Steve,
Indeed that paper contradicts the ARRL results and supports the 3dB claim.
In fact it shows closer to 5 dB.
Joel responded to the criticism on his results but that was about 4 years
ago and I can't recall what he said.
In view of that, then true openwire is the way to go outside of the shack.
Inside the shack it is more convenient to run the window line.
Thanks for the link. Hadn't seen that one before and based my opinion
solely on the ARRL results.
73
Rick, DJ0IP
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Steve Hunt
Sent: Monday, July 29, 2013 11:06 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] TT 238C will not tune
A number of points:
1) An "ugly" balun is a poor choice for use at the output of a wide-band
tuner. It has high choking impedance over only a very narrow band of
frequencies, and outside that narrow band the impedance is almost totally
reactive; in some situations that means it can actually increase the CM
current.
2) My 238 manual has a totally ambiguous statement about stringing the dial
pointer. To start the process it says: "Run the inductor to the full
clockwise stop (roller to the rear)". Actually, full clockwise has the
roller to the front!!! Depending on whether you chose to go with "full
clockwise" or "roller to the rear", you could end up with the pointer
showing maximum inductance at zero or at 30.
3) The high attenuation figures for wet ladderline derive from the
experimental work of Wes Stewart N7WS:
http://users.triconet.org/wesandlinda/ladder_line.pdf
The later experimental work by ARRL showed lower attenuation for wet
ladderline, but the experimental method was soundly criticised.
Steve G3TXQ
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