[Hammarlund] HQ-170 refurbish

[Rodger]

Hi Neil,

If you have an early model HQ-170 like mine then you may run into a 
problem with the fixed mica caps that are built in as part of the IF 
transformers.  My 170 is one of the early ones where the caps are 
basically open to the environment and over time dust/carbon tracks 
develop to ground and take out the associated resistors.  After having 3