[ARC5] When a "Good" Tube, Ain't- AN/ARC-2 Success

[Robert Eleazer]

I was aligning a BC-348-N last year and could not get the BFO on the center frequency.  I swapped out the BFO coil from one in a BC-348-J I was restoring but that did not help.  Finally the BFO quit.

That BFO uses a multi function tube, a 6SR7, as BFO, 2nd detector, and AVC.  Since the set was working OKay other than the BFO I figured it could not be the tube.  But finally I tried swapping out the tube and that did it.

I was surprised that a tube could cause an oscillator to be off frequency.  And clearly some tube functions are less sensitive to failures than are others, another surprise.

Wayne
WB5WSV