[Hammarlund] HQ-180A 60 KHz IF Problem - Suggestions?

[wmacleod2 at sympatico.ca]

Hmmm very unusual that all tuned sections respond the same way. 
The only thing they have in common are the ganged switches...unless someone
changed their capacitors.

Are you sure you are tuning the correct slugs? 

I get mixed up some times and when nothing moves I stop and realize the
mistake,.


Wade






-----Original Message-----
From: hammarlund-bounces at mailman.qth.net
<hammarlund-bounces at mailman.qth.net> On Behalf Of Steven Reed
Sent: Wednesday, February 2, 2022 10:28 AM
To: Hammarlund at mailman.qth.net
Subject: [Hammarlund] HQ-180A 60 KHz IF Problem - Suggestions?

I've been busy restoring a beautiful old HQ-180A.  Previous owners have
struggled with the IF of this radio and I localized and fixed the major
smoking gun:  V7's cathode resistor had drifted from 68 ohms to over 400
ohms.  I'm now left with the aftermath of all the fiddling and prodding
that's happened to the IF section over the years.  The problem I'm now
facing is that the 60 KHz IF section isn't resonant at 60 KHz and won't
align correctly - I can't find a peak at 60 KHz in any of the IF
transformers (T6 through T11).  The radio is correctly set according to the
manual for this procedure.  However, if I vary the signal generator some,
the transformers will find strong peaks around 54 - 56 KHz.  Been through a
lot of steps trying to isolate this but keep coming up empty.  The entire 60
KHz IF chain appears to be affected - injecting signals further down the
line produces nothing different.  What would drive the resonant frequency of
the ENTIRE 60 KHz IF chain down like this?

73 - Steve, KW4H

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