група (ляво). Засенчената група се намира под найлон, който намалява влажността на почвата.
[Изображение: attachment.php?aid=127]

Резултатите:
[Изображение: attachment.php?aid=126]


Цитат:http://www.builditsolar.com/Projects/Coo...atures.htm
[Изображение: attachment.php?aid=128]

Цитат:http://www.engr.uconn.edu/environ/envphy...ng2004.pdf

The thermal conductivity also increases with increasing water content. Soil water improves the thermal contact between the soicontent. Soil water improves the thermal contact between the soil l particles, and replaces air which has 20 times lower thermal particles, and replaces air which has 20 times lower thermal conductivity than water. conductivity than water.


Виж още:
http://www.cleavebooks.co.uk/scol/ccthcony.htm
https://en.wikipedia.org/wiki/Soil_thermal_properties
The main soil thermal properties are:
   Volumetric heat capacity, SI Units: J∙m−3∙K−1
   Thermal conductivity, SI Units: W∙m−1∙K−1
   Thermal diffusivity, SI Units: m2∙s−1



Прикачени файлове Миниатюри
           
Принтирай

  Боклук
Публикувано от: mzk - 15-05-2016, 10:51 AM - Форум: Екология и икономика, енергийна ефективност и ВЕИ - Без отговори

Пълната статия с картинки и видео на адрес: http://binar.bg/42356/bitkata-za-bokluka/

Каква е първата ви асоциация, когато чуете думата „боклук“?
Нещо ненужно, нещо гадно, нещо, което не ме интересува… Но всъщност правилното обработване на боклука може да го превърне и в значим ресурс, да съкрати порочния кръг или да намали до нула отпадъците, ако бъдат изпълнени определени условия.
С Ивайло Хлебаров – експерт по управление на отпадъците, се разходихме в центъра на София и разговаряхме открито за софийския боклук.
От 10 години се опитваме да събираме софийския боклук разделно, защо в крайна сметка не се получава?
Да, наистина, от края на 2005 г., вече над 10 години, откакто е въведено разделното събиране на отпадъци от опаковки в София. Не се получава, защото изначално разделното събиране в София е замислено да пази статуквото, като само изпълнява минималните законови изисквания. То не цели да промени системата така, че здравето на хората и опазването на природата да са приоритет, каквато е една от целите на разделното събиране.
Приоритет за администрацията е най-вече с минимални организационни усилия да се продължава непрозрачното харчене на събраната такса смет от гражданите и бизнеса, като се залага на скъпа, неефикасна, неефективна и също така вредна за здравето на хората и околната среда система за управление на всички битови отпадъци на София.
При такива приоритети целта не е гражданите и бизнеса да разделят, а точно обратното, да продължават да си хвърлят както досега. После някакви магически технологии ще разделят вместо нас, ще генерират пренебрежимо количество мръсна енергия, като останалите отпадъци ще се заравят.
Тази енергия от отпадъци, която е голямата гордост на Столична община, всъщност ще подмени енергията, която се генерира с 10% от природния газ, който ползва Топлофикация. Подменя се едно сравнително чисто гориво с едно доста по-мръсно и енергията ще я плащаме прескъпо, веднъж със здравето си заради още по-замърсения от сега въздух, втори път чрез сметките за парно и топла вода, тъй като тя се изкупува все едно е някакво зелено производство. Тази схема е замислена от над 10 години в София и никакви разумни аргументи не можаха да я променят. Защо? Заради няКОЙ.
Какъв е смисълът от разделното хвърляне на отпадъци? Много хора се отказват, виждайки, че все пак боклукът се събира в един камион…
[Изображение: 11-660x440.jpg]Ивайло Хлебаров от години следи процесите, свързани със обработването на софийския боклук.
Смисълът е в това, че чрез разделното събиране в крайна сметка се допринася за опазване здравето на хората и на околната среда. Може би звучи абстрактно, но я си складирайте всичкия отпадък в банята за известно време или пък го запалете и дишайте дълбоко. Може би ще се сгреете малко от енергията в отпадъка, но след това трудно ще дишате, а след като установите, че огънят не е направил боклука да изчезне, ще се наложи да преместите пепелта я в хола, я в кухнята… Правете това около 25-30 години и… мисля, вече е ясно, че нито да закопаете, нито да изгорите боклука си е решение.
Като го разделяте, давате възможност на ресурсите в него отново да бъдат ресурси като отново влязат в употреба и намалявате нуждата от добиването на нови. Но това, че вие разделяте, не е достатъчно, трябва и да се събере разделно.
Допреди години наистина имаше практика камионите да събират наедно разделно събраните отпадъци. Това сега е рядкост, но ако се случва и забележите това, вместо да се отказвате от разделното събиране, опитайте се да го направите работещо чрез гражданско действие. Снимайте, ако можете, обадете се директно в компанията, която събира разделно във вашия квартал или село, подайте сигнал в общината и поискайте да си свършат работата по контрола, обадете се в „За Земята“. Ако не го правим, в крайна сметка участваме в поддръжката на статуквото.
От друга страна, всяко управление на отпадъците трябва чрез мерките, които прилага, същевременно да образова, да обяснява ползите и вредите, да подпомага – чрез финансови стимули и чрез справедлива такса смет, или информационно – да контролира и премахва нередностите. Това обаче изисква една отворена към хората – да я нарека приобщаваща и компетентно разработена и водена – политика от страна на администрацията и общинския съвет в София. Такава няма и то не само по отношение на отпадъците, а и на много други неща в София.
[Изображение: 21-660x440.jpg]Централна софийска улица. Ивайло се пита къде са кофите за разделно събиране…
Поради това отпадъкът в София се движи основно по стария линеен начин. Добив на суровини, производство, употреба и накрая изхвърляне чрез закопаване в сметище или унищожаване чрез изгаряне. Едни от героите, които променят тази система са клошарите, но отхвърлянето им или по-скоро зачеркването им не само, но най-вече от институциите (министерство, община и част от компаниите, събиращи разделно опаковки) показва, че имаме много труден път да извървим като общество.
Граждани често се оплакват, че в близост до тях липсват кофи за разделно хвърляне на боклука. Какво се прави в такива ситуации?
Липсата на кофи за разделно събиране е продиктувана най-вече от икономически съображения на фирмите, които ги поставят. Това са организациите за оползотворяване на отпадъци от опаковки (ОООО), в които участват почти всички компании в България. Тези организации събират такси от компаниите, които чрез дейността си пускат на пазара различни опаковани стоки, за да може впоследствие една част от тези опаковки да се събере разделно и да влезне отново в кръговрата на ресурсите.
По време на икономическата криза от 2008 г. събраните такси намаляха – те по принцип са неадекватно ниски, което доведе до премахването на повечето контейнери в София. В България има цели общини, в които няма разделно събиране, защото икономически не е изгодно за компаниите и общините са оставени сами на себе си. Това не е проблем сам по себе си. Ако общината реши да впрегне сили, може и сама да се справи, но, както споменах, това изисква доста организационна работа, не толкова експертна или технологично скъпа инфраструктура.
Моделът е сбъркан, тъй като разделното събиране е оставено в ръцете и финансите на компаниите, а отговорността е на кмета. Кметът освен финансови има и куп други съображения, които в крайна сметка трябва да водят до опазване на човешкото здраве и околната среда.
[Изображение: 32-660x440.jpg]След дълго лутане открива трите вида контейнери за разделно изхвърляне на отпадъци.
Какво се прави, когато няма кофи наблизо? Няколко неща могат да се направят: носи се до следващите най-близки; оставят се разделени отпадъците до сивите кофи, за да може клошарите да ги вземат; носите ги на вторични суровини. Може да се организирате заедно със съседи (по вход, етажна собственост) да събирате и предавате на рециклираща фирма някои основни вторични суровини – пластмасовите бутилки, хартия и др., а приходите да използвате за облагородяване на общите съседски пространства (зелени площи, стълбища и др.) – проверете предварително какво да събирате, както и цените и условията с лицензирани фирми или най-близкия пункт за вторични суровини.
Отделно може отново да се обадите на ОООО, да направите репортаж, да пишете до общината, че няма къде да изхвърляте разделно и т.н. Трябва да сме активни и да изискваме институциите да спазват задълженията си, защото макар промяната да започва от нас, без институциите трудно можем да постигнем добри резултати.
Възможно ли е да компостираме боклук и в домашни условия, независимо в какъв вид жилище живеем? Знаеш ли за подобни инициативи от страна на общината и доколко са успешни?
Възможно е. Най-лесно, разбира се, е ако имате къща с двор, но се практикува и в апартаменти и дори офиси. В „За Земята“ има компост с червеи. Но това са лични инициативи, тъй като няма институционална подкрепа за тях. В общината за тези 10 години всичко е на пилотен етап, а трябваше да е масово. Вижте в Италия, Испания, Словения, картината се променя коренно в рамките на 2-4 години. Давам тези държави за пример, защото те доскоро бяха на нашето дередже и имаха да наваксват много спрямо традиционната Западна Европа, но в някои отношения за много кратко време те се представят вече по-добре от Германия или Швеция като отказват да горят отпадъците си и залагат на разделно събиране и на органичните отпадъци.
А в София понеже е пилотно, информацията е предимно достъпна само за пилотите. Сигурен съм, че много малко хора знаят, че Столична община раздава (пилотно) компостери безплатно от 2006 г. насам. Но дори и аз не знам детайлите, прави ли се още, в кои квартали. Информацията за ефекта от този пилотен проект е в някоя черна кутия в общината.
Какви видове съоръжения има за третиране на софийския боклук и доколко ефективни са те?
[Изображение: 41-660x440.jpg]Оказва се, че хората, които най-успешно рециклират, са клошарите на София.
Важно е да се отбележи, че преди да говорим за ефективността на тези съоръжения е необходимо да говорим за целесъобразността им. Защото ако нещо не е добро, то дали е повече ефективно или по-малко не е особено важно. Системата в момента включва депото в местността Садината до гара Яна, две инсталации за биологично третиране на градинските и хранителни отпадъци, като отпадъците, постъпващи в тях, са разделно събрани. Третият компонент е инсталацията за механично-биологично третиране (МБТ) с капацитет 410 000 т/г. Основен продукт на МБТ-то е горивото от отпадъци (РДФ), което представлява изсушени, нарязяни и доразбъркани пластмаси, хартии, гума, кожа и биомаса, но и известно количество опасни отпадъци. Последното съоръжение от системата, което е и най-противоречивото, е инсинераторът или инсталацията за изгаряне на отпадъци, която е одобрена за територията на ТЕЦ София, зад Централна гара.
Инсинераторът ще изгаря РДФ, като ще произвежда известно количество топло- и електро-енергия за успокоение на нечии души. След изгарянето ще има нужда остатъчните опасни отпадъци да се депонират в депо за опасни отпадъци, с каквото София не разполага, или да се изнасят в чужбина, което допълнително оскъпява процеса.
Съвсем накратко системата в София е фокусирана почти изцяло върху обработването на вече смесени битови отпадъци, които след това имат два пътя – депониране и изгаряне. През януари 2016-а Европейската комисия излезе с доклад, оценяващ разделното събиране в ЕС. Една от препоръките е към разделното събиране на опаковки (каквото е в София) да се въведе задължително разделно събиране и на биоотпадъците, хартията и други материали в битовите отпадъци, което обикновено води до по-високи нива на рециклиране. Според доклада разделното събиране в София е едва 4%, което неминуемо води и до ниско рециклиране. Дори съоръженията в София да работят максимално ефективно, то те ще рециклират едва 18.2% от отпадъците, които постъпват в тях, останалото ще се гори и депонира.
Опитът на водещи общини от цял свят показва, че съотношението трябва да е обратното: 80% от отпадъците ни могат да се рециклират или компостират, а за по-малко от 20% днес все още няма решение, освен да се изхвърлят или изгарят, но вторият вариант е най-опасен и нежелателен.
Изгарянето допълнително ще замърси въздуха в София, тъй като природен газ се подменя с по-мръсно гориво. Съоръженията ще струват над половин милиард лева без оперативните разходи и неминуемо ще повишат разходите на гражданите срещу съмнителни ползи, като същевременно не се стимулира рециклирането. Инсталациите за градински и хранителни отпадъци са с малък капацитет спрямо общото количество биоотпадъци в София и работят на под 50% от капацитета си. В крайна сметка разделното събиране стагнира 10 години и ако не се промени организацията му, то няма да се подобри. Системата дългосрочно ще доведе до влошаване на околната среда и здравето на хората при равни други условия.
Как функционират съоръженията за биологично третиране като това в Хан Богров?
[Изображение: 61-660x440.jpg]Готов компост. Краен продукт на съоръжението.
Има два основни начина за преработване на храна и растителни остатъци (т.нар. биоотпадъци). Компостирането е естественото разграждане на органична материя при наличието на кислород, при което се получава почвоподобрител. Анаеробното разграждане на биоотпадъци става в безкислородна среда, при което се получава метан (биогаз) и утайка, която може да се компостира. Основното правило и в двата случая (според практиката и според българското законодателство) е на компостиране и анаеробно разграждане да се подлагат само разделно събрани биоотпадъци, без примеси, които да пречат на процесите и развалят качеството на крайните продукти.
Отпадъците се приемат и преглеждат за нежелани примеси, след което се надробяват и съответно храните се подлагат на анаеробно разграждане, а градинските отпадъци – на компостиране. Произведеният газ може да бъде пречистван и използван за отопление или гориво за превоз, или да бъде превръщан в електроенергия. На Хан Богров правят второто и продават произведения ток на мрежата на субсидирани цени, а през зимата се използва за отопление на администрацията. Към момента инсталациите работят с под 50% натоварване, което ще се повишава много бавно в следващите години. Това се дължи както на трудности в разделното събиране, така и на нуждата голямата МБТ инсталация да получава нужното количество биомаса за производство на РДФ. А трябваше да е обратното, фокусът да се тези инсталации, а не на МБТ-то.
Какво според теб трябва моментално да се случи по отношение на боклука в София?
Най-вече три неща. Да се въведе задължително разделно събиране на органичните отпадъци (градински и хранителни) на цялата територия на София. Така ще се намали смесването и цапането на хартията, пластмасата и другите рециклируеми материали, които по-лесно ще могат да се събират разделно и впоследствие рециклират.
Второ, за да се стимулира системата за разделно събиране, трябва такса смет да се базира на количеството изхвърлен отпадък. Така ще се стимулира намаляването на изхвърлянето на отпадъци – тези, които разделят, реално ще плащат по-малко от останалите.
Третото нещо е, че не трябва да се строи инсталацията за изгаряне на отпадъците. С всеки нов доклад, с всяко ново екологично законодателство става все по-ясно, че горенето е загуба на ресурси (включително на енергия), замърсява и е скъпо.
Какви са опасностите от неправилното съхраняване или третиране на боклука за земята и за нас самите?
[Изображение: 71-660x440.jpg]Зад Ивайло и това разлистило се дръвче бяха изхвърлени строителни отпадъци.
Спомнете си примера от началото с боклука в банята. Иначе съвсем реално, можем да се върнем към 2005 г., когато се затвори сметището в Суходол, София се задръсти с отпадъци, полицията би протестиращите в Суходол, а зам.-кмета Минко Герджиков ни пробута скъпото балиране. След това започна сагата със ”Завода” на Бойко Борисов, договорките с различни общини да приемат балите срещу инвестиции или политически уговорки. В крайна сметка хората около него измислиха настоящата система за София и сагата още не е приключила. Отпадъците водят със себе си не само екологични, но финансови и политически последици. Битките за опазване на околната среда са един вид битки за повече демокрация и участие в решенията за развитието на обществото ни, които пряко ни засягат.
Нека не забравяме, обаче, че битовите отпадъци – тези, които хвърляме в кофата – са около 10% от всички отпадъци, които генерираме. Глобалното производство обаче също следва линейния модел на изкопаване, производство, употреба, изхвърляне, изгаряне, депониране и цялото това производство е съпътствано с отделянето на огромно количество отпадъци, голяма част от които токсични. Не случайно говорим за кръгова икономика, в която отпадъкът се връща в кръговрата на природата и производството. Предизвикателството е огромно и, както е видно, в България е едно от многото, но или се захващаме с тях, или, както има една приказка от близкото минало, да се покрием с белите чаршафи и да се запътим към Орландовци.
Ивайло Хлебаров работи с различни неправителствени организации в областта на околната среда, гражданското участие, пряката демокрация и напоследък устойчивата градска среда. Бил е дългогодишен координатор на програмите „Нулеви отпадъци“ и „Международни финансови институции“ в екологично сдружение „За Земята“/“Приятели на Земята – България“.
В момента е съветник към екипа „Нулеви отпадъци“ на организацията. Бакалавърската си степен получава в Техническия университет (София) – специалност „Системи и управление“. Магистърската му степен е от Университета Лунд в Швеция в областта на околната среда и наука за устойчивостта.

