[Johnson] Old Resistors

[David C. Hallam]

I ran into an interesting situation yesterday.  I was finding multiple 
spurious signals when I tried to zero beat a received signal with my 
Invader 2000.  I put it on the bench to find out why.  It turned out to 
be a carrier oscillator problem.  The unused oscillator was not being 
turned off so the carrier frequency was a mix of both the 9001.5 and 
8998.5 KHz frequencies.  The cause was both of the grid dropping 
resistors on the 12AU7 oscillator were WAY out of spec and insufficient 
bias was applied to cut off the unwanted oscillator.

The resistors are supposed to be 820K.  One measured 3.2M and the other 
4.1M.  Has any seen old resistors go this high in value?  This makes me 
wonder how many other resistors in this thing have a similar problem.

David
KW4DH

-- 
There are four boxes to use in defense of Liberty:
SOAP, BALLOT, JURY AND AMMO. Please use in that order.
VOTE for REAL CHANGE in 2012.