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Happy New Year to you, too, Rick.
To anyone who believes the W5QJR EH concept is valid. I just now received a request from Rick Lutzinger, KD6ZR, asking for my opinion on the validity of the EH concept W5QJR touts as his invention in his website at www.eh-antenna.com. I went back and reviewed the posts on this thread posted during the last week of September 2003. Surprisingly, I didn't find anyone who disagreed with the concept. All I found there were disgreements with the claims for gain and realistic claims that this antenna could not even radiate as well as a conventional antenna. With this I agree. The following text contains my reply to Rick: Hi Rick, I didn't have the opportunity to refer to Hart's fiasco until day before yesterday. He appears to still be in the business of publishing proofs of his limited knowledge of antenna and transmission line principles. Unfortunately, he appears to believe he's found something new in his 'EH' concept. On the contrary, 'his' antenna still performs as a Hertz, and his limited knowledge has misled him believe he has something different. So let's examine the situation. Let's begin with a traditional resonant 1/4 wave vertical antenna over perfect ground fed with a 50-ohm coax matched to a source delivering all of its available power--signifying a conjugate match. Now let's add some inductive reactance between the coax and the antenna. There is no longer a conjugate match, the current lags the voltage, the power factor is no longer 100%, and the delivery of power is reduced proportionately. If we continue to increase the inductance until the current lags voltage by 90 degrees the power factor is zero, because cos 90 = 0. In this case the only power delivered by the source is that dissipated in the inherent loss of the inductance. The reactive power contained in the inductance is reflected back to the source resulting in a mismatch that prevents any further delivery of power other than that required to supply the power dissipated in the loss resistance of the inductance. In this condition no power will be delivered to the antenna. However, if a capacitor is inserted in series with the inductor having the same but negative value of reactance as the inductor, we know that the total reactance now is zero, the conjugate match is restored, and the power delivery returns to normal. On the other hand, Hart is applying the 90-degree phase lag to a very short antenna, whose input impedance is capacitive. As the series inductance is increased to where its reactance equals the negative reactance of the antenna capacitance, we have the conventional loading and matching of an antenna that is shorter than that of resonance. Now if Hart is able to obtain an input to the antenna that approaches an impedance match allowing power to be delivered into the antenna, the capacitive reactance of his short antenna is simply compensating for the series inductance he believes produces current that lags voltage by 90 degrees. Tain't so. He is simply feeding a traditionally matched short Hertzian antenna. Further, voltage applied to Hart's 'EH' antenna results in antenna current flowing in exactly the same manner as in any antenna, and the E and H fields are formed and are related to each other in the same chronological manner as in any antenna. The natural laws of electromagnetic theory govern the field development and there is nothing anyone can do to violate those laws developed by James Clerk Maxwell in the 1800s--they have been proven immutable for more than 120 years. So how come the respondents rave about how terrific their 'EH' antennas work? It's only because they fail to understand what is really happening--there is no change in the chronological relationship between the E and H fields, as Hart has misled them to believe, they are simply using a shortened loaded antenna in the traditional manner. Hope you find this of value, Rick 73, Walt PS--Please note in the References section of Reflections that an asterisk preceding a name indicates that that reference contains erroneous and misleading information. Now take a peek at my Reference 100. The material in that reference proves that that writer even then didn't didn't have a clue concerning transmission line theory. Note also the date: March 1969--things don't seem to change very much. Walt Maxwell, W2DU |
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