Принтирай

  I2P (Internet Invisible Project)
Публикувано от: mzk - 15-05-2016, 09:51 AM - Форум: Информационна сигурност - Без отговори

https://geti2p.net/en/

I2P е даркнет проект. Посредством криптиране на връзката и създаване на тунели към останалите участници в мрежата се изгражда анонимна мрежа. За разлика от Tor, I2P няма за цел да ви скрие от обичайното интернет пространство (clearnet), макар това да е възможно с помощта на някои изходни прокси сървъри (outproxy).

Много напомня за зората на интернет (ниски скорости, дървени сайтове), но от друга страна предлага алтернативна инфраструктура за сърфиране и споделяне на информация (предвид нарастващото влияние на корпоративни мастодонти, влошена геополитическа обстановка и т.н.).

Принтирай

  Митове за антените
Публикувано от: mzk - 25-04-2016, 10:12 AM - Форум: Антени - Без отговори

Попаднах на интересна статийка. Прикачвам съдържанието й тук, а източникът е: http://www.k0bg.com/myths.html


Цитат:Basics

There is so much misinformation floating on the Internet about antennas in general, and mobile antennas specifically, it is not surprising many newcomers are confused. Although some of the information presented here is in other articles on this web site, it is best to set them out here in an effort to correct some of the more popular myths. While some of them can be applied to base station antennas as well, the thrust here is aimed at HF mobile antennas.

Terms used here are the same as those explained in the Antenna Efficiency article which should be read first. Readers should also acquaint themselves with with the different types of grounds.

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The Band Coverage Myth

Advertising hype to the contrary, it is difficult to design a remotely-tuned antenna to cover 80 through 10, much less adding 160 and 6 meters to the mix! There are many reasons why this is so, but not the least is overall physical length. A full-length 1/4 wave, unloaded antenna for 6 meters will be about 54 inches long, and may be only 48 to 50 inches if the mast is large like those of most remotely-tuned antennas. This is slightly longer than the base/coil assembly of most screwdriver antennas.

160 Meter CoilOn 10 meters, a full-length 1/4 wave, unloaded antenna is about 96 inches long, but again may be somewhat shorter due to the mast size. Depending on the antenna brand in question, covering 10 and 12 meters will likely require installing a shorter whip. When it doesn't, it means the overall losses are higher than they should be.

Any 160 meter mobile antenna will have very poor efficiency, perhaps as low as .3%. A really good one perhaps 1%. Part of the issue is the requisite inductance of the coil. Even an antenna 13 feet in overall length will require an inductor in the neighborhood of 600 uH. Using the very best of construction techniques, maintaining a Q of even 100 is difficult. As a result, the coil losses are great enough, that impedance matching isn't necessary in most cases. When it is, the amount of reactance required will be vastly different than that required for an 80 through 10 meter antennas. Thus, claiming full coverage from 160 through 6 meters, even if it requires changing the whip length on the higher bands, is meant to sell antennas.

It should also be noted that a 160 through 10 meter antenna, will be slightly less efficient overall than an 80 through 10 meter model. If you just have to have 160 meter coverage, think about an add-on coil, like the Scorpion unit shown at right.

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What's 3 dB?

One very common comparison is the dB difference between one HF antenna, and another. As in; Oh, it's just 3 dB, or half an S unit, big deal! It may sound like no big deal, but it can be! What's lost in the translation is the effect 3 dB can have on the signal to noise ratio (SNR) on either end of the contact. In fact, sometimes, just 1 dB is enough that no copy, can turn into perfect copy. The real issue at hand, however, is just how much effort you want to put into your mobile installation.

Further, depending on one's speech pattern, increasing the peak power output of a SSB transmission by 3 dB, can result in an increase of the dynamic range by 6 dB. This is the main reason amplified signals sound louder than the change in an S meter reading would otherwise indicate.

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The DX Myth

No doubt, the single, most used reference (past the point of triteness) is the number of DX stations said antenna installation garnered. How or why this practice got started is an unsolvable mystery. As condescending as it may sound, amateurs who use their DX contacts as a reference, typically have the poorest of installations, and the worst of operating skills.

Why the number of DX stations worked has no correlation to any antenna parameter is simply this: Under the right band conditions (good propagation and low background noise level), it is possible to make on-air contacts, even DX ones, with as little a one milliwatt (1/1,000) of Effective Radiated Power (ERP). It shouldn't come as a surprise then, that on-air contacts can be made with 500 milliwatts (1/2 watt) of ERP. In fact, this is about the ERP of an average spirally-wound and/or short, stubby HF mobile antenna on 80 meters (with 100 watts input).

Compare this with a decent quality screwdriver antenna, properly, and solidly, mounted where the ERP is about 5 watts on 80 meters. The difference is a little more than one S unit (assuming you have an accurate S meter). Therefore, some argue that a lowly hamstick or short, stubby screwdriver is an adequate HF mobile antenna. But is it? Well, that depends on too many (usually overlooked) factors.

As alluded to above, one of those factors is the Signal + Noise/Noise ratio (SNR) generated in the receiver's front end. Most modern HF mobile transceivers will provide a 10 dB SNR with a signal as little as .15 microvolts (uV) above the band noise figure. As long as you can generate that level on both ends of the contact, you're home free. Since we also have to deal with background noise level on whatever band we're using, in the real world, it might take 10 times that signal level (1.5 uV) above the noise floor, and sometimes a great deal more!

So, here's the question you need to ask yourself; Will increasing my ERP by just 10 dB really be worth the effort? Perhaps an even more important question is; Will increasing my S+N/N ratio (SNR) by 10 dB worth the effort? The answers to both? Absolutely!

There is a antithesis in the second question. That is, the better the SNR, the less perceived the noise portion is. This is true whether it be man or nature made. This fact alone should give you enough food for thought to make a proper antenna selection.

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The Choke Myth

One of the most popular ancillary mobile devices is the automatic screwdriver controller. They're great safety devices too, because no intervention is required by the operator, save for pushing a button. Most of them work well as long as the RF imposed on the motor leads is properly choked. While it is true that some controllers will still function with a minimal choke, there is a hidden facet almost everyone misses.

The perceived noise level we all contend with, comes from both man made noises (RFI), and nature (background static). The consensus of opinion is that all of this noise reaches the receiver via the antenna. Pundits confirm their opinion by disconnecting the coax cable at the radio or the antenna. If you've read the Common Mode article, you already know that the coax cable can be a major contributor. If you disconnect the coax at either end, there is no longer any common mode, hence the RFI disappears!

The same is true for the motor control lines if they're improperly choked. Think of it this way. Every inch of coax and/or motor leads before the choke, are part of the antenna, and will both radiate and receive!

Here's some food for thought. Due to a preponderance of digital electronics, the insides (passenger area) of a modern vehicle is almost as RF noisy as it is under the hood! As a result, our inadequately choked control cable and coax are picking up the harmonically-rich, digital noise. This significantly reduces the SNR, and our ability to hear, even if they're not (directly) in the receive bandpass. The bottom line is, if you can't hear them, you sure can't work them!

Lastly, it pays to remember that every mobile installation will have some level of common mode, due in part to the excess ground losses we all deal with.

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HF Gain Myths

There are no viable methodologies to achieve positive gain with an HF (160 through 10 meters) mobile antenna, even when using a phased array (more on this below). That fact doesn't stop some manufacturers from claiming otherwise. For example, Stealth Telecom® (based in United Arab Emirates) sells a very-expensive antenna (≈$6,000) which resembles a large luggage rack. It mounts atop the vehicle similarly to a bicycle rack. It is configured as a magnetic loop, and is remotely tunable. Rated at 120 watts PEP (?), the manufacturer claims it has 9 dB of omni-directional gain, but doesn't give you a qualifying suffix, so the figure is meaningless. They further assert it has NVIS capability 80 through 10 meters! (See the NVIS Myth below.) All of their palaver is easily disproved by modeling the antenna with EZNEC or NEC5. If you do, you'll also find the efficiency is less than 3%, best case!

There are at least two manufacturers here in the U.S. making spirally-wound, 6 foot long HF antennas, claiming they have gain because they are a 5/8 wave length. They may indeed have wire that long wound around their fiberglass core, but that doesn't make them a 5/8 wave gain antenna. In fact, if you could wind 100 feet of wire around a 4 foot long fiberglass mast, the electrical length would still be four feet. When you see claims like these, go elsewhere.

Some misinformed amateurs argue that using two HF mobile antennas in a V configuration eliminates the inherent ground losses every mobile has. It does, but the resistive losses in the second antenna are just as lossy! Basically the same issue arises when using a two element, 1/4 wave phased array. While theoretically you can achieve a 3 dB increase over a single antenna, it doesn't address the overall resistive losses. There is even a seven-lander who claims his two element, phased array has 14.2 dB of gain. Compared to a dummy load one assumes!

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VHF Gain Myths

Far too many amateurs purchase VHF antennas based solely on their advertised gain. Adding insult, the published gain figure typically doesn't have a quantifying designator. That is to say, they just list the dB, and not the dBi or dBd (the i stands for isotropic, and the d for dipole). Without one of these designators, the figure is meaningless.

And be advised, that a +3 dB increase in ERP (effective radiated power) will not magically double the distance you can communicate over, especially when using FM (actually phase modulation in most cases). In the real world, it may take as much as 10 dB, and perhaps a good deal more, depending on several (typically uncontrollable such as Fresnel zoning) factors.

