[Elecraft] Fw: KPA 100

[Arthur Lewis]

----- Original Message ----- 
From: Arthur Lewis 
To: lists at subich.com 
Sent: Wednesday, December 30, 2009 11:02 AM
Subject: KPA 100


I have a KPA100 with a problem. I have two K2/100 and if I exchange the KPA100s the rig works fine. Therefore the problem is not with the K2. The problem KPA100 was built in 2000 and was a good working unit until recently. Both of these units are top cover KPA100s. 

Problem:
It seems to draw Hi Cur as soon as I start bringing up the power level and the output goes to something above 10 watts. After the relay clicks on the KPA100 the output on an external watt meter goes above 100 watts and the SWR on the external watt meter goes high.  The power adjustment has little effect and the rig is drawing about 22 amps.  

Again if I exchange the KPA100 with one that is working properly, everything works normal. The rig draws about 13 amps at full power with the good KPA100 and at the low end, before the relay clicks, has full adustment and low current draw. The K2 seems to be working well on receive.

Looking for seggestions. Is this self oscillation or perhaps a LPF problem?

Art WA8VSJ