KPA500 Problems

Mike VE3YF


I am having problems to get my KPA500 to key. The KAT500 keys (Completes the tune cycle) but can't get the KPA500 to key.

I have taken the Aux cable from the K3 and moved it up to the KPA500 and still won't key. I move it back to the KAT500 and the KAT500 keys up fine but not the KPA500.

I have been doing some reading here and there and have eliminated a few things.

Digout1 is Off
Cover interlock for the KPA500 is ok.
Aux cable works on the tuner so I am presuming it is good

HV is at 75.1 and when I key the K3, that voltage doesn't move
When I key the amp, I get 0 current
No faults appear.

The K3 and the KPA500 are talking to each other, I can do band changes from the KPA500, etc

When I key the K3, (I have the KAT500 in MAN and Antenna 2 is hooked into a dummy load).
the SWR on the KAT500 goes to 1.2, and on the KPA500 in Operate, the Far left green LEDS on the
Power and SWR bargraphs light up, and the PWR readout is 25w both on the K3 and KPA500.

I have even taken the Aux cable off the KPA500 and tried putting a phono cable on the PA Key jack and shorting out the connector still doesn't key the KPA.

I am quite sure others have had this problem before. But I'm at a loss. The K3 can talk to both the KAT and KPA and the KPA can talk to the K3.

Any help would be greatly appreciated.


73 De Mike

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