[Elecraft] KPA500 delay in amplification

[Travis Brown]

Guys,

   I am using a K3 with a KPA500 and KAT500.  Everything was working well until I tried sat down at the station this morning.  When I key up, the KPA500 doesn't amplify right away. I am running into a dummy load with the KAT500 in bypass.  For the first 4-5 seconds, the amplifier is only putting out about 40-70 watts with a 20W drive.   After that, it goes up to about 350-400W.  It also seems that the KPA is requiring more drive to get it up to 500W.  So, I think something is broken, but I'm not sure what.  Any help would be appreciated. 

Thanks,
Travis
K2NP