Keep in mind, that antennas don't achieve gain in the usual sense. If you feed an antenna with 50 watts, the radiated power is still 50 watts. What does happen is the radiation pattern is changed. This results in more power being radiated in a specific direction, and reduced in others. It is this differential which is expressed as gain. Further, there is a good case to be made about using unity gain (Ø dBd) antennas in a metropolitan area. The reason? The HAAT (height above average terrain) of the repeater, versus that of a mobile, requires radiating power at higher angles. As a result, 1/4 wave, unity gain antennas perform better in these situations, than their higher-gain counterparts do. This article by Danny Richardson, K6MHE, compares the differences between 1/4, 1/2, and 5/8 wave VHF mobile antennas, and their effect on radiation patterns.

There are other factors to consider as well. Almost everyone mounts their VHF antenna via a lip or clip mount. The tiny coax supplied with these types of mounts, actually has more loss than the antennas mounted on them have in gain! Worse, the phasing coils used are minuscule, and any real gain they might exhibit, is lost as heat!

Lastly, sturdiness is an often over-looked buying factor. Some Pacific Rim antennas are so poorly designed and made, that one good slap from a errant tree limb will render them useless.

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The Reciprocal Myth

The theory of reciprocity as applied to antennas, states that the transmitting and receiving antenna beam patterns are identical. In other words, any gain (or lack of it) they exhibit applies equally to transmit and receive. However, in the real world, the performance between transmit and receive is not reciprocal. This is due to a variety of reasons, not the least of which is takeoff angle. Further, improperly installed HF mobile antennas may have their radiation pattern overly distorted, which exacerbates the performance difference. There are many more variables like SNR, and ERP mentioned above. To them we add atmospheric noise, propagation phenomena, and even ground losses, to name a few.

In fact, the difference between transmit and receive performance can be rather extreme; sometimes you can hear better than you can be heard, and sometimes the reverse is true. So when you make a pat statement like, I can work any station I can hear, you're kidding yourself. However, if the statement is factual, you need a better antenna and/or mounting scheme!

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Coil Q Myth

Scorpion CoilDesigning mobile loading coils (they're really inductors) requires both science, and a goodly dose of practicality. It is also a discipline where bigger isn't always better! Here are a few salient points to keep in mind.

As coils get larger in diameter, there is more distributed capacitance, and more resistive wire losses, both of which reduces Q. Thus larger coils have a lower self-resonant point. Above the self-resonant point, a coil acts more like a lossy capacitor, than a coil. Further, anything placed within the coils electrical field will lower the Q. Large metal end caps are an example. And, the size of the wire, the plating on the wire if any, the number of turns per inch (tpi), and the coil support structure (coil form), all have an effect on the (assembled) Q.

Lower frequencies require more inductance in the coil, upper frequencies less inductance. The position of the coil within the antenna's overall length is also a variable, and the optimal position is partially reliant on ground losses. The diameter to length (D/L) ratio increases as the coil's reactance increases. Thus for optimal Q, monoband coils for the lower bands have ratios nearer to 1:5. For the upper bands, the ratio is close to 1:1. This also relates to a maximum overall length of about 15 inches on the lower bands. While monoband coils are still available, the remotely controlled (screwdriver) antenna has almost supplanted them entirely.

Assuming we're using an 80 through 10 meter screwdriver antenna, and you jump through all of the optimal Q mathematical hoops, this is what you'll discover. The coil diameter will be ≈3 inches, wound with #10 silver-plated wire, at 6 tpi, wound on a form with a dielectric constant no higher than 3, and mounted about the half way point or slightly below. The overall length of the coil will hover around 15 to 18 inches, and look just like the one in the photo. Incidentally, the Scorpion 680, and the old Predator use nearly identical coil designs.

Digressing for a moment. It is possible to build a monoband coil with a static Q as high as 450 or so, albeit rather difficult. Once the coil is mounted on the mast, and the top radiator (whip) is installed, the Q will drop. In the aforementioned case, the assembled Q hovers around 250, but may vary due to installation variables (ground loss, shunt capacitance, etc.).

The reason most antenna manufactures don't publish their Q ratings is simply because they're really low—in the 50 to 60 range! Instead, they publish bandwidths which in reality have nothing to do with coil Q. Those that do publish Q figures, often quote the coil's static Q. Once large metal end caps and/or shorting bars are installed, the Q drops drastically! In one well known case, from a static Q of 450, to an installed Q of less than 100! True screwdriver designs suffer less in this respect, unless their coil design is less than optimal as described above.

So how do you know what the assembled coil Q of your antenna really is? You don't! Measuring coil Q once the coil is installed within the antenna, cannot be done. It can be inferred, if you have the test equipment, albeit with poor accuracy. And, A vs. B field measurements are of little value.

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Coil Length Myth

As pointed out above, designing mobile loading coils requires both science, and a goodly dose of practicality. Unfortunately, some Internet, pseudo-scientists lack reality when it comes to loading coils. They incorrectly believe that a loading coil replaces a certain number of electrical degrees. That assumption is false!

The truth is, an antenna loading coil has an inductive reactance value, which cancels the capacitive reactance value, that a shorter than quarter-wave antenna exhibits. A lumped constant in other words. Thus at resonance, the resistive value of both the inductive reactance and the capacitive reactance will be equal, but opposite in sign.

Further, the RF current at both ends of a loading coil will be equal. Pundits of the coil length myth argue that it is not, and use this false assumption as proof of their theorem. They're wrong!

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The Efficiency Myth

High-frequency mobile antennas are not perfect performers, regardless of their owner's DX claims. For example, if you were to mount a 1/4 wave, 10 meter resonant antenna (8.2 feet long), made of solid silver rod, in the middle of the roof of an average vehicle, the efficiency would barely meet 90%. In the real world, it is more like 80%. In other words, 100 watts might go in, but only 80 watts are radiated. As the frequency is lowered, the efficiency drops, and rather drastically. Fact is, the average commercially-manufactured, HF mobile antenna is about 1% efficient on 80 meters. That's not a misprint; 100 watts in, only 1 watt out, and you only get that if you mount it correctly! Sure puts new meaning into QRP operation!

Short, stubby antennas, are much worse, as are thin, spirally wound ones. It is not uncommon for the efficiency level for these antennas to drop below .3% (that's point three percent!) on 80 meters, and well below this figure on 160 meters. Mount one of these antennas on a clip or clamp mount, and you can easily halve the figure; .15%.

Length matters, as does adequate coil Q, and mounting height. Do everything right, and 80 meter efficiency can be ≈6%. Don't kid yourself, this isn't as easy as it sounds. It takes length (>12 feet), a high Q coil (300+), no doubt a cap hat, and a high mounting location with lots of metal mass under it. One thing is for sure, it is difficult to explain (and justify) these requirements when the DX myth is used as a yardstick.

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The Power Handling Myth

Usually, the maximum power any given mobile antenna can handle is based solely on the Q of its coil. Depending on that Q, at some given power level, the I2R losses will exceed the dissipation loss capabilities of the coil, and the coil will fail. If the dielectric strength of the coil form or its supporting structure is exceeded, an arc can form which can also cause the coil to fail. Contamination from road debris, water, snow, and especially salt residue, exacerbate the problem.

As pointed out in the Antenna article, there are several screwdriver antennas rated at 200 watts PEP (or less!). Although they get warm during normal operation due to the rather high resistive coil losses (low Q), typically there's no permanent damage done. However, driving one with much more than 25 watts during the tuning process can result in damaging the coil assembly beyond repair! As above, the scenario is exacerbated by proper mounting (reduction of ground losses).

Remember too, resistive ground losses are in series with the other resistive antenna losses (conductor, coil Q, and radiation resistance). As the power is increased, the ground losses also increase. Remember the formula for power loss is I2R. What this says is, the more ground loss there is, the higher the transmit power can be before excessive power losses damage or destroy any given (power rated) antenna. In any case, reducing ground losses is the holy grail of mobile operation as alluded to below!

Amateurs typically purchase an antenna with a power rating perhaps twice their transceiver's capability. That's a step in the right direction, but the truth is, there will still be I2R losses turning transmit power into heat. Thus it behooves you to choose an antenna which has considerably more power handling capability than you plan to use. However, there is a caveat. Far too many antenna manufacturers over-rate the power handling of their antennas.

As pointed out in the Amplifier article, some antenna types should be avoided. For example: Any vinyl covered one especially those with large metal end caps; Any screwdriver antenna with more than 10 turns per inch, or smaller than 2 inches in diameter, or wound with less than size 14 awg wire. This includes stubby screwdrivers (except the 680S Scorpion), any Hamstick®, any Hustler®, the Opek®, and any antenna where the loading coil is mounted higher than 60% of its length.

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Ground Loss Myths

A vehicle is not a ground plane for an HF antenna. Rather, it acts like a capacitor between the antenna, and the surface under the vehicle in question. That surface, whatever it is, forms the actual ground plane, albeit rather lossy. Depending on the reference, the stated ground loss for an average vehicle varies between 2 and 10 ohms (10 through 80 meters). The real world figures are closer to 5 to 20 ohms, and may be higher on the upper bands than the lower ones. Looking at this from a different angle, the ground losses are roughly equivalent to a capacitor with a value of between .004 uF to .002 uF. Remember, the formula for capacitive reactance is frequency dependent: Xc=1/2πfC

One of the reasons ground plane-less verticals (no radials, perhaps just a pipe or ground rod) do not perform well, is because the current returned to the source is forced to travel though lossy ground. A similar situation exists in a mobile installation. That is to say, some of the antenna current returning to the source flows through the surface under the vehicle, rather than through the vehicle itself. This fact increases ground losses which are already high.

One of the base-station work-a-rounds, is to elevate the antenna away from the poor conducting ground surface, and use an artificial ground plane; elevated radials in other words. However, we don't have that luxury in a mobile installation. There is one thing we can do, and that's raise the antenna as high as possible on the vehicle (but not atop a long post!), consistent with local height restrictions (legal, trees, wires, etc.). Doing so reduces the coupling between the antenna and the surface under the vehicle, which increases the current flow through the body of the vehicle, and reduces the overall ground losses. It should be noted that a proper mobile installation will always have more ground loss than a proper base station installation, even using the exact antenna!

It should also be noted that you can't measure the ground loss directly, although they are represented as part of the input impedance of the antenna in question. Therefore, changes in the input impedance cannot be assumed to be a reduction or increase in ground losses, without a thorough understanding of the other parameters involved. Field strength measurements will give you a better comparison of the changes, but here too they have to be carried out in a scientific (all factors normalized) manner, or the results will be just as ambiguous as any input impedance measurement.

The effect can be shown graphically by using antenna modeling software like EZNEC. However, modeling programs do not calculate ground losses accurately, even in ideal situations. When they're used to model vehicle installations, ground loss calculations are even less exact, due in part to the complexity of accurately modeling a vehicle's superstructure. Thus, the often-quoted data relating to mobile HF antenna models is often contrary to empirical testing.

Incidentally, the number of modeling segments in EZNEC required to duplicate an average vehicle's real-world condition, exceeds 200. A fact which requires the full-boat, commercial version, not the free, down-loadable version. Even then, the accuracy can be poor if the ground loss figures are incorrect.

There's another important item with respect to ground losses which needs addressing, and that is consistency in ground conductivity. While the mean deviation over a large statistical area may be fairly narrow, over a small statistical area the mean deviation can be rather drastic. Adding insult, mobiles operate on paved surfaces for the most part, and road surfaces are even more inconsistent than soil surfaces.

The mean deviation in soil conductivity changes as the moisture content, and surface temperature of the ground changes. In fact, the changes are often great enough, that you can measure the difference in input impedance between morning, and evening. This fact is yet another reason antenna shootouts are not nearly as definitive as organizers would lead you to believe.

Here's one more important point to ponder. Most amateurs wouldn't think about installing a base-station dipole antenna with the elements parallel to one another (spaced 6 to 8 inches apart), with the feed point a few inches off the ground. Yet, that is essentially what they're doing when they mount an HF mobile antenna on the back of a van or SUV utilizing a trailer hitch type mount. The fact you can make contacts with such a setup doesn't mean much.

Amateurs often try to check the directivity of mobile antennas, especially HF ones, by driving the vehicle is circles, and having some distant station read out the change in S meter readings. This type of testing is fraught with problems. Instantaneous changes in propagation, localized changes in surface conductivity, poor S meter performance, and the subjectivity of the listening station make such measurements baseless!

☜Return☜

Body Myth

There are a few misguided souls who believe the body of a vehicle increases the electrical length of an HF antenna attached to it, but only if the antenna is mounted atop the vehicle! The main hypothesis seems to be that the body is a vertical structure, and akin to the lower half of a vertical dipole. This is not the case in a mobile installation, nor is it the case for a near-ground mounted vertical dipole due to mutual coupling to the ground surface below.

The body of a vehicle is an inadequate ground plane for any frequency under about 200 MHz. Thus it couples to the surface under it much like two plates of a capacitor. Since there is some resistive loss (in series with the input impedance of the antenna), a portion of the return current is radiated by the body. This radiation has little effect on far-field signal strength, but may contribute to some near-field signal strength depending on the frequency, and distance involved. This is yet another reason why field strength measurements have to be done in such a way to avoid any near-field radiation.

