Hammarlund HQ-180A
 

I have a nice HQ-180A with a problem. The 455 kHz IF is
too narrow. There appears to be some regeneration going
on because the gain also appears to be too high. Unfortunately,
the component density is not conducive to just randomly
replacing parts. Has anyone else had this problem? Any
ideas greatfully appreciated.

73, Roger
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Hammarlund HQ-180A
 

Hello Roger:

I expect the selectivity is too narrow because of the regeneration.
Regeneration also increases the gain. It may need to be realigned
according to the manual - but I would not do that until you find the cause
of the regeneration.

It could be a tube, but more likely it is a defective bypass - either in the
plate/screen leads to the if stage or the grid bypass. Since all of these
caps are ceramic disc caps, they should still be good.

Start with the simple stuff and measure the voltage and resistance as
specified in the manual, on the if stages.

Remember to find the problem before alignment.

Colin K7FM

Hammarlund HQ-180A
 

It may well be alignment. Those 60 kcs IF's must be in alignment per the
manual or it will seem too narrow. Do that after checking the tubes in the
IF area (My experience is with the HQ-170 and HC-10).

The 60Kcs IF set the filter alignment for all of the selections (500hz, 1,
2, and 3 as I recall) double those values when switched to AM.

Hope you have the alignment part of the manual.

If that does not work check resistances and voltages.

73 Dave K4JRB