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#1
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true or... ?
"-.-. --.-" ha scritto nel messaggio ... I thanks people that until now reply to my post. It's quite clear for me, an Richard and Dave wrote, the true radiating points of an EH antenna, basically the feedline an also imho via groundwave with the grounding system, especially on lower frequencies. What i'm asking is not a *complete* explaining of Maxwell equations in few posts, and why in this specific case can be right or wrong the paper.. just from the guru of this ng a simple "yes, he wrote in the paper a right interpretation of Maxwell equation and, in theory, the thing can work" or a "no, he's worse than a 1st april fool". Like the precedent post on underground antennas systems, i'm just curious and happy if someone *demostrate* me that a strange antenna have a incredible efficiency. But the demostration must be in a understandable way for me, and if i don't understand, i ask to who can understand and had the patience to explain. Sorry, btw, for grammar & language errors. 73, -.-. --.- |
#2
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On Tue, 1 Sep 2009 00:23:31 +0200, "-.-. --.-" wrote:
Like the precedent post on underground antennas systems, i'm just curious and happy if someone *demostrate* me that a strange antenna have a incredible efficiency. Hi OM, Demonstrate is not possible. The antenna radiation is not correctly described. Consider: a commercial AM quarterwave, vertical antenna is probably 95% to 99% efficient. To have an incredible efficiency would add only 4% more to a very simple design that has been around for 100 years. +0.2dB or less is not incredible efficiency. You cannot hear 0.2dB difference in sound, you cannot measure 0.2dB RF difference except with great difficulty. 73's Richard Clark, KB7QHC |
#3
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"Richard Clark" ha scritto nel messaggio ... Consider: a commercial AM quarterwave, vertical antenna is probably 95% to 99% efficient. To have an incredible efficiency would add only 4% more to a very simple design that has been around for 100 years. +0.2dB or less is not incredible efficiency. You cannot hear 0.2dB difference in sound, you cannot measure 0.2dB RF difference except with great difficulty. 73's Richard Clark, KB7QHC Thanks for reply, Richard. Take also into account that, although i don't know much mathematic, i don't have any doubt that is impossible that this kind of antenna can have a great or also medium efficiency. Considering your 1/4 wave AM broadcast antenna example, is not an accident that nor military nor broadcast installations used in the past a type of antenna like the EH/HZ... .... and military brains have knowledges that we in the "civilian" world can use maybe after 20-30 years. And, if this really works, one don't waste time writing PDF. He start working in radio with this antenna, and if the antenna is *really* what he claim, he will be in a very short time a rich man. -.-. --.- |
#4
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true or... ?
"-.-. --.-" wrote in message ... "Richard Clark" ha scritto nel messaggio ... Consider: a commercial AM quarterwave, vertical antenna is probably 95% to 99% efficient. To have an incredible efficiency would add only 4% more to a very simple design that has been around for 100 years. +0.2dB or less is not incredible efficiency. You cannot hear 0.2dB difference in sound, you cannot measure 0.2dB RF difference except with great difficulty. 73's Richard Clark, KB7QHC Thanks for reply, Richard. Take also into account that, although i don't know much mathematic, i don't have any doubt that is impossible that this kind of antenna can have a great or also medium efficiency. Considering your 1/4 wave AM broadcast antenna example, is not an accident that nor military nor broadcast installations used in the past a type of antenna like the EH/HZ... ... and military brains have knowledges that we in the "civilian" world can use maybe after 20-30 years. .... if the first 'nor' should be interpreted as 'neither' then I'd agree. In the UK, 5/8 wavelength vertical radiators have been popular for AM radio broadcasting, singly (e.g. used for some BBC services) and in arrays (for commercial radio, eg. Saffron Green, north London) usually with _very_ extensive earth mats. The Isle of Man International Broadcasting company made a big deal about ten years ago about their intention to use a CFA for broadcasting on 279 kHz, initially from the island, and latterly from a modified oil rig in IOM water (e.g. http://www2.hard-core-dx.com/archive...msg01127.html). However, this still isn't on the air so one may speculate. Chris |
#5
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"christofire" ha scritto nel messaggio ... ... if the first 'nor' should be interpreted as 'neither' then I'd agree. neither, neither just the result of the last minutes of a very busy week with 2 of my radius servers going down for mysql accounting DB flops. Some flops for me writing in english, too 73, -.-. --.- |
#6
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On Fri, 4 Sep 2009 19:03:02 +0200, "-.-. --.-" wrote:
