[R-390] growly BFO

[rbethman]

Then tou back up to the BFO, and begin the hunt for its source of the 
"hum".  Is it adjusted properly?  There is an adjustment on the left 
side of the IF module to attempt to clean up the waveform.

How about the BFO oscillator?  Got a leaky cap in that arena?

The OLD method(s) - Divide, (the circuit into sections), and conquer.  
Isolate and contain.  (Use a signal generator in lieu of the BFO and see 
if this changes the situation.  Could even be a need to change a tube.  
Though it may not be obvious.

It can and will take time, although it is "kind" of trivial, it is an 
extremely annoying problem.

Bob - N0DGN

Larry Snyder wrote:
> I found the ground strap cleanup procedure, but I think that would
> be fixing the wrong problem.  This is hummy without even looking at the
> PTO, but only when the BFO is on.
> -ls-
>
> odyslim at comcast.net wrote:
>   
>>  Larry,
>>
>>  If you learn anything, could you pass it on? 
>>
>>  I have learned by cleaning the ground strap and spraying it with a bit of
>> de-ox it will clean up a lot of the warble but I have 2 or 3  that I have the
>> same problem as you. I am using the same mod as well
>>