[Amps] Ten-Tec Centurion

[Bill Turner]

On Wed, 10 Nov 2004 15:16:22 -0800, Georgens, Tom wrote:

>I have a Centurion at my contest station in Barbados that works flawlessly
>on 10-80 but will arc on 160.  It is tuned into a resonant antenna with a
>reasonable SWR.
>
>On 160, the amp will occasionally arc immediately on key down.  If it does
>not arc immediately, it will not arc if the key is held down.  Also, when it
>does not arc, it tunes smoothly and at the predicted settings.  All of the
>arcing is in the Tune cap and is not always in the same place.

_________________________________________________________

I had an amplifier (not a Ten-Tec) which exhibited similar behavior
once, and the problem was a damaged tune capacitor.  Once a capacitor
has arced, minute pits develop on the plates and it becomes much more
prone to arcing again.  The pits are ragged and increase the tendency
for corona which is a precursor to arcing.

As a test, rotate the tune capacitor 180 degrees so that the
capacitance is the same but a different plate area is exposed.  See if
the arc goes away.  This is not a completely definitive test because
even after rotation the same arced area may be present or not, but if
the arcing does stop, you have your answer.

In my case, I replaced the tune capacitor but a careful disassembly
and polishing of the plates would probably have cured it.  This is not
a job for the faint of heart however, because getting the thing
reassembled correctly is rather tedious.

--
Bill W6WRT