Radiation resistance (Rr) of a vertical antenna is a function of the electrical length, and the current distribution along that length. Series and parallel losses (ground losses and stray coupling losses respectively) are always present, with series losses the most severe. Lowering of ground (series) losses, and raising radiation resistance will result in higher efficiency, but the latter is easier to accomplish by correct use of a cap hat. However, this fact should not be construed to mean, that mounting an antenna on the top of a vehicle will increase its electrical length. It will not! It will decrease ground losses to some degree which may be of some benefit, especially if the radiator (antenna) is significantly shorter than 1/10 wave.

Incidentally, there is almost nothing you can add to the body of a vehicle to decrease ground loss. This includes adding a second antenna, however configured, as a radial or supposed counterpoise!

Unfortunately, most antenna field strength measurements are taken with the receiving antenna very close to the surface. There are questions about how effective a low measuring point is, because receiving heights close to ground level are highly effected by nearby objects, including the people doing the measuring.

☜Return☜

Radiation Pattern Myths

The angle of radiation from a horizontal antenna, is rather dependent on the ground conductivity under the antenna. This fact is why height above true ground is so important to horizontal antennas. However, when it comes to verticals, height isn't so important, as long as the ground losses are low. There are a couple of ways to accomplish this with a base-station vertical. One is to lay out a bunch of radials (at least 25 or so) under the antenna, or raise the antenna off the ground, and use a lessor number of elevated radials. Rather than insert a book-length dissertation at this point to explain why this is so, I suggest you read Rudy Severns', N6LF, series of white papers on the subject. If you want the short course, read his PowerPoint® presentation.

Vertical Pattern ChartTo quote Rudy Severns, Any practical ground system will not affect the radiation angle or far-field pattern! Rudy goes on to say, The ground system around the antenna does nothing for the far-field pattern except to increase the power radiated for a given input power.

What Rudy is saying is, a vertical without any radials will have virtually the same angle and pattern as one mounted over a perfect ground plane, albeit at a much reduced level. We can see this easily by looking at the chart on the left. If there is any change in the angle of radiation, it is due to the presence of common mode currents, and factors not directly associated with ground loss!

We can reduce the ground losses in a mobile installation by increasing the mounting height of the antenna. Two things happen when you do. First, the resonant frequency decreases, due in part to a reduction in the capacitive coupling between the antenna, and the surface under the vehicle. The ground losses decrease, as does the input impedance, basically for the same reason. The reduction in ground losses effectively increases the antenna's efficiency—a worthy endeavor! Incidentally, this is why good installations require antenna matching networks (antenna input impedance less than feed line impedance), and poor ones typically do not.

The another common myth is the level of distortion in the radiation pattern caused by the body of the vehicle. Yes, the pattern is distorted, but not nearly to the level most folks believe. Regardless of the aforementioned shortcomings of modeling software, they're fairly accurate in modeling the radiation pattern. In fact, they fairly mimic empirical testing. That is, if folks are willing to go through the necessary 200+ machinations to describe the vehicle's superstructure to assure even a modicum of accuracy. If you do the tedium, you'll discover the differences are seldom more than about 3 dB. However, the difference may be somewhat greater when modeling antennas mounted low on the back of vans and SUVs. I might add, if the modeled (or real world) measurements exceeds ≈6 dB, then a higher, less lossy mounting location and/or style is in order.

There is a related myth which needs to be dispelled. That is, that ground conductivity in areas near the ocean account for increased propagation and signal strength, and even lower angles of radiation. The truth is, the affect is largely a result of a clear horizon unencumbered by structures, and flora, albeit with a slight decrease in near field ground losses. Again, localized ground losses have no measurable affect on the radiation angle or (the) far-field pattern!

As mentioned above, when an antenna is mounted low to the surface the vehicle rests on (trailer hitch mount for example), a goodly amount of the return current is forced to flow through the lossy surface under the vehicle. If we mount the antenna higher on the vehicle, and place as much metal mass (directly) under it as we can, more of the return current flows in the body of the vehicle. This reduces, but does not eliminate ground losses. Higher mounting typically results in a 3 dB to 5 dB increase in field strength; an obvious worthy goal.

☜Return☜

The NVIS Myth

There are at least 10 web sites dedicated to NVIS. The misinformation on all of these sites, is roughly based on the same set of now declassified, but flawed data (circa 1944), from the U.S. Signal Corps. It has since been retracted. However, once something gets on the Internet, it accepted as gospel. In any case, the myth can be easily dispelled by modeling (as described above with at least 200 segments) a vertical antenna with, and without, a bent-over whip. Be careful, however, as there will be changes in the input impedance, and resonant frequency. Proponents misconstrue these changes as support for the myth. Or, they site S meter readings, which are suspect at best.

What's more (in difference to on-line resources), NVIS is very difficult to accomplish at frequencies higher than about 5 MHz, and impossible over 8 MHz. Yet, at least two antenna manufacturers openly state their antenna's NVIS capability up to, and including 30 MHz. Perhaps the only bigger myth, is the SWR myth!

☜Return☜

The SWR Myth

MFJ-259BThere are several inexpensive ways to measure an antenna's input impedance with a fair degree of accuracy, typically ±5%. The MFJ-259B is one. If you have, and know how to use, antenna modeling software like EZNEC, you can get fairly close to an antenna's real-world efficiency by comparing the measured parameters against calculated ones.

If you have the acreage, the right kind of test equipment, a fair knowledge of antenna theory, some cash liquidity, and a whole lot of time on your hands, you can even measure the signal strength at any given angle of radiation within a few percentage points. Alas, most amateurs don't have these facilities, so they resort to the SWR myth.

Measuring the SWR is an easy task, so I suspect this is why neophytes often use SWR as a means of quantifying and qualifying their antennas. The truth is, a low SWR means nothing other than your transceiver will be happy! Maybe!

One thing is for sure, it will not give you the true resonant point, unless the antenna's input impedance (at resonance) is exactly R50 +jØ; a very rare occurrence indeed! Fact is, it is possible to damage some transceivers even though the SWR appears to be low.

☜Return☜

The SWR vs. Resonance Myth

2:1 SWRA very common belief is that the lowest VSWR point is always the exact resonant point. This is a myth! For example, an unmatched, HF mobile antenna, of decent quality, will have an average input impedance of ≈25 ohms at resonance. This represents an VSWR of 2:1. This fact can be easily demonstrated by measuring the input impedance with an antenna analyzer.

SWR CurveBy definition, an antenna's resonant point will be when the reactive component (j) is equal to zero (X=Ø, or +jØ). At that point in our example shown at left, the R value reads 23 ohms, and the SWR readout will be 2.1:1 (actually 2.17:1). If we raise the analyzer's frequency slightly, the reactive component will increase (inductively) along with an increase in the resistive component, hence the VSWR will decrease, perhaps to 1.4:1. In this case, the MFJ-259B is connected to an unmatched, screwdriver antenna mounted on the left quarter panel, and measured through a 12 inch long piece of coax. This fact is shown graphically in the image at right.

Depending on the transceiver in question, the resulting reactance may or may not cause any major problems, but it is still advisable to properly match your antenna. It should be noted, however, if your antenna doesn't require matching (input impedance ≈50 ohms), you need a better antenna and/or mounting scheme!

Looking at this another way. You measure your antenna's SWR with an SWR bridge, and it's 2:1. If there is no reactance present, then the input impedance of the measured antenna could be 25Ω (typical for a short HF mobile antenna), or it could be 100Ω. It could also be 50Ω ±35j. The only way you would know if there was reactance present, would be to use an antenna analyzer instead of the SWR bridge. Because of this issue, the SWR readout of any antenna analyzer should be ignored while attempting to match a mobile antenna!

If the input impedance of an antenna is other than 50 ohms non reactive (50R +Øj), any length of coax inserted between the antenna, and the antenna analyzer (or VSWR bridge), will skew the readout results. The amount of skew depends on the magnitude of the mismatch, and the length of the coax in question. For this reason, antenna analyzer measurements should be taken as close to the antenna as possible.

☜Return☜

Coaxial Myths

Coax ChokeCoaxial myth one: The coax feed line must be a specific length. Several antenna manufacturers suggest using a specific length coax cable between the transceiver, and the antenna, or they suggest using an open stub cut to some length. Both of these schemes are SWR patches, not fixes. Shunt matching is the only correct way to match a remotely tuned HF mobile antenna to 50 ohms. If you read the article, you'll know why.

Coaxial myth two: Using the best grade of coax money can buy, will be worth the expense. Not! There are two aspects of this myth. First, the the length of coax used in the average mobile installation, seldom exceeds 10 feet. Thus the difference between say RG213, and RG8X, is less than .25 dB! Ah, but there is a hidden facet as well! As mentioned above, it is very important to properly choke off common mode currents from coaxial feed lines, especially mobile ones. In order to duplicate the common mode choke shown at right (7 turns, 3/4 inch ID, mix 31 split bead, ≈2.2 kΩ @ 10Mhz) on RG213, would require 49 similar split beads. That's about $250 worth, instead of just $5! By the way, serial bead chokes tend to be mostly inductive, rather than mostly resistive over their bandwidths, which reduces their common mode effectiveness.

Coaxial myth three: A low SWR in mandatory! The truth is, any SWR under 1.6:1 is A-OK. In fact, flattening the SWR down to 1:1 will make an insignificant change in ERP. And typically, common methods used to further decrease the SWR will result in more overall losses, not less! This includes using built in or external antenna tuners. The justification for this inanity, is the fact that SWR changes as we drive. But the truth is, no antenna tuner tunes fast enough to match these nearly instantaneous changes in ground loss.

☜Return☜

The Bandwidth Myth

In a general sense, with respect to HF mobile operation, wider bandwidth usually relates to lower efficiency, but not always as some believe. For example, if we use a shorted stub to impedance match an HF mobile monoband antenna, the 2:1 bandwidth edges will expand, perhaps by double. This is due to the frequency versus reactance curves of the stub, and the antenna being opposite of one another. However, like capacitive matching, stub matching is monoband in nature.

Worse, one manufacturer taunts the bandwidth of their high-powered coils as a selling point. The truth is, the large end caps reduce the Q of the coils below that of their standard sized ones. The point here is, be careful of advertising claims about bandwidth.

This always raises a question about what the 2:1 or 3:1 bandwidth should be. Well, here's the truth. Two, otherwise identical installations, will have different bandwidths. Why this is so, lies in what comprises an (relatively speaking) efficient HF mobile antenna.

There is a formula circulating the Internet which states that antenna Q is equal to 360 times the frequency in MHz, divided by the 2:1 VSWR bandwidth in kHz. One has to assume they mean antenna system Q, but that's not a given. The truth is, the actual Q of the antenna (system or otherwise) requires a textbook-full of formulas, and a lot more information than just the 2:1 bandwidth!

Using a properly-mounted cap hat will always increase both bandwidth and efficiency, and in some cases, drastically! An improperly-mounted one will also increase bandwidth, but efficiency will suffer just as drastically! These facts are why it is so important to properly design, and install cap hats. If you read the article, you'll know why some impressive designs are such lousy performers. And, considering the ever-increasing popularity of remotely-tuned HF mobile antennas, the bandwidth, 2:1 or otherwise, becomes all but moot.

☜Return☜

The Hole Myth

Lip MountJustifying one's no-hole installation by using trite references to leases, wives, and depreciation value, is inane. Yes, sooner or later, drilled holes might have to be repaired depending on a lot of unknown factors (vehicle mileage and/or condition for example). However, a no-hole installation can be just as costly, perhaps more so.

The damage to the trunk lid should in the left photo is obvious, but the damage to the quarter panel is less so. Repairing this type of damage isn't going to be inexpensive, especially if the trunk lid has to be replaced. But this isn't the only damage which can occur.

The antenna in question is a Yaesu ATAS120. From the get go, it is not a sturdy antenna in any respect. Each time the trunk lid is opened and closed, stress is placed not only on the mount, but on the antenna as well. What's more, trunk lip mounts allow the antenna to sway back and forth, further exacerbating the body damage, and the mechanical stress place on the antenna.

Another popular way to avoid drilling a hole is to use a mag mount. However, there are a couple of hidden problems with them. First, there is no RF ground connection. As a result, the coax cable radiates a large percentage of the radiated power (via common mode currents flow), and its pattern includes the interior of the vehicle it is mounted on! The other is the fact they collect road debris, typically metallic particles from brake shoes. Add in a little acid rain, and they leave circular patterns in the paint often referred to as mooning. Regular cleaning doesn't help either, and after a few months use, the moons standout like a sore thumb.

Here is something else to consider. Rather than base your no-holes installation on trite references, base it on sound engineering practices, with a mind set towards what if... And that what if should include safe operation, ease of requisite repair, and associated long-term costs.

Conclusion

For some, it is easier to believe myth, than fact. If you're not one of them, and you want to have a better understanding of antennas, particularly HF mobile antennas, then the real key is to learn the theory behind them. The best way I know how to do that, is buy yourself an ARRL Handbook. Read it cover to cover 3 or 4 times, and enough will rub off that you'll know more than most licensed amateurs

Принтирай

  Изкуствено увеличаване на малки антени
Публикувано от: mzk - 24-04-2016, 08:29 PM - Форум: Електричество и магнетизъм - Отговори (1)

Идеята е антени, значително по-малки от работната дължина на вълната да се захранят по начин, който ще позволи работата им като стандартни антени (1/4 и подобни).

