[Elecraft] KPA500 RX Attenuation and TX Without Amp Key

[Mark Goldberg]

I will contact Elecraft tomorrow, but posting in case someone
recognizes the symptoms.

I just put together a new KPA500 kit. When I select Operate, the RX
through the amplifier is significantly attenuated, many 10s of dBs.
The amp will also amplify even with nothing connected to the PA Key
RCA jack. It seems to amplify OK, 35W in gives 400W out. In Standby
the RX and TX pass through the amp as expected.

It seems to me that it thinks PA Key is enabled all of the time, so
when I switch to operate it is in TX mode immediately. I do not see a
short at the RCA jack.

Any idea of what is going on?

Mark
W7MLG