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The following is Ted Hart's response to me:
----- Original Message ----- From: Ted To: Walter Maxwell Cc: Bill Ronay Sent: Tuesday, January 13, 2004 5:50 PM Subject: EH Antenna Hi Walter, Every one is entitled to their opinion - but accurate test data is irrefutable. Comments to your comments are in your text below- - - - Ted ----- Original Message ----- From: Walter Maxwell To: Ted Sent: Tuesday, January 13, 2004 3:20 PM Subject: EH Antenna Hello Ted, Thank you for your response to my note to Bill. Ted, I'm sorry to have rained on your parade, but I have not seen any proof that your antenna outperforms any Hertzian antenna as you claim. As I read in the 'Article' appearing on your web site, you are claiming that when your 'EH' is at 1/4 wl above ground it has a 2.25 dB gain over a standard 1/4 wl vertical. Ted: TRUE I have reviewed very carefully the engineering document prepared by the broadcast consulting firm of Graham Brock, Inc., who performed extensive field strength measurements on your EH antenna at experimental WK4XVQ in Eatonton, GA, operating on 1520 KHz. To summarize very briefly, their report first shows an average of approximately 1.1 dB Ted: (0.84) dB less power radiated than the reference standard antenna. Second, it is noted that the test antenna was atop a 90-foot tower. Ted: The tower was 90 feet, the EH Antenna was below that. The EH Antenna was at was coupled to the standard WKVQ tower during the measurements, which is very likely the reason the azimuthal plot of your EH antenna is scalloped rather than circular. Ted: Pattern distortion was due to a power line I'm sure you're aware that nearby objects that are resonant at the measurement frequency will distort the readings and thus distort the resulting data. What was done at the feedpoint of the WKVQ antenna to eliminate the possibility of its becoming a part of the antenna system? Were the input terminals shorted? Left open? Ted: Open Were any measurements made under both of these conditions to determine whether the the WKVQ antenna was performing as a parasitic radiator? From the measurements performed by the Graham Brock engineers the resulting data shows evidence that rather than achieving gain over a standard antenna, the EH antenna performs less well than the standard antenna. Ted: Read the rest of the story - the center of the EH Antenna was at 0.1 wavelengths above gound - if it were raised to 1/4 wavlength then it would be what I claim, 2.25 dB gain over a standard 1/4 wl vertical. At this point I'd like to repeat what I stated earlier concerning the concept of your EH antenna's performance resulting from changing the time relationship between the E and H fields to increase the radiation. What I stated earlier is that the development of the continuous alternating E and H fields cannot be changed in any way--not by changing the phase of the source current, or by any other means. The laws set forth by electromagnetic theory are immutable. And I also repeat--the antenna you believe to be prforming in a new manner is simply a shortened, inductively loaded Hertzian antenna performing in its conventional manner. Ted: You are wrong. If you were correct, the effective radiation resistance would be a fraction of an ohm, not a much much higher resistance as indicated by the measured bandwidth. I believe you should consider the following academic treatment that should help convince you that you cannot get additional power for nothing. Assume a 1/4 wl vertical antenna with zero ohmic resistance working over perfect ground. In this condition the only resistance in the system is radiation resistance, and ALL power delivered to the antenna is radiated. Consider now an imaginary hemisphere surrounding the antenna. When power P is delivered to the antenna and all of the power radiated is then integrated over the entire hemisphere, the integrated power will equal power P exactly. Now, because all of the power delivered to the antenna is radiated, any increase in radiated power due to some change in the configuration of the antenna is impossible. Therefore, this constitutes proof that your claim of gain with the EH configuration is invalid. Ted: Again, you do not present a valid argument. What you say is true, but not germain to the issue. Consider antenna pattern gain, not total radiated power - - - The purpose of an AM Broadcast station is to provide maximum signal to the listener on the ground and reduce skywave as much as possible. You say you have three patents on the EH. In so doing you have accomplished what many before you have accomplished--outwitting the patent examiner who lacked sufficient knowledge of the subject to recognize an invalid concept in the patent application, and granted the patent. You may not have been aware that hundreds of patents have been declared invalid for this specific reason. Ted: But one criteria is proof of performance - and I presented that to the examiner. I have no doubt that you honestly believe that your EH concept is correct and valid, and that your antenna is performing within that concept. However, now that you are made aware of the invalidity of the concept, and if you continue to manufacture and sell your antenna as advertised to perform as