[ARC5] OT? bc-348 bfo question

[Robert Eleazer]

I had an identical experience with my BC-348-N, and found that SSB could be copied on MVC but not on AVC.  I also found that the problem was worse on 80 meters than on the other bands; I attribute this to the receiver likley being more sensitive on that frequency.  I can even copy SSB on 17 meters better than on 80M. 

But while performing the alignment I also found that the BFO was acting strange, straying off freuency.  I took the BFO coil apart to see if it might be the problem and ended up replacing it with the BFO coil from a badly hacked BC-348-J I was restoring, to no effect.  The problem got worse rapidly and it turned out that the cause was the tube.  That is a two section tube, both a diode and an oscillator, and while the diode was still fine the oscillator section had gone bad, displaying a center frequency excursion before quitting entirely.  

So you might try plugging in a fresh tube.

Wayne