[Elecraft] Connecting a K2 to a KPA500

[Ariel Jacala]

Hi to the Elecraft Reflector

I just acquired a KPA500 and connected it to a K2.  I  have the output of the K2 connected to the input of the KPA500.  Things checked out through a dummy load in terms of loading the amplifier.  The KPA500 is then connected to a resonant antenna.  When on standby, I can hear signals through the antenna.  When I press operate - I can no longer hear the signals.

When I press the tune button on standby, the KPA500 does not measure  SWR.  Is this normal?  The KPA500 was previously operated with a K3 with the K3 cable to the KPA500.  I can key the KPA500 with the K2 and it produces expected power with the recommended drive levels.  I am worried about not hearing signals when in operate mode.

Do I need to update the firmware?  Why can't I hear signals from the antenna with the KPA500 in "operate"?  

Any help is appreciated.  

Thanks 

Ariel NY4G

Sent from my iPad