Източник:
http://amasci.com/tesla/tesceive.html
http://amasci.com/tesla/nearfld1.html

Забележка: за статията с всички линкове моля отворете източника.

Код:
          
'Energy-sucking' Radio Antennas,
N. Tesla's Power Receiver

   Here's something that has always bugged me: light waves are about 5000 Angstroms in wavelength, while atoms are more like 1 Angstrom across. Atoms are thousands of times smaller than light waves, yet atoms obviously interact very strongly with light. How can they do this? Perhaps they get around the problem by employing Quantum Mechanics (photon-physics rather than EM waves?) There must be some explanation. After all, when a metal dipole antenna is only one foot long, it certainly cannot absorb much 5000ft-wave radiation. I never encountered a good explanation for this during my physics education. I finally found a couple of physics papers that make things clear. And it's not QM that solves the problem. It turns out that the real explanation is both little-known and fascinating.

PAGES:
1. Jump down to full article
2. Antenna Nearfield, Clearer diags & description
3. More Musings about this topic...
4. Links
below 5. some email discussions
6. Whaa? What if photons don't actually exist?!!     
PERPETUAL MOTION?!! Strangely, several people have made the mistaken assumption that this article is about a perpetual motion machine. Why leap to such a conclusion? Who knows. Perhaps I need to point out that in Fig. 2 and Fig. 3, the "10 megavolt supply" is a distant radio transmitter (an EM energy source, powered by the utility grid.)

This article is about the ability of an LC resonator to "funnel" incoming electromagnetic waves towards tiny antennas. These antennas behave as if they were much larger than their physical diameter, as if there was an "invisible lens" focusing more of the incoming EM energy upon the antenna. In conventional terms, it's about enhancing the EA (effective aperture) of 'electrically small' antennas.
    

CONTENTS

   Atomic absorption: And oddity
   Transmit in order to Receive?
   Not so crackpotty...
   How DO atoms do it?
   Almost a 'hole' in physics
   1-dimensional model
   1-dimensional model w/resonance
   Unexpected power
   Conclusions
   Tesla connection
   What good is it?
   A hole in textbooks

   An Update
   Some Implications:
       Ears emit anti-waves?
       Ball Lightning
       Loose-coupled transformers
       Mechanical resonators
       Pranks!
   References
   comments from email
   Bill b article: Light without photons (NEW 9/99)

    
     

HOW DO ATOMS DO IT?
I stumbled across the answer to my questions in a paper about Nasa's VLF/ELF loop antennas. Apparently Quantum Mechanics does not supply the answer. Instead the question of small antenna behavior is resolved by a little-known section of classical electromagnetism. It involves resonance, but more importantly, it involves the magnetic and electric fields which surround any antenna. (I guess I should have expected this. After all, much of physics works fine with classical concepts, with photons and EM waves both explaining the same phenomena.)

An "electrically small" antenna is one where the physical antenna size is far smaller than the EM wavelength being received. At first glance, electrically small antennas aren't all that strange. If we use them to transmit radio waves, they work just as you'd expect. In order to force a tiny antenna to send out a large amount of EM energy, we can simply give it a huge driving signal (high voltage on a tiny dipole, or high current on a tiny loop antenna.) If the EM fields are strong at a distance of 1-wavelength from the small antenna, then the total EM radiation sent out by the antenna will be significant. It's almost as if the EM fields themselves are acting as the antenna. Weak fields act "small," while intense fields behave as a "large" antenna. This explains how a tiny antenna can transmit lots of EM. But what about reception?

It turns out that a similar idea works for reception; for "input" as opposed to "output." By manipulating the EM fields, we can force an electrically-small receiving antenna to behave as if it was very, VERY large. The secret is to intentionally impress an artificial AC field upon the receiving antenna. We'll transmit in order to receive, as it were. Conventional half-wave antennas already do exactly this because their electrons can slosh back and forth, generating their own EM fields. For example, the thin wires of a half-wave antenna are far too thin to block any incoming radio waves and absorb them. However, the current in such an antenna, as well as the voltage between the two wires, these send out large, wide, volume-filling EM fields which have a constant phase relative to the incoming waves. Because of the constant phase, these fields interact very strongly with those incoming waves. They create the lobes of an interference pattern, and this pattern has an odd characteristic: some of the incoming energy has apparently vanished. The fields produced by the antenna have cancelled out some of the energy of the impinging EM waves.


TRANSMIT IN ORDER TO RECEIVE?!!!
Rather than relying upon the wiggling electrons in the wires of the large half-wave antenna to generate EM fields... what if we used use a power supply instead? If an antenna is 1/10,000 wavelength across, we should be able to force it to behave as if it's huge; perhaps 1/3 wavelength across. We simply have to drive it hard with an RF source. We must drive it at the *same* frequency as the incoming waves, then adjust the phase and amplitude of the power supply to a special value. At one particular value, our transmissions will cause the antenna to be best at absorbing the incoming waves.

Take a loop antenna as an example. If we want our little loop-antenna to receive far more radio energy than it normally would, then we need to produce a large AC current in the antenna coil, where the phase of this current is locked in synch with the waves we wish to receive, and is lagging by 90 degrees. The voltage across the antenna terminals stays about the same as when an undriven antenna receives those waves. However, since the current is much higher in the driven antenna, the energy received per second is much higher as well. This seems like engineering blasphemy, no? How can adding a larger current increase the recieved power? And won't our receiving antenna start transmitting? Yet this actually does work. Power equals volts times amps. To increase the RF power received from distant sources, we increase the antenna's amperes intentionally.

This sounds really silly. How can we improve the reception of an electrically small antenna by using it to *transmit*? The secret involves the cancellation of magnetic or electric fields in the near-field region of the antenna. The physics of the nearfield region of antennas has a kind of nonlinearity because conductors are present. In the electromagnetic nearfield region, it's possible to change the "E" of a wave without changing the "M" (change the antenna's voltage without changing the current), and vice versa. Superposition of EM traveling waves does not quite apply here because the ruling equations for energy propagation near conductors depends upon V^2 or I^2 separately. In addition, V is almost independent of I in the near-field region. If a very small loop antenna (a coil) should happen to receive a radio wave as a very small signal, we can increase the received *energy* by artificially increasing the current. Or if we're using a tiny dipole antenna (a capacitor,) we can increase the short dipole's received energy by applying a large AC voltage across the antenna terminals.


NOT CRACKPOTTY AFTER ALL
Note that this does not violate any rules of conventional physics. If we add stronger EM fields, they sum with the incoming EM plane waves and cause these radio waves to bend towards the tiny antenna, and the antenna absorbs them. This increases the antenna's EA (effective area, or effective aperture.) We can use this process to alter the coupling between the antenna and the surrounding space, but the total energy still follows the conservation law. The altered fields only change the "virtual size" or EA of the antenna.

More importantly, the phenomenon is quite limited. We can only use it with electrically "small" antennas. We cannot increase the "virtual size" much beyond a quarter wavelength for the waves involved. If we already have a large 1/2-wave dipole, then no matter how large is our artificially-add AC voltage, we cannot make it absorb more incoming waves. However, if we have an extremely small antenna, say, a 10KHz loop antenna the size of a pie plate, we can make that antenna seem very, very large indeed. Think like this: how large is the diameter of the antenna's nearfield region at 10KHz? Around 10 kilometers? What if we could extract half of the incoming energy from that entire volume?!! In theory we can: half can be absorbed, and the other half scattered. In theory a tiny loop antenna sitting on your lab bench can intercept just as much energy as a longwire 1/2-wave antenna which is 10KM long. Bizarre, eh?

Here's a way to look at the process. If I can create a field which cancels out some of the energy in an extended region surrounding a tiny antenna, this violates the law of Conservation of Energy. Field energy cannot just vanish! That's correct: if we cancel out the energy in the nearfield of an antenna, this is actually an absorption process, and the energy winds up inside the antenna circuitry. By emitting an EM field, a receiving antenna sucks EM energy into itself. If we actively drive an antenna with an "anti-wave", we will force the antenna to produce stronger fields which cancel the incoming waves, and simultaneously the antenna absorbs more energy from the EM fields in the surrounding region of space than it ordinarily would. It also emits some waves of its own. But in antenna theory these waves are identical to the received signals, and they are considered to be reflected or "scattered" from the antenna. It's a general law that we cannot receive EM waves without scattering half of the energy away again.

Here's the interesting part. If we wish to receive power rather than signals, a critical issue arises.

Driving a tiny antenna with a large signal will create large currents and heat the antenna. Small antennas are inefficient when compared to half-wave dipoles. If we wish to maximize the virtual aperature of a really tiny antenna (e.g. make our 10KHz pie-plate coil act 10KM across,) we'll quickly be frustrated by wire heating. All the extra received energy will go into warming the copper. Possible solutions: use superconductor loops, or at low frequencies use the nearest equivalent to an AC-driven superconductor: a rotating permanent magnet or rotating capacitor plates.


BUT HOW DO ATOMS DO IT?
OK, if this supposedly explains how tiny atoms can receive long light waves, how can we increase the voltage signal to a single atom?! Actually it's not difficult. No angstrom-sized radio transmitter is needed. The key is to use EM energy stored as oscillating fields; i.e. resonance.

If an atom resonates electromagnetically at the same frequency as the incident light waves, then, from a Classical standpoint, that atom's internal resonator will store EM energy accumulated from the incoming waves. It will then behave as an oscillator, becoming surrounded by an increasingly strong AC electromagnetic field as time goes by. (Quantum Mechanics might say that the atom is surrounded by virtual photons at the resonant frequency.) If this alternating field is locked into the correct phase with the incoming light wave, then the atom's fields can interact with the light waves' fields and cancel out quite a bit of the light energy present in the nearfield region around the atom. The energy doesn't vanish, instead it ends up inside the atom. Half of the energy goes into kicking an electron to a higher level, and the other half is re-emitted as "scattered" waves.

By resonantly creating an "anti-wave", which superposes with incoming waves and bends them towards the atom, the tiny atom has "sucked energy" out of the enormously long light waves as they go by. And since the atom has no conventional copper coils inside it wasting energy, it can build up some really strong fields which allow it to behave extremely "large" when compared to it's physical diameter.

Impossible? Please track down the C. Bohren paper in the references below. He analyzes the behavior of small metal particles and dielectric particles exposed to long-wave EM radiation, and rigorously shows with semi-Classical analysis that the presance of a resonator can cause dust motes to "act larger than they really are."

How can this stuff be true?! After all, electric and magnetic fields cannot bend other fields. They cannot affect each other directly. They work by superposition. For the same reason, a light wave cannot deflect another light wave. Ah, but as I said before, the mathematics of the fields around a coil or a capacitor are not the same as the mathematics of freely-propagating EM waves. If we add the field of a bar magnet to the field of a radio wave, and if the bar magnet is in the right place (at a spot where the phase of the b-field of the radio wave is reversing polarity,) then the radio wave becomes distorted in such a way that it momentarily bends towards the bar magnet. And then, as the EM wave progresses, we must flip the magnet over and over in order to keep the field pattern from bending away again during the following half-cycle. The energy flow continues to "funnel in" towards the rotating magnet. Now replace the bar magnet with an AC coil, and vary the coil current so the fields stay locked to the traveling radio wave in the same way. In that case the wave energy will always bend towards the coil and be absorbed. Superposition still applies, but this is a coherent superposition, so it acts like a static field pattern: as if a permanent magnet can bend a radio wave inwards and absorb its energy rather than simply having the fields sum together without interesting results.

Note that the coil will also emit its own EM ripple. This emission is well known: atoms ideally will scatter half the light they absorb, and dipole antennas behave similarly: they scatterer incoming EM waves as they absorb part of the energy. When all is said and done, our oscillating coil has absorbed half of the incoming EM energy and re-emitted (or "scattered") the rest. In a phase-locked system, we cannot tell the difference between reflection and transmission.


A "HOLE" IN PHYSICS
When viewed as a halfwave receiving antenna, a resonant atom acts as if it has expanded in size to fill its entire nearfield region. In terms of Quantum Mechanics, it does so by locally creating a large virtual-photon AC field which normally would not exist. Because of coherent superposition, in a sense this new field becomes the antenna. The significant part of this new field extends to (Pi*wavelength)/2 distance around the atom, and this distance can be thousands of times larger than the atom's radius. A 1-angstrom atom with a large AC field can behave as a 1/3-wave antenna at optical frequencies. Though tiny, the atom can absorb "longwave" radiation such as light. Our 1-angstrom atom becomes a black sphere 2000 angstroms across, and efficiently absorbs 6000-Angstrom light waves. Very strange, no? I've certainly never encountered such a thing during my physics training. Apparently the missing details of the absorption of light wave by atoms is a "hole" in physics education, and it has only been treated in a couple of contemporary physics papers in the 1980s. Here's another hole: when an atom absorbs waves, it has to scatter away half the energy. Does this mean that when an atom absorbs a photon, it must always interact with TWO photons, eating one and reflecting the other?!!!! I've never heard of such a requirement. It flys in the face of the usual description of atoms and photons. (Is it mentioned in Feynman's QED book?)