you say it does, then you must also come to believe you would be misleading the public. In this litigious society don't be surprised if someday an attorney hands you a paper claiming fraud. I would not like to see that happen. Ted: No one can claim fraud if the antenna does what I say it does. Finally, if you still choose to believe my comments are incorrect, then I would suggest you consult with other RF engineers to obtain their expert opinion, many of whom have far greater intellect on this subject than I. Ted: I agree that you do not have a complete understanding of antennas. You can find some eminently qualified engineers in the news group rraa (rec.radio.amateur.antenna) by simply going to 'find' and inserting 'EH'. Cordially, Walt, W2DU Ted: Please learn to read before you criticize - every thing I say about the EH Antenna is valid. Ted: Please do not respond - there is nothing you say that is valid and I do not wish to waste my time trying to teach you something because you have such a closed mind. Ted Walt here now: It's past midnight now, but I'll have a short response to Ted's above comments tomorrow. Walt, W2DU |
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#2
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On Wed, 14 Jan 2004 04:19:32 GMT, Walter Maxwell wrote:
Ted: You are wrong. If you were correct, the effective radiation resistance would be a fraction of an ohm, not a much much higher resistance as indicated by the measured bandwidth. The "measured bandwidth" reveals the proximity of earth in series with a small radiation resistance. Lower the eh to ground level and you would have a multiband antenna? (Quick, print this on the side of the box and double the price!) 73's Richard Clark, KB7QHC |
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#3
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Walter Maxwell wrote:
The following is Ted Hart's response to me: ----- Original Message ----- From: Ted To: Walter Maxwell Cc: Bill Ronay Sent: Tuesday, January 13, 2004 5:50 PM Subject: EH Antenna Hi Walter, Every one is entitled to their opinion - but accurate test data is irrefutable. Boy, he finally got something right...Yes, accurate tests results can tell a lot. *IF* we get ever get to see any. Testing a non-decoupled very small antenna that is mounted to a metal 90 foot tall tower is not accurate test data. It is a joke of immense proportion. The BC tower in close proximity bothers me less than this. He is not testing an E/H antenna. He is testing a 90 ft tower and feedline, being the problem of common mode currents on the feedline are severe. Even he admits that "rf in the shack" can be a severe problem with these antennas. But!!! He advocates NOT using any form of feedline decoupling. It's no wonder, being that will effectively kill the radiation from his main radiator. Which is the feedline and tower. Someone, maybe from "Antennex", tested an E/H antenna fed directly from the base of the antenna, with NO feedline, and NO tower. Needless to say, the performance was earthshaking. Ormaybe we should say it's non-performance....But when you have plans to unload these buggers for appx 40k+ apiece, I guess the motivation for *creative* testing really kicks in. Accurate testing goes out the back window. An accurate test result will not fit the program. The prince becomes an ugly wart infested fraug. http://search.yahoo.com/search?x=wrt...eb-t&n=20&fl=0 http://www.google.com/search?hl=en&i...=Google+Search for some more reading. When he does a controlled test where the antenna is mounted on a non-conducting tower or mast, and feeds the antenna directly at the feedpoint using NO feedline, or at the least, a very well decoupled feedline, then you can call it an accurate test. What he offers now is an insult to most peoples intelligence. It's an insult to mine, and I'm just a run of the mill dummy compared to many others on here. I suspect most *real* broadcast engineers snicker like small school children when they discuss the merits of the E/H antenna behind closed doors. MK -- http://web.wt.net/~nm5k |
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#4
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On Thu, 15 Jan 2004 03:52:11 -0600, Mark Keith wrote:
Boy, he finally got something right...Yes, accurate tests results can tell a lot. *IF* we get ever get to see any. Hi Mark, His own data shows quite clearly that the eh antenna, 10 miles out, is more than 30dB down from the nearby standard quarterwave it is supposed to replace. His own data shows that at 1 mile out, the eh is still underperforming. There is a basic disconnect between what is claimed, and what the data clearly shows as a burnt resistor. More accuracy may improve the -30dB to -30.1dB but would hardly make things any better - or any worse. 73's Richard Clark, KB7QHC |
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#5
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Richard Clark wrote:
