[Collins] 32S1 crystals

[Gerald]

On Wed, 2005-09-21 at 16:04 -0700, Glen Zook wrote:
> I believe that the Service Bulletin is to change the
> balanced modulator from the 2 diode circuit to the 4
> diode format.  I did this in my original 32S-1 (didn't
> have the SB but did it from my 32S-3 schematic) and it
> definitely helped considerably.  Then after very
> carefully aligning the transmitter a station less than
> 1/2 mile from me could only hear 1 signal even when I
> turned on my linear.

Yes the SB adds two diodes. It doesn't rearrange the circuit as much as
later factory revisions.
> 
> Unfortunately, there are not that many amateurs out
> there today who either have the test equipment and/or
> the skills required to do the modification and/or
> alignment necessary to assure the proper operation of
> the 32S-1 / 32S-2.

There are many who would "restore" an S-line. Making such a circuit
change is easier than replacing all the black beauties without knowing
how to solder. As for test equipment, all it takes is a receiver to hear
the carrier and an insulated screwdriver to tweak the variable capacitor
and balance pot for minimum carrier while in SSB mode.

> 
> That is why I don't recommend using the 32S-1 / 32S-2
> on CW.  If the operator is a competent technician then
> there is nothing to worry about.  Unfortunately, that
> is not always the case.
> 
> Glen, K9STH


-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer
50 years a ham as of today.