    
[Parallel lines flow in from the left, bend inwards, and dive into a central point]
Fig 1. Energy flux lines for the nearfield region of
a resonant absorber. The tiny absorber acts like
a large disk.
[from ref#4]

     This "energy suction" effect is not limited to atoms. We can easily build a device to demonstrate the phenomenon. Below is a simple physics analogy to show how tiny atoms can "suck energy" from long light waves. Suppose we transmit a VLF radio signal at 1KHZ frequency. Let's arbitrarily set the signal strength so it's about the same strength as the Earth's weak vertical e-field: 100 Volt/meter. If the transmitter's e-field is contained entirely below the conductive ionosphere, and if the bottom of the ionosphere is about 100Km high, then the Earth's entire vertical field is about 10 megavolts top to bottom. Our transmitter must produce such a field. These values aren't totally ridiculous. Large, well-designed Tesla coils commonly produce 10 megavolts. If such a coil was erected outdoors and connected to an insulated metal tower, it would fill the Earth's entire atmosphere with 1KHz radiation. The Earth's atmosphere would be like a microwave oven cavity. Such an AC voltage field would produce a feeble 100V/M field everywhere on the Earth's surface. This field would be detectable by instruments, but otherwise it would be too small for humans to notice, and we certainly would not expect to be able to get significant power out of it.


CAPACITIVE-PLATE ANTENNA
OK, we've got a feeble AC e-field in the outdoor environment. How will a simple antenna-plate perform as an energy receiver? See fig.2 below. If it's a large horizontal metal plate about one meter off the ground, it will give out a 100 volt signal at 1KHz, but this one hundred volt "power source" has an extremely large capacitive series impedance. Let's say that the plate/ground capacitance is 10pF. To draw energy with the maximum possible voltage, the load resistor should be approximately equal to the series impedance. This impedance is dominated by the 10pF capacitor value, so this gives 1/(2*PI*F*C) = 16 megohm load resistor, and it drags the antenna's voltage down from 100V to 70.7V. The received energy in the resistor is 300 microwatts, and the current in the resistor is in the microamp range. Just as we might expect, everything here is similar to a conventional radio antenna. The weak e-field from the incoming EM waves behaves only as a "signal", and it is not a source of significant power. It can't drive a motor or light an LED.

    


 __________  -->
| 10 MVolt |_______
| @ 1KHz   |       |
|__________|       |      Capacitance from
   |            ___|___   ionosphere to plate
  _|_                     ( very small,
 ////           _______    say 1/10,000 pF )
                   |    
                   |    <--- 70.7V @ 1KHz
                   |______________
    antenna        |              |
  (metal plate) ___|___           \
                         10pF     /
                _______           \
                   |              /
                   |______________|
                  _|_       16.7 Megohm
                 ////

     FIGURE 2

     

The fundamental problem with the above system is that the empty space around our metal plate is acting like a voltage divider. If the sky has 10 Megavolts compared to ground, and if the metal plate is a few feet above the surface of the ground, then the plate only has a relatively tiny voltage. Current is tiny, so wattage is also tiny. Maybe we could power an LED flasher with this antenna... but only if we set it to flash every few minutes. Maybe if we erected an enormous antenna tower we could do better by lifting the plate higher from the ground (but with such a huge antenna, we could easily steal more power by ignoring our 1KHz broadcast, because many high-power conventional AM radio stations exist: BBC shortwave, Voice of America, etc.)


RESONANT ANTENNA
Now let's add a tuned circuit to the above schematic and see what happens:

    

 __________  -->
| 10 MVolt |_______
| @ 1KHz   |       |
|__________|       |
   |            ___|___     Capacitance from ionosphere to plate
  _|_                       ( very small, say 1/10,000 pF )
 ////           _______
                   |
                   |
                   |_____________      <---  10 Megavolts!
                   |            |
   antenna         |             \_
  (metal plate) ___|___          (_)
                         10pF    (_) Coil
                _______          (_)
                   |             (_)
                   |             /
                   |____________|
                   |
                  _|_      1KHz resonant, infinite Q
                 ////

     FIGURE 3

     At resonance, the 10pF capacitance of our metal plate effectively vanishes. At resonance, an ideal parallel-resonant circuit behaves like an infinite resistor. If the LC circuit is exactly at resonance, and neglecting the resistance of the wires involved, how high will the voltage on the metal plate rise? It rises to ten megavolts!!!! The resonant circuit will continuously accumulate EM energy until the voltage at the antenna-plate rises to the same value of voltage as the transmitter. Weird!

Keep in mind that this device is a relatively small affair sitting in your back yard. It's not a 1KHz quarter-wave dipole tower 25 miles tall. There's no huge antenna, so we would not expect to find any huge level of electric power appearing in the circuit. If we weren't aware of the mechanism behind this, all we'd see is a passive LC resonator which seems to burst into oscillation of its own accord, and the voltage grows higher and higher until the darned thing suffers a corona outbreak or something. Lightning bolts shoot out! The EM fields near the metal plate grow far stronger than the weak fields already present in the environment. The device in our back yard resembles an impossible "perpetual motion" machine, which might make physicists suspect a hoax. However, the real explanation is completely conventional, and the source of the energy is a feeble, unnoticed AC e-field field produced by the very distant 10-megavolt transmitter tower. Note: the above phenomenon can only occur for an ideal LC circuit, where the resistance of the coil is zero and where the Q of the circuit is infinite. If our antenna plate were connected to the resonant "secondary" of a superconductive Tesla coil, we might in fact see the output voltage grow to the megavolt range. However, in most real-world tuned circuits it wouldn't reach such heights.

But remember, voltage is not energy. What will be the realistic behavior of such a device? Perhaps the incoming power is still small (maybe like 300 microwatts we saw earlier), or perhaps it works well, yet it takes months to build up so much voltage across even a superconductor resonator Just what is the actual received energy flow? Let's put a resistor across the tuned circuit so we create a flow of real energy and drag the voltage down to, say, .707 of the unloaded voltage. The resistance should equal the impedance of the series capacitor: 10 ^ -16 Farads, giving 1600 giga-ohms. (A huge resistor. Clearly it makes sense to try instead to extract energy using a low-value resistor in series with the inductor coil, rather than using a huge parallel resistor across the tuned circuit. A 1.6 tera-ohm power-resistor might be hard to find in the surplus parts catalogs! That is, if you don't have the parts- catalog featured in THIS ISLAND EARTH, that old SF movie where the two engineers build an "Interociter" from parts sold by mail-order in a strange electronics catalog. Obviously the Interociter is Alien Tesla coil technology, aha!)

Ahem. :)


HUGE RECEIVED POWER
With our 1.6 giga-megohm resistor in place, the RF power intercepted by the small metal plate is now 30 watts. That's 100,000 times higher than the power from the simple non-resonant antenna plate. Our tiny antenna has essentially reached out and made a kind of "direct contact" with the distant transmitter. By changing its own impedance, it has converted the femtofarad "sky capacitor" into an efficient coupling device. It has sent out a cancelling wave and pulled in energy from an enormous volume encompassing the surrounding fields. It has become a "matching transformer" which steps down the 10MV sky voltage and steps up the "sky current." If we either increase the receiver plate's size, or lift it up high on an antenna tower, or connect it to a beam of x-rays which produce an ionized pathway extending vertically upwards, then the received power rises proportionally.

So, connect a high-Q resonator to a small antenna, and you'll drag in far more wave energy. Simple?

[The engineers on SCI.ELECTRONICS.DESIGN forum have pointed out that the 10MV voltage limit on the above resonator is wrong. In reality, it can grow much higher than the voltage on the transmitter. The system is actually series-resonant, so the output voltage is limited only by the Q of the system (by the resistance of the wires in the resonator coil) and is not limited by the 10MV drive voltage of the distant transmitter.]

In our earlier antenna, (the nonresonant, resistor-only version,) a small amount of "real power" did take a path through the capacitance of the sky while on its way to the metal plate and to the load resistor. If the voltage across that resistor could be forced to oscillate hugely, and if it had the right phase compared to the tiny displacement current coming from the transmitter, then we'd obtain a major increase in energy flow. The tiny sky-current would remain about the same, but with the much larger voltage on the antenna, the value for V*I is increased and wattage is increased. Remember the unwanted capacitive-voltage-divider effect in figure 2? With a resonant system, that effect would no longer apply, and the output voltage would no longer be so low. Things would behave differently. The displacement-current going through the "sky capacitor" might still be microamps, but if the tuned circuit can alter the high voltage at our end of the transmission system, then it can drastically change the energy throughput. As with any power-transmission system, we can put more power through it by raising the line voltage while keeping the current the same.


CONCLUSION
To sum up: we see that by putting a big AC voltage on the tuned circuit and by adjusting its phase in relation to the tiny incoming current, we can "suck" the E x M wattage from the enormously broad wavefronts of the incoming waves. It also works this way inside a simple circuit using conventional voltage dividers: add a resonant circuit, and the series impedance of the power source behaves smaller. See this example circuit. It should still work this way even when a part of the antenna circuit contains a series capacitor whose dielectric is made up of many feet (or even tens of km) of empty space. It's very much like building a high-voltage power line: to transmit high wattage on a thin wire, we use high voltage at low current, and then we put a step-down transformer at the far end of the power line. However, in the "power line" shown in the above diagram, we then put a tiny capacitor in series with the high-voltage line. Then we increase the thickness of the capacitor's air-dielectric until dielectric is miles thick and the current in the system is mostly composed of displacement current in the empty space between the pair of widely-separated capacitor plates. To transmit significant power, step the voltage up to astronomical levels at one end, then step it back down at the other end. Rather than using only a step-down transformer in the receiver, instead we use a hi-Q resonator, and we allow the resonant voltage to rise to a huge value. As a result, EM energy will be "sucked" into the receiver.


THE TESLA CONNECTION
Note that all of this stuff comes directly from Nikola Tesla's "Wireless power" transmission scheme. If we can flood the atmosphere with VLF 2KHz standing waves, and if the ionosphere keeps most of this EM energy from escaping into space, then a small, high-Q resonator can grab significant wattage right out of the air. A small resonator can produce an extensive and intense AC field of its own, and can act as an "EM funnel" which grabs significant wattage right out of the ambient radiation field. It can do so even when the ambient field is quite feeble, and even when the transmitter is thousands of KM away. This is not "radio," where wavelength is the same size as the components. This is "circuitry", where wavelength is huge, and circuits are small, and the antenna operation more resembles "AC wiring" rather than "EM radiation." This is probably the concept that put that "Mona Lisa grin" on photographs of old Nikola. And that twinkle in his eye...

If we use a metal loop-antenna instead of a metal capacitor plate, then the current in the loop can perform a similar task as the voltage on the plate in figure 3: the oscillating current should grow huge and surround the coil with an intense, volume-filling AC magnetic. If the phase is correct, this b-field should "suck energy" from the transmitter (or from the local b-fields of the incoming electromagnetic waves.) Keep in mind that all this applies to small antennas. If your wavelength is 150MHz and your antenna is 1 meter across, then "energy sucking antennas" cannot be used to improve reception. The idea applies to the longwave bands, to longwire antennas, and to VLF power transmission using the Earth-ionosphere Schumann resonant cavity.

These sorts of antennas obey circuit-physics, not the physics of EM waves in space. The region of space adjacent to any antenna obeys a combination of circuit-physics and wave-physics, (the near-field and far-field EM equations,) and I've never quite visualized exactly how this works. Now it looks like there are several interesting things hidden between the near-field and the far-field mathematics. For example, simple crystal radios have "energy suckers" instead of "tuners." And everyone owns invisible antennas a thousand meters across... generated by every AM portable radio! Cool.

NOT SO USEFUL?
The "energy grabbing" effect is very limited. It's a weird laboratory curiousity. It's useful for physics education, and you can build a "Selectenna" AM/shortwave product. But to do the really impressive things you'd need almost astronomical values of "Q." Large superconducting loops. A small coil made from cheap everyday materials won't be very impressive. To perform the apparent magic you'd need massive superconductor devices and really immense AC magnetic fields. (Perhaps large heavy arrays of rotary Rare Earth magnets might substitute? Levitate and spin 'em in a vacuum chamber.)

It's also limited because it's a nearfield effect. It could only operate within about a 1/6- or 1/4-wavelength radius around a coil or capacitor antenna, or in the region between the peaks of a propagating EM wave. In other words, when we add a tuned circuit, we can increase the "effective size" of a tiny antenna until it resembles a half-wave dipole antenna. It usually would be easier to simply build a half-wave dipole in the first place. Normally we would do so.

At VHF or UHF frequencies, a hi-Q "energy sucking" resonator antenna would not gather any more energy than a normal antenna, since the hi-Q antenna would be electrically large. But whenever the conventional dipole antenna might end up being too large to construct (like at 1KHz frequency or even 550KHz), then a high-voltage capacitor plate antenna, (or perhaps a tuned-coil antenna, both with a very high Q-factor, with inductors wound from thick copper pipe?) ...these would behave like far larger antennas than anyone could possibly imagine.


