[Hammarlund] HQ-180(A) 3035 kHz Xtal Osc Alignment

[Kim Herron]

Hi Dallas,
>Has anyone aligned the 180(A) 3035 kHz xtal osc?  I recently bought  a 
>damaged and unaligned '180 (the usual "in good operating condition" 
>according to the seller) in which one of the xtal osc cores had been 
>screwed all the way in.  Presumably the other xtal osc alignment core was 
>tampered with as well.  I believe I can fix it, but would like to 
>correspond with anyone who has "been there and done that."  Thank you, Dallas.

          That 3035 crystal setup in the front end of the receiver is not 
an oscillator, it's a crystal filter.
None of the transformers peak that part of the circuit either.  Now, you do 
have the secondary of the
3035 side of the transformer going through the crystal filter, but the 
transformer actually peaks on the frequency
determined by the 2580 oscillator in the second mixer tube circuit (working 
from memory here, so the stage may be different).
I'm fighting with one of those beasts right now.  Mine had T-1 out of it 
and it wouldn't peak on 455 so I had all kinds of stuff
going on.
      I can tell you this about this radio.  A VERY GOOD sig gen is a 
necessity to work on it and a dead nut freq counter as well.
You'll create more trouble than you fix without them.  I'm assuming that we 
already have a good scope.
     That 3035 crystal filter does have a freq adjust cap on it to tweak 
the center of the bandpass so that the third IF works properly.
You can tell if your trouble is in the 1st IF or band pass by taking stock 
of how the receiver performs on the 4 lower bands.
The 2580 osc and the 3035 band pass filter do not operate on the first four 
bands.  If your trouble is on all the bands, then it's time to look
at the second or third IF as the source of your trouble.


Thanks!!

Kim Herron  W8ZV
1-616-677-3706
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