Thanks for reply, Richard. Take also into account that, although i don't know much mathematic, i don't have any doubt that is impossible that this kind of antenna can have a great or also medium efficiency. Hi OM, Efficiency in percent (%) is simple math: 100 * PowerOut/PowerIn In decibels, I won't show the math, I will give some example: 100% is 0dB 95% is -0.22dB 90% is -0.46dB 80% is -0.97dB 50% is -3dB 10% is -10dB Look at your S-Meter. If any station added 5% efficiency, going from 95% to 100%, then your S-Meter would shift 0.22dB. The needle of your S-Meter is probably more than 1dB thick when you look at it. The needle would then move 1/5th of its thickness when a station adds 5% efficiency. Considering your 1/4 wave AM broadcast antenna example, is not an accident that nor military nor broadcast installations used in the past a type of antenna like the EH/HZ... ... and military brains have knowledges that we in the "civilian" world can use maybe after 20-30 years. I have been in the military - antennas work the same there too. I was a teacher of RF Systems (LF/MF/HF/VHF/UHF/SHF). There is no magic knowledge hidden by the government. And, if this really works, one don't waste time writing PDF. He start working in radio with this antenna, and if the antenna is *really* what he claim, he will be in a very short time a rich man. A very short time needs to be defined. This "antenna" has been around for a long time and no one has gotten rich (and the buyers have lost money, time, and signal). Anyone can write a useless PDF. Anyone can get a useless patent too. I have observed patent holders who post here that have forgotten their own patent numbers, their own patent claims, their own URLs, their own email addresses, and their own theory. Talk about a waste of time, but it is wasted with the vigor of a seven year old. It would seem that wasting time, money, and signal power was equivalent to earning a PhD in Einsteinomics and advanced Gaussology. 73's Richard Clark, KB7QHC |
#7
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"Richard Clark" ha scritto nel messaggio ... Hi OM, Efficiency in percent (%) is simple math: 100 * PowerOut/PowerIn In decibels, I won't show the math, I will give some example: 100% is 0dB 95% is -0.22dB 90% is -0.46dB 80% is -0.97dB 50% is -3dB 10% is -10dB Look at your S-Meter. If any station added 5% efficiency, going from 95% to 100%, then your S-Meter would shift 0.22dB. The needle of your S-Meter is probably more than 1dB thick when you look at it. The needle would then move 1/5th of its thickness when a station adds 5% efficiency. Straight and clear. Well, maybe my knowledge of physics and mathematic can go a bit far, including understand e.g. ground losses, path loss in free space, takeoff angle, feed point impedance and other silly things regarding antenna world but sorry, Maxwell equations are a bit harder for me I have been in the military - antennas work the same there too. I was a teacher of RF Systems (LF/MF/HF/VHF/UHF/SHF). There is no magic knowledge hidden by the government. Well, i'm ever a optimistic mind... i just think that maybe tomorrow i can use something better antenna thanks to MIL research ... like a trick to build a 160m yagi in the same space of a 40 m yagi of course, just joking... OTH radar DUGA-3 in Prypiat, ex USSR now Ukraine, is a good example for me, MIL also need big antenna system. Anyone can write a useless PDF. Anyone can get a useless patent too. I have observed patent holders who post here that have forgotten their own patent numbers, their own patent claims, their own URLs, their own email addresses, and their own theory. Talk about a waste of time, but it is wasted with the vigor of a seven year old. It would seem that wasting time, money, and signal power was equivalent to earning a PhD in Einsteinomics and advanced Gaussology. Well, let say that *today* is more obvious and easy that this total waste happen. Globalization and the internet make very easy for timewasters to get a large public for the things they are saying/writing/claiming. And the same, in a reverse way, happens to the skilled people, that have occasions to read tons of wrong assertions on the internet. Many years ago the worst case is to listen to timewasters on a local repeater or on a 40/75/80 meters net. When i don't understand something, the first thing i do is ask, ask and ever ask. Unfortunately, today is easy in the same manner both turning on a computer and turning on a radio to communicate with other people. Unless you don't have a wireless connection, the computer have as a bonus that don't need any kind of antenna. Thanks for your time, -.-. --.-, Cristiano, Italy. |
#8
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On Sat, 5 Sep 2009 01:14:36 +0200, "-.-. --.-" wrote:
Straight and clear. Well, maybe my knowledge of physics and mathematic can go a bit far, including understand e.g. ground losses, path loss in free space, takeoff angle, feed point impedance and other silly things regarding antenna world but sorry, Maxwell equations are a bit harder for me Hi Cristiano, The only people that rely on things like Maxwell's equations, or Gauss' Law are those who don't know the math. You don't need that math to discuss 99% of the art of design. That math might be mentioned, but whoever is trying to use it as their sole point of discussion is someone who is lost. I have been in the military - antennas work the same there too. I was a teacher of RF Systems (LF/MF/HF/VHF/UHF/SHF). There is no magic knowledge hidden by the government. Well, i'm ever a optimistic mind... i just think that maybe tomorrow i can use something better antenna thanks to MIL research ... like a trick to build a 160m yagi in the same space of a 40 m yagi of course, just joking... OTH radar DUGA-3 in Prypiat, ex USSR now Ukraine, is a good example for me, MIL also need big antenna system. Military designs and commercial designs did lead the way for practical antennas .... 70 years ago. If you want to build an 160M version of a RADAR antenna you might get more argument from your neighbors than you will find here. That huge antenna will show every characteristic at 160M as it does at SHF, but you better be pointed in the right direction. 73's Richard Clark, KB7QHC |
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