[Collins] KWM-2A Meter Problem

[EOLEEJR at aol.com]

Hello, My KWM-2A meter is not working in the receive mode. The needle is  all 
the way to the right and the RF gain has no effect on it. The radio receives  
ok, although when the RF gain is fully clockwise it does not seem to have the 
 volume that it normally has. The meter works fine in the transmit mode. When 
the  radio is turned off the meter goes back to 0. Any suggestions on what to 
check?  I am thinking it might be a tube problem.
 
Thanks,
Gene
WB4NUM