NOT IN YOUR PHYSICS BOOKS?
In hindsight, the above stuff seems somewhat obvious, but why have I never heard of it before? Atoms must transmit before they can receive photons? (Laser/Einstein insights!) RESONATING ANTENNAS BECOME ABNORMALLY EFFICIENT RECEIVERS?! And perhaps the reverse must also be true: high-field, high-Q resonant antennas will leak radio waves, even if their size is very small compared to the wavelength. If resistive losses don't halt them, their AC fields will grow in intensity until the signal finally does escape. Do most radio designers realize that all small resonant antennas with huge EM fields act like long-wire antennas having fields of the usual strength? Do Ham radio operators currently use 80-meter transmission antennas having high-Q resonators and enormous magnetic or electrostatic fields? Do AM radio companies know that their antenna towers are really not necessary, and could be replaced with a cryo-coil in a small shed? Do science teachers realize that even the simplest "crystal radio" can only drive a pair of headphones when a tuned circuit present? (The tuned circuit in a crystal radio is *not* a bandpass filter: it is an energy-suction device!) Do physicists really grasp, at a gut level, just how those tiny atoms can absorb and radiate the huge wavelengths associated with light waves? And are physicists aware that two photons are needed for atomic interaction: one to be absorbed, and one to be scattered?

Portable AM radios already employ tuned resonant-loop antennas, and they've always been this way. We've been carrying around Nikola Tesla's power-receiver in our back pockets since the 1960s. Also, in bygone decades, those old "regenerative" and "superregen" receivers were not what they seemed. They were transmitting in order to receive, they were harnessing the same bizarre "energy sucking" process. Regeneration isn't just a fancy way to amplify a small signal, instead it increases the incoming signal intercepted by a short antenna via some weird EM physics. Do the designers of 90 years ago know something that modern scientists do not?


UPDATE 9/6/99
In thinking more on this (and while talking to people on the email lists) a couple of new thoughts have occurred to me. One: try to give your receiver's tank circuit as high a Q as possible, and then connect it to a load through a zener diode or other nonlinear device. This will allow the voltage/current of the tuned circuit to rise to a huge level and produce an intense AC field, but without the load interfering. Only after the AC field has reached the appropriate level will we extract any energy and deliver it to the load. [NO, NOT A ZENER! A zener would just act as a series RESISTANCE, dissipate heat, and throw away energy uselessly. Instead, just use a detector diode, and charge up a DC capacitor. 11/1/99]

Two: try using an FM detector circuit to force the receiver to "lock on" to the transmit frequency. If we do this, we could still use immensely high q-factors, but without making our frequency-match adjustments be so sensitive. We could even send out modulated signals (broadband, not narrowband), and still use them to power distant motors. I don't have a solid idea of how FM detectors work, so this might not be straighforward. Might need an active PLL driving a variable capacitor...

Three: once the receiver is oscillating and energy is being transferred, try suddenly changing the voltage of the transmitter. Since the entire system acts like a well-coupled transformer, I suspect that fast changes in transmitter voltage will appear as fast changes at the receiver. Maybe it only takes a single AC cycle for the change to appear. Weird thought: if the transmitter is modulated *faster* than the transmission frequency, would the fast modulation signal appear at the receiver?!!! That would be impossible, since it would violate Shannon and the rules of AM transmission theory. However, the coupled-resonator system more resembles a pair of atoms transferring photons, rather than resembling an RF transmit/receive system. If the device behaves like a quantum-mechanical coherent system, then perhaps we can modulate the transmitter at a faster rate than the carrier frequency! If it worked, that would REALLY be weird, no? Imagine transmitting at the 59Hz earth resonant overtone frequency, then amplitude-modulating the 59Hz carrier at 1 KHz, and having the signal appear at the receiver's resonator! We wouldn't really be transmitting radio energy. The signal would more resemble QM "wavefunction collapses" which propagate throughout the Earth's ionospheric resonant cavity.

Four: 11/1/99 This circuit mimics atomic absorption, and it also should mimic stimulated emission. Once the circuit is oscillating, it's absorbing the incoming waves because of its phase. The phase relationship causes it to couple to the transmitter. If the transmitter was suddenly turned off, then maybe the circuit would not be able to radiate, since without the waves from the transmitter it could not perform the "poynting-flux emission" process. The phenomenon is definitely not linear! So... what happens when the waves from a transmitter should suddenly encounter the fields of a short antenna? If the phase is right, the short antenna should change from an oscillator to an emitter, and begin emitting energy! This is the reverse of the "energy sucking effect," because while "energy suction" can only occur when the short antenna is surrounded by a powerful field, "energy emission" can only occur when the powerful fields around a short antenna are given a traveling-wave field to provide the "stimulation" for stimulated emission to occur. Absorption/emission requires both the trapped fields at the antenna, as well as the traveling fields from a distant transmitter. If my reasoning isn't faulty (it probably is,) this means that it should be possible to build a sort of radio-freq laser, where a distant transmitter causes a small loop-antenna resonator to add its energy to the transmitted wave.

Also, my crackpot side is starting to yammer at me. It's saying that this particular "hole in physics" might seriously damage contemporary Quantum Electrodynamics, and might even show that Einstein's original photoelectric experiment might be interpreted incorrectly. Hey, if Einstein was wrong, does that mean that the Nobel is withdrawn retroactively and awarded to whoever can show rigorously that "energy sucking antennas" are a better explanation for QM phenomena of all kinds? Or does it just mean that my "crackpot half" is just trying to make certain that no conventional scientist will dare to experiment with this stuff! :)

BEWARE: ODDBALL IMPLICATIONS
If EM resonance is extremely important, and if mainstream science doesn't recognize the effects, then god only knows how many unusual phenomena are awaiting exploration by amateurs. The professional explorers with their well-funded troops haven't yet arrived on this particular "new continent." There are still mysteries to be experienced, and it could be many years before the whole thing is paved over with well-traveled highways built through NSF funding.

Ears as antisound-emitters
Whenever any type of "small" receiver seems to be generating an AC field around itself spontaneously, perhaps we should suspect that the receiver is employing the above concepts; that it is actively generating an "anti-signal," and as a result is receiving more wave energy than it's physical size would suggest. This might apply to acoustic systems! If we illuminate a tiny resonant chamber with long-wave sound of the right frequency, standing waves will build up within the chamber, and it will become an emitter. If there is an acoustic analogy for the above antenna physics, the resonant chamber should "bend" the incoming sound towards itself. When the emitted sound superposes with the 3D incoming waves, the wavefronts of incoming sound will be distorted so they they impact on the resonator and thereby increase the area of its "virtual intake orifice". In EM physics this is well known, it's just the Effective Aperture concept.

Might biological evolution have "discovered" this energy-sucking resonator effect in regards to ears? A collection of programmable resonators might work far better than a broadband receiver, even an amplified one.

It turns out that human ears are known to generate their own signals. Much about this is still a mystery, and proposed theories do not match experimental findings. I note that at frequencies below a few KHz, the wavelength of sound is physically larger than the external ear. Perhaps our human hearing system increases its gain by emitting signals which are phase-locked with the incoming sound? This could be easily missed, since the emitted sound would greatly resemble the incoming sound, and could be mistaken as a reflection.

I've heard that human ears have an unexplained property: they can detect signals which are far below any logical noise level. Their detection capability supposedly even exceeds the quantum mechanical noise level. Perhaps ears increase their net received acoustic energy via an "anti-sound" feedback process resembling resonance? Might there be other situations where small acoustic resonators can receive abnormally large amounts of energy? Shades of Ernst Worrel Keely! Hey, maybe I finally have a clear explanation for that "Acoustic Black Hole" phenomenon with the soda straws. And... and... once again the infamous Dr. Thomas Gold is vindicated, and his detractors are shown to be a bit, shall we say, "deaf" to his words.

Side note: How might the inner ear generate sound? Maybe it does not. Maybe it rapidly modulates the stiffness of its parts and therefore uses nonlinear physics to take energy from other frequency bands and use it to power an oscillation at the frequency it wishes to emit. Sort of like using one crystal radio as a "battery" to power the audio amplifier of another crystal radio tuned to a different station. Or like striking a bell with slow blows, while the bell emits a fast oscillation.

Oooo, Very Weird Idea! If ears generate sound only when sound is being received, then perhaps we can detect this. Perhaps it's even under conscious control. When we listen intently to a particular frequency, obviously we're tuning the brain's internal signal processing algorithms. But what if our conscious action actually changes our inner ear mechanics, so that it "sucks energy" at that frequency? If so, then just flood the room with white noise, stick a tiny microphone near your ear, display a realtime spectrogram of the detected noise from the microphone, then try to concentrate on listening to the "high" tones in the noise, and later listen to the "low" tones. Will your ear change (will the spectrogram of the microphone's signal change?) Or, if you try to pick up a constant tone in the noise, will a small absorption band appear in the spectrum of energy near your ear? Easier test: subtract (null out) the noise-generator's signal from the microphone's signal and observe this difference signal. (an electronic delay line would probably be needed.) Now concentrate on listening to the highs or the lows. Will the observed difference-signal change? If so, build a circuit which detects this change and turns on a light bulb. Stick a microphone in your ear, decode the alterations in the sound spectrum, and run your appliances by "thinking" about a tone-sequence!!

If THAT works, then try this next one.

Set up the above system. Listen to the white noise, and imagine that you hear the word "yes". Do it many times. Now play back the recording of the difference signal (or even the raw signal from the microphone.) Can you hear the word "yes" being transmitted by your *EARS*? If so, then you now know how to speak through your ears. This only works when you are listening to white-noise. Imagine that you hear music in the noise, then see if it appears in the recording from the tiny microphone. Perhaps composers can "think music" right onto the tape recorder. "Think aloud" to yourself, and see if your "verbal thoughts" can be heard issuing from your ears as they... leak out of your head? Perhaps one form of telepathy is... acoustic? Can a blind person navigate via a sort of whitenoise-correlation "acoustic radar?"

OK, now hire a schitzophrenic who hears voices, and see if you can record the "voices" via whitenoise environment and ear-canal microphones. Ask the disconnected personality fragments some questions, see if they answer. You've invented the Ousiograph! Now go interview the "Voices" on the Tonight Show ...with or without the cooperation of the victim.

Who'll be the first to explore this silly idea and find out if I'm full of balony?


BALL LIGHTNING
Ball lightning is not yet explained. One of the orthodox explanations is the Storm Maser theory: if thunderstorms emit microwave energy, and if something can somehow focus this energy, then a nitrogen electrical-plasma could feed off the intense microwave flux. The "Energy sucking" theory gives us a second option. Suppose thunderstorms emit weak ELF/VLF e-fields instead of supposedly emitting intense microwaves? If a plasma happened to be resonant with the coherent AC e-field being created by the storm, and if the Q of the resonant plasma system was high, then that plasma would develop an enormous high-frequency e-field around itself. It would suck energy from the fields of the storm and remain "alight." Do nitrogen/oxygen (or carbon?) plasmas have any high-Q resonances in the ELF/VLF spectrum? The plasmas in coronas in the storm clouds might emit the same frequency that a nitrogen plasma-ball would absorb. What about carbon-fiber networks composed of condensing soot? [CORUM & CORUM] Or rather than the plasma-balls extracting energy via pure resonances, do they have self-organization which can communicate with the self-organized lightning plasmas within the thunderstorm and "agree" between themselves to create a "Tesla Power System"? We'd mistake the Ball Lightning's energy source for feeble EM white-noise. The storm becomes the transmitter and the ball-lightning plasma-glob acts as the hi-Q "frequency hopping" receiver.

Do storms create any coherent VLF e-fields? VLF radios certainly don't detect such things, so we normally would assume that such signals don't exist. But hold on! There could be a nearfield effect, where there is no RF radiation, and where e-fields and b-fields aren't directly connected together via the impedance of free space. A loop-antenna in a radio receiver is used with the assumption that incoming EM waves have an E and an M component, and we should just as easily receive the M component as receiving the E. (And so a loop antenna would work just as well as a dipole antenna.) Maybe this is not true of environmental VLF e-fields. Suppose that a storm (or even the entire Earth) has a very strong vertical AC electrostatic field. The loop antennas on VLF radios would not detect it. Horizontal dipoles would not detect it. However, a resonant circuit connected to a suspended wire (and to ground) certainly would. With a high-Q resonant circuit, the antenna might even receive significant power. Call it the "artificial ball-lightning" analogy.


RF TRANSFORMERS: TIGHT COUPLING BETWEEN TWO DISTANT COILS
Iron-core transformers are examples of tight magnetic coupling, and significant power can be transferred between the coils of a 60Hz transformer. Capacitors are similar: they are examples of tight electrostatic coupling. Resonant circuits give us two new options for tightly-coupled power systems: pairs of high-amperage resonant loop-antennas, and pairs of high-voltage resonant dipole antennas. The spacing of each of these must be below 1/4 wavelength for the phenomenon to appear, and the e- or b-field strength must be very high. Now that I'm speaking of this, I know I've seen such things in common use. Air-core transformers in ham-radio antenna tuners and high-power HF and VHF radio transmitters employ this effect. If both sides of an air-core transformer are tuned to the same frequency, then the b-field surrounding the transformer will build up to a very high level, and the throughput of energy will be very high, even though there's no closed iron-ring magnetic circuit, and coupling between the coils is *apparently* very loose. Note that this sort of thing would limit the transmission bandwidth. Good for low-quality AM radio or for transmitted power, but not for broadband fast data.