On Thu, 15 Jan 2004 03:52:11 -0600, Mark Keith wrote: Boy, he finally got something right...Yes, accurate tests results can tell a lot. *IF* we get ever get to see any. Hi Mark, His own data shows quite clearly that the eh antenna, 10 miles out, is more than 30dB down from the nearby standard quarterwave it is supposed to replace. His own data shows that at 1 mile out, the eh is still underperforming. Yea, But it should be even uglier if he does away with the tower and feedline. Real ugly in fact.I doubt we will see any tests done without a metal support, or radiating feedline. "IE: the E/H antenna tested by itself, on it's own merits". Or at least sponsored by that bunch. I wish I could remember who tried it without the tower and feedline...Might be in google archives...It was so ugly, it stunk up the place. MK-- http://web.wt.net/~nm5k |
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#6
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Mark Keith wrote:
He is not testing an E/H antenna. He is testing a 90 ft tower and feedline, being the problem of common mode currents on the feedline are severe. I might add, he is testing a 90 ft tower fed in a less than optimum manner also...I could shunt feed a 90 ft tower like a normal person would, and beat his setup any day I bet. If I top loaded the tower with loading wires or a hat, Look out Mr. E/H ...It ain't gonna be pretty. I wouldn't have the lossy coil in the "E/H" apparatus to contend with for one thing. So I bet his test results of feeding the E/H ant-90 ft tower/feedline combo, most likely are inferior to feeding a 90 ft tower in a conventional manner, assuming equal ground losses. Note how the comparison B/C antenna compares overall... So lets see...The price ofa 90 ft tower plus wire for 120 radials, or a $40k+ E/H antenna plus the 90 ft tower as support. He says you don't really need radials...*snicker*...The E/H antenna setup will most likely be the poorer performer of the two setups. Dunno, I know which line I'll be in.. And I can tell you I won't have to drive to GA to pick it up...:/ MK -- http://web.wt.net/~nm5k |
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#7
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On Thu, 15 Jan 2004 04:43:59 -0600, Mark Keith wrote:
Mark Keith wrote: He is not testing an E/H antenna. He is testing a 90 ft tower and feedline, being the problem of common mode currents on the feedline are severe. Hello Mark, Perhaps I'm not perceiving your position on the EH correctly, but from your discussions above and in your previous post, my perception is that you believe the EH exists and can be tested, and your problem is only with the test procedure. Mark, my position is that the EH does not and cannot exist in the manner Hart specifies, because there is no way that the E and H fields can exist in time phase--the change in each field generates the other sequentially. Hart seems to be unaware of this fundamental fact, and also seems to be unaware that no power can be delivered with current lagging voltage by 90 degrees unless there is an opposite reactance to move the phase away from 90. Since power IS delivered to the so called EH, the lagging current due to the series inductance must simply be compensating for the capacative reactance in a conventional shorter-than-resonant antenna, thus bringing it to resonance. I'm saying there is no such device as an 'EH' antenna. Walt, W2DU |
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#8
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Walter Maxwell wrote in message
I'm saying there is no such device as an 'EH' antenna. Oh, I agree totally. I consider it no different than any other small loaded antenna stuck on top of a tower. Well, except that it's less efficient than many... But even noting that, to me, the test is asemi-sham also. Not really due to problems from the test consultants, but from including an obviously radiating structure and feedline with this antenna during the test. This *requires* the same height tower "90 ft" to be included under the antenna in order to match the results they show. Dunno, they may have done a decent job of testing, but someone in the office should have noted that the obviously radiating tower and feedline would skew the results. They use no decoupling of the feedlines. In their info, they never state that a tower is a required section of this antenna. They consider it only a support, and they claim it or the feedline doesn't radiate. If I had been the test consultant, I would have demanded the antenna be placed on a non metallic structure, and to either have the transmitter at the feedpoint, or use a well decoupled feedline. If they refused, I would have declined the job, being I would have realized the results would be not a result of the small antenna, but also include the radiating tower and feedline. And thus be pretty much of a joke if you really want to test the antenna alone on it's own merits. And to add insult to injury, the comparison low tech B/C tower won the contest. I have seen notes that he states these antennas could be roof mounted. I wonder what he will use as the *main* radiator in this case, if there is no 90ft tower on the roof. I guess the radiation from the feedline will have to do the job...Which could be partly indoors, and could even be shielded by metal in places. Hot shack RF wise too I bet. Most real world E/H tests mention this problem. What a mess... :/ I don't see broadcast stations lining up for this system. Only a few gullable hams... MK |
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