[Drake] AC Hum in TR-4C speaker`

[Tony Sokol]

Happy New Year!

     Before I spend a bunch of time chasing my tail trying to solve an 
AC hum issue in my newly acquired TR-4C, I thought I would try the 
reflector.  I found a pretty nice AC-4 to go with the TR-4C on Ebay.  I 
also found an AC-3.  I just installed the AC-4R kit in the '4 which is 
really nice!  The problem is that there is a noticeable AC hum in the 
speaker all the time.  I hear it when I key the mic. or turn the RCVR 
gain down.  It's always there and fairly loud.  BOTH supplies exhibit 
the same problem even after installing the new AC-4R upgrade.  Now I am 
thinking maybe a tube with a filament to cathode short.   Anybody run 
into this before?

Thanks and have a great 2011!

73
Tony - W9JXN