[Top] [All Lists]

Re: [TenTec] Suggestions please

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] Suggestions please
From: "Paul Christensen" <w9ac@arrl.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sun, 9 Jan 2011 16:31:25 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
> For example, when used in the multiband doublet application 200ft of
> Wireman 553 has about 2.6dB of loss at 28MHz. When wet, that figure
> rises to 9.3dB, based on the work of Wes Stewart N7WS.

And the reason I've been using homebrewed open 600-ohm line -- using the 276 
log formula  :-)

The line uses E.F. Johnson glazed ceramic spreaders spaced every 18-inches. 
Total of roughly 50 ft. of line between a 130 ft flat-top dipole to a 
ground-mounted motorized symmetrical balanced tuner.   When QRT, the 
balanced line is automatically disconnected from the tuner with a pair of 
Jennings vacuum switches to form a quasi "knife switch."  LMR-400 between 
the ATU and shack.  The open feeder length represents a reasonable end-Z 
compromise on all bands from 80m-10m and remains under 1,000 ohms and over 
50 ohms at the tuner terminals at all times.   50-ohm VSWR  never changes, 
wet or dry.  Next time the line comes down, a re-application of Rain-X is 
needed on the glazing.   ATU details on my QRZ.com page.

Been tempted to replace the Johnson spreaders with Delrin but I doubt 
there's much difference in total dielectric loss with such a short run of 


Paul, W9AC

TenTec mailing list

<Prev in Thread] Current Thread [Next in Thread>