[R-390] R-390A BFO --service .

[Pete Williams]

​ If you are servicing a   IF  module  with non functioning BFO, and
suspect someone  has been there before you, Take  note........
Checking plate  and  screen  might show  incorrect  voltages  leading to
checking caps  and   R's.
It's not  necessarily so  and the problem. remains ...... Previous
attempts  by the ungodly if  they have taken out /replaced the  oscillator
assy.
may have transposed the  two wires  going to  terminals #2  and #3. Check
with  schematic and  conform their  connection to the  tube  socket.. Faith
and performance restored after a  reversal.
...... and whilst on the  unusual. , ensure  a replacement or even a
current installed power  xfmr has no obvious  corrosion around the  ceramic
studs. I didn't with result AC input to terminal
#2 blew its  stack,, exploded out of the  case  and took the line filter
with it..  ..nasty !
 Cheers
Pete  VK3IZ