[TenTec] Hi power Ten Tec ant tuner swr drift?

[Steve N4LQ]

The feed impedance of that short antenna is much too low. You are going to 
melt down your tuner. Any tuner will get hot and consume a large percentage 
of your RF power when attempting to match such a low Z. If you are feeding 
it through the balun, you are making the situation even worse due to the 4:1 
ratio. It may be transforming 10 ohms into about 3 ohms! Try bypassing the 
balun and feeding it like an unbalanced antenna ( it is unbalanced anyway). 
Another cure is to raise the Z of the antenna with a loading coil around 
midpoint in the vertical.
Steve N4LQ
----- Original Message ----- 
From: "denton" <denton at oregontrail.net>
To: "Tentec Reflector" <tentec at contesting.com>
Sent: Sunday, November 14, 2004 11:43 AM
Subject: [TenTec] Hi power Ten Tec ant tuner swr drift?


Hi all...
I have recently purchased an old Ten Tec L network ant tuner..the one that 
was in kit form many years ago.
I have noticed that when feeding it to a 22 ft elevated ground plane on 80 
meters (yeah I know, really a mismatch) via 450 ohm twin lead that the swr 
will drift on 80 meters and the 2 kv ceramic caps on the cap switch will get 
really hot...
Will switching the caps to transmitting micas alliviate the problem??
Bad switch??
80 meters on this particular antenna apparently is the only band this occurs 
with this transmatch...my 238A does not exhibit this little problem when 
feeding the same antenna.
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