I don't believe Tom's assertions on loading coil taper
or trap losses are based on "calculations". Yuri
conveniently leaves out these facts so as to support
his transparent (and pathological) dislike of W8JI. If you
look in the Towertalk archives, you will find that there was
a debate several years ago on the efficiency of trapped
antennas. W8JI proceeded to make a series of careful
measurements in his lab. He was even soliciting people to
send him traps for measurement. I believe he presented the
results of these measurements at the Dayton Hamvention
Antenna forum. Likewise, W8JI claims to have made
numerous measurements of the current in loading coils, not
just "calculations" as Yuri describes. In fact, after repeated
prodding from yours truly (on eham.net), Tom described
the details of the current probes he used to make the
measurement and why he felt W9UCW's measurements
were in error. An anonymous poster on eham.net even
claimed to have acheived similar results (no current taper)
in a professional setting. He too described they difficulty
associated with these measurements and the need for
careful current probe design. Others (W9UCW) have
measured a taper. The debate came down to an
argument over measurement technique and whether
certain measurement techniques are susceptible to
"electric field" induced errors. Interestingly enough when
the name calling stopped and the eham.net debate got
down to scientific nitty gritty (current probe designs were
presented), the man who eschew's theory and claims
to be "Mr. Empiricism" (e.g. Yuri) was nowhere to be found.
As usual, Yuri, presents a one-sided look at a two-sided
debate. He seems to think that science is done like politics
- smear your opponent and only tell one-side of the story.
Pathetic!
73 de Mike, W4EF............................
----- Original Message -----
From: <K3BU@aol.com>
To: <towertalk@contesting.com>
Sent: Friday, November 21, 2003 7:11 AM
Subject: Re: [TowerTalk] Trap Resonance
> In a message dated 11/21/03 8:03:12 AM Eastern Standard Time,
> mchilkuri@kasnet.com writes:
> >>I am now left wondering where exactly the trap should dip? Tom suggests
that
> it should NOT be brought to resonance on and around the desired operating
> freq. So, where do I tune the trap? I could place it at 14.2 but 14.2
would
> be my desired operating freq!<<
>
>
> I would not rely on TOM, W8JI "wisdom," tune it to where it gives maximum
> signal and the best performance. Tom is way off and wrong on the subject
of
> current in loading coils on the antenna. He has extensive article on his
web site
> that is completely wrong, there was quite a discussion on eHam.net and
> rec.radio.amateur.antenna newsgroup on this subject and people that
measure things
> concluded that the current is not equal at both ends of the loading coil,
while
> he is still insisting that it is (based on wrong assumptions and
calculations).
> Since the trap is acting as a loading coil, looks like you stumbled on
> another proof that he is wrong and disseminating fallacy (not the first
time). The
> final proof is in the signal strength and what you measure, not what
someone
> "calculates."
> Looks like this business of current distribution in the loading coils has
> also significant impact on traps, which become loading coils at lower
bands and
> knowing what is really happening will help to optimize them for better
> efficiency. More info is on my web page
> http://www.k3bu.us/loadingcoils.htm
>
> 73 & GL
>
> Yuri, K3BU
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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