MECHANICAL "ENERGY SUCTION"
Rick M. points out that mechanical forces might become significant in resonant EM systems. Normal transformers and capacitors certainly do display significant mechanical forces. If a transformer can be made into an induction motor, and if a capacitor can be made into an electrostatic motor, what kind of motor can be built from a loose/tight coupled high-frequency resonant EM device? I have no idea. Perhaps some strange and interesting hobbyist projects are lurking in these particular "undergrowths." Imagine a radio-frequency induction motor built without iron, whose (resonant) stator is at a great distance from the (resonant) rotor, yet the torque between them is still immense. Imagine a high-Q capacitor-based high voltage motor with huge torque, and with all of its parts embedded within plastic (to eliminate the corona problems associated with DC electrostatic motors.) Imagine a carefully-balanced supermagnet that's spinning at 60Hz in a vacuum chamber out in the woods, driven by the feeble environmental 60Hz magnetic field.


ELECTROMAGNETIC PRANKSTERS
An evil thought: if we built a resonant antenna within a 1/4-wave distance of an AM radio tower, we might be able to "suck energy" at such a high rate that we could run motors and light lightbulbs! The resonant antenna might be very small, but it would have an intense e-field (or magnetic field if it was a loop antenna), and would reach out and touch the AM tower electrically. I've heard of people using "inductive coupling" to steal 60Hz AC electrical energy. Resonant energy-theft. The addition of a resonant circuit would vastly increase the ability of a pickup coil to suck in energy from any distant conductors as long as the frequency was fairly low. In physicist-speak, "If the world is already full of Sodium light, build some artificial Sodium atoms as absorbers."

Now I guess I need to go make a high-Q tuned circuit and set it to the same frequency as an AM radio station. Dunk the coil in liquid nitrogen. Maybe I can light up an LED! I know that longwire antennas can do this. I also know that an AM radio, if tuned to a weak station, can be affected when an adjacent unpowered AM radio is tuned to the same station. Untuned inductive pickup coils can receive "inductively coupled" energy if the b-field in the area is strong. Instead, with a small coil which resonates at 60Hz, maybe I can magnetically grab some AC power out of the wiring in my walls? It would be cool to have a wireless lightbulb connected to nothing but a high-value 60Hz inductor and capacitor. Maybe it would work a bit better if I wrap a couple of turns of "transmit loop" around my house and drive it with 10KHZ from my stereo. With thick wire and hi-Q resonance, it wouldn't take much to put many amperes into such a coil. Rats, now I wish I still lived next to a big AM transmitting tower like I did when I was a kid.


L.O.S., THE CREATIVITY DRUG
In conclusion, I must answer the obvious question: is Bill Beaty on drugs or WHAT?!!! No, instead I'm on deadline. I'm staying up all night for many nights in a row while beating my head on this interwoven industrial application interrupt-driven cludgy embedded set of C-code background tasks. Lack of sleep is itself a drug. Not LSD, use LOS! College students at exam time are well aware of this phenomenon. Stay up all night for a few too many nights, and you find that philosophy gains entirely new meaning, your wife starts looking at you funny, you are in danger of following Heinlein/Hubbard/Wilson and attempting to start your own religion... and the shades of Tesla and Feynman start subspace-idly coupling some 'Special Ideas' into your throbbing demented neuronal subprocessor networks.

So what do *YOU* do for fun?

;)

    

More musings...

Bill b article: Light without photons (NEW 9/99)

MORE: some email discussions

REFERENCES:

1.  W. Beaty web-article, "Acoustic Black Hole" phenomenon.

2.  J. F. Sutton and C. C. Spaniol, "The Black Hole Antenna", PROCEEDINGS OF
   THE INTERNATIONAL TESLA SYMPOSIUM, 1992, International Tesla Society

3.  J. F. Sutton and C. C. Spaniol, "An Active Antenna for ELF Magnetic
   Fields", PROCEEDINGS OF THE INTERNATIONAL TESLA SYMPOSIUM, 1990,
   International Tesla Society, 1990

4.  C. F. Bohren, "How can a particle absorb more than the light incident
   on it?", Am J Phys, 51 #4, pp323  Apr 1983

5.  H. Paul and R. Fischer "Light Absorption by a dipole", SOV. PHYS. USP.,
   26(10)  Oct. 1983  pp 923-926

6.  K. Corum and J. Corum, "Fire Balls, Fractals, and Colorado Springs: A
   Rediscovery of Tesla's RF Techniques," PROCEEDINGS OF THE INTERNATIONAL
   TESLA SYMPOSIUM, 1990


Suggested by A. Boswell, regarding small-antenna physics:
Chu, J.Appl.Phys. Dec. 1948
Hansen, Proc.IEEE Feb. 1981.

LINKS

   What Is A Photon? OPN Trends, S1 supplement 2003 and archive.org
   Non-hertz waves in cables
   JCE: creation/absorption of photons
   Valley-sized antenna at Jimcreek
   Realtime Schumann e-field spectrum, and photo of antenna
   Zenneck's EM surface wave
   EM wave applets
   MIT E&M: dipole radiation anim
   Tesla & surface waves
   Sutton's active antenna and "regeneration"
   VLF antenna at Culter Me
   For sale: resonant antennas from Degen, Terk and Select-a-tenna
   Backwards-wave xmssion line
   Resonate coil project
   Crossed-field Antenna
   Gieskieng Antenna (E-to-M 90deg phase shift output)
   BOOK: Causality, EM Induction and Gravitation (Dr. Oleg Jefimenko)
   PHYSLETS: accelerated charge
   Dipole radiation movie
   H. G. Schantz papers (and antenna animations!)

MORE LINKS, somewhat less crackpotty

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  Регистрация / Forum registration
Публикувано от: mzk - 24-04-2016, 12:54 PM - Форум: Форум analogov.com - Без отговори

За регистрация във форума моля пишете мейл на пощата на форума - info (маймунка) analogov (точка) com с отговори на следните въпроси:

- Възможно ли е да разкажете какви са Вашите интереси, в коя точно област от свободната енергия работите най-силно?
- Какви експерименти сте провели и/или имате желание да проведете?
- С каква апаратура разполагате и/или имате необходимост да ползвате?
- Как оценяте Вашата теоретична и практическа подготовка в конкретната сфера? (Например имате ли практика от провеждане на измервания, проектиране и т.н.).
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Эсли Вы хотите присъединиться к нашем форуме, пожалуйста пишите mail на info (at) analogov.com, в котором попробуйте ответить на следующие вопросы:
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- Ваши експерименталные резултаты или будущие планированные опыты?
- Ваше оборудование?
- Ваш опыт и знания в конкретной области интересах(напр. измерения, проктирование и т.д.)?
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If you wish to become a member of analogov.com please send an email to info (at) analogov (type-dot) com answering the following questions:

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  Сайтове
Публикувано от: mzk - 16-04-2016, 09:08 PM - Форум: Военни технологии - Без отговори

http://sila.rg.ru/rubric/vooruzhenie

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  [ВИДЕО] Наблюдение и проследяване в модерните технологии
Публикувано от: mzk - 16-04-2016, 09:00 PM - Форум: Информационна сигурност - Без отговори

https://www.youtube.com/watch?v=JbQeABIoO6A

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  Предизвикване на дъжд
Публикувано от: mzk - 16-04-2016, 06:59 PM - Форум: Екология и икономика, енергийна ефективност и ВЕИ - Без отговори

Цитат:Feasibility study of artificial rainfall system using ion seeding with high voltage source
http://www.sciencedirect.com/science/art...8615000066

A non-linear computational modelling of ions from the ground station for electrifying the atmosphere to make feasibility study of artificial rainfall system is proposed and analyzed.


Цитат:Лекция
(https://www.youtube.com/watch?v=fk8m4esuZ40)

Dutchsinse -- Artificial Atmospheric Ionization - Rain via Electricity

Статия (ARTIFICIAL ATMOSPHERIC IONIZATION: A Potential Window for Weather Modification)

.pdf   88063.pdf (Размер: 332.7 KB / Сваляния: 737)



Цитат:Scientists Create 52 Artificial Rain Storms in Abu Dhabi Desert
http://newsfeed.time.com/2011/01/03/scie...bi-desert/

...put steel lampshade-looking ionizers in the desert to produce charged particles. The negatively charged ions rose with the hot air, attracting dust. Moisture then condensed around the dust and eventually produced a rain cloud. A bunch of rain clouds.

Цитат:China creates 55 billion tons of artificial rain a year—and it plans to quintuple that
http://qz.com/138141/china-creates-55-bi...uple-that/

Цитат:Руски патент WIPO Patent Application WO/2005/006844 
.pdf   WO2005006844A1.pdf (Размер: 990.47 KB / Сваляния: 578)
METHOD FOR BREAKING ANTICYCLONIC CIRCULATION AND DEVICE FOR CARRYING OUT SAID METHOD
http://www.freepatentsonline.com/WO2005006844.html


.pdf   ilap.pdf (Размер: 112.43 KB / Сваляния: 787)

Цитат:http://www.coresor.com/waterandweather/c...nager.html

Clear Sky Manager TM
Based on the ILAP Technology (Influence on the Local Atmospheric Processes), Clear Sky Manager TM, has been developed for managing, at local atmospheric level, humidity density in the sky in order to pursue a wide range of possible objectives: create precipitation, avoid (or create) snow, disperse fog and smog or, generally speaking, conduct any type of atmospheric action that may improve working/living conditions at ground level.

Based on top of the art technology, Clear Sky Manager TM  relies on high-speed ionic generators for initiating and managing upwards/downwards air streams within a given area, up to 100 km diameter.

The system requires the installation on the ground of 5 to 8 ionic generators that are locally distributed in accordance to local ground and meteorological conditions. 

Three main operational modes can be programmed and implemented on the basis of the equipment:

1.  “Rainfall” / “Snowfall”

The “Rainfall” mode is meant for initiating or intensifying atmospheric precipitation within a given area, up to 100 km wide. It may be used for agricultural development (possibly in connection with an irrigation infrastructure) or for the prevention and fighting of forest fires. This mode is typically of use in sunny and dry regions.


The system creates a stable upward air stream that carries with it a great amount of atmospheric moisture. On the way to the upper atmosphere, the air is cooling. The atmospheric moisture is condensed, creating clouds or intensifying already existing ones so that precipitation occurs. 

The upward air stream height and intensity are adjusted according to the desired results by setting up (by local or remote control) the parameters of the ion generator’s working mode.
Full size exercises have been conducted  with success.



Preparation for Rain
The “Snowfall” mode is identical in its essence but is meant for mountain resorts where snow is needed in great quantity for the quality of skying areas or for the safe conduct of winter-sport events.   


2. “No Fog” – “No Smog”

The upward air streams created by Clear Sky Manager TM cause the compensating downward air streams that can be used for enforcing dissipation of clouds and fogs.  

The area under control can expand to 100 km² (10 x 10 km). The specific area to protect may be an airport or a seaport, where traffic congestion can be created in case of heavy fog. Clear Sky Manager TM  guarantees a clear visibility up to a 1,000 m distance, meeting the criteria of fog destruction. 
In regions where industry, traffic or land fires create haze or smog, the same technology is able to clear large portions of cities and countryside, suppressing or diminishing the risks and dangers for the health (and for the traffic) associated with a polluted atmosphere.



Fighting Fog and Smog
3. “Stop Snow” – “Stop Hail” – “ Stop Rain”

The creation of upward warm air streams can be used for building heat walls at the limit of a territory and preventing the incoming snow, hail and rain clouds to enter the protected region. 
One field of application are airports, where snowfalls delay traffic and create sizeable additional expenses for the cleaning and the maintenance of the runways. On a broader scale, it is possible to prevent large agricultural areas from being destroyed by hail.
 
A combination of programmed actions can create clear and sunny skies for important outdoor events in periods of bad or unpredictable weather. This may be valuable for social and sporting events, open air festivals, air shows, etc


Много полезен сайт: https://climateviewer.com/2014/03/26/clo...ification/

Цитат:[Изображение: attachment.php?aid=118]
[Изображение: attachment.php?aid=121]

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Прикачени файлове Миниатюри
           
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  Дупките от Наска (Band of Holes)
Публикувано от: mzk - 16-04-2016, 05:28 PM - Форум: Екология и икономика, енергийна ефективност и ВЕИ - Без отговори

http://www.dailymail.co.uk/sciencetech/a...ystem.html
http://mic.com/articles/140792/mystery-o....v9eDOCLMk

Става въпрос за спираловидно изкопани дупки (кладенци?) в земята, които по последни данни са служели за водоснабдяване.
След анализ на сателитни снимки става ясно, че чрез система от подземни (вентилирани?) тунели се осъществява пренос на вода за селскостопански и други нужди.

Не съм чел достатъчно, за да кажа дали водата се абсорбира по някакъв начин в почвата към изкопаните тунели или става въпрост просто за кладенци и подземни води.


(https://www.youtube.com/watch?v=N14Q-9jpAPM)

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