Steve,
Well, I'm not sure if TLW is exactly on or not, but I'm pretty comfortable
with our technique. When we're talking differences of 0.1 dB, not sure if
the exact value is too critical for the usual HF amateur.
Bob and I took careful data, rematched with every new set of data to
compensate for any Zo differences and used good, commercially calibrated
gear to take the data.
Regards, Joel Hallas, W1ZR, BSEE, MSEE
Westport, CT
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Steve Hunt
Sent: Thursday, January 26, 2012 5:06 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals
Rick,
When W1ZR's article appeared in the November 2009 QST it was *very*
controversial. Here's an example of the typical debate it engendered:
http://www.eham.net/ehamforum/smf/index.php?topic=44059.0
In that QST article Joel states that the loss measurements he made on
dry line "agreed with TLW predictions within a few tenths of a dB".
Given that a simple calculation involving Ohms Law will tell you that
the TLW predictions are wrong by a large margin, that must cast serious
doubt on his measurement technique.
73,
Steve G3TXQ
On 26/01/2012 21:31, Rick - DJ0IP / NJ0IP wrote:
> We were speaking about using this transmission line at HF frequencies.
> 30 MHz is the highest frequency but for the vast majority of operations
(on
> the air time), you could even say 21 MHz is the upper frequency limit.
>
> The study in that paper was showing 50 MHz and above.
> It appeared to get rapidly worse as the frequency rose.
> Can we not assume that it gets rapidly better at lower frequencies?
> If so, then Joel's test results could be accurate.
>
> If a non engineer measures losses on a line, then drags it in the mud and
> measures again, and gets trivial differences in the results, shall we
> discard his results just because he's not an engineer?
>
> L.B. Cebik? As I recall he was not an HF engineer, yet we (or I) hold his
> writings to be some of the best in existence.
>
> To be fair to Joel, we should at least read the article, see what he
> measured and how he measured and then criticize his results if something
is
> foul. I don't think it's fair to criticize the paper based on what kind
of
> Engineer wrote it.
> It wasn't really rocket science he was performing.
> It was simple tests that any good ham could perform.
> We just never took the time to do it.
>
> Unfortunately when I moved from the states back to Germany, I threw out
all
> of my magazines so I no longer have the article. Maybe someone else here
> does and can recap what Joel reported. THEN we can beat it to death.
>
> 73
> Rick
>
>
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