KPA100 oscillation -- NOT fixed

[Vic K2VCO]

I recently had the problem of the KPA100 oscillating on 7 MHz when
connected to a particular (well matched and bead-choked) antenna with
the KAT100 in line.  This happened with the improved shield and all KPA
modifications installed prior to the 10/26/06 upgrade.

I installed the 10/26/06 upgrade and the problem went away.  However,
now I have a new problem:  on 21 MHz, there is an intermittent
oscillation when running 100w output.  It manifests itself as a loud
'bzzzat' that's sometimes heard when the rig switches to receive,
associated with lots of LEDs on the KAT100.  Dropping power to 70W seems
to prevent it.

In the immortal words of General Halftrack, "Now What?"
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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[Bill Coleman-2]

On Nov 19, 2006, at 12:25 PM, Vic K2VCO wrote:

> However, now I have a new problem:  on 21 MHz, there is an  
> intermittent oscillation when running 100w output.  It manifests  
> itself as a loud 'bzzzat' that's sometimes heard when the rig  
> switches to receive, associated with lots of LEDs on the KAT100.  
> Dropping power to 70W seems to prevent it.

Are you sure your antenna system isn't arcing? If you have an SWR  
shift under power, that's usually a good sign of an arc.

Bill Coleman, AA4LR, PP-ASEL        Mail: [hidden email]
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901

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