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

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 a
semi-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