Sounds like your meter is acting as an antenna & the
RF amp is working OK. That leaves the AGC, balun &
rf switching. The balun is where the antenna hooks on.
All it does is change the balanced 300 ohm to unbalanced
75 ohm. Check ohms with a meter. Dont know the specs
of the 3BC5 but -1.5V may be enuf to turn the tube off.
Remove the AGC line & see what happens. You can
also use a wire to inject the signal along the path til
the RF amp tube.
good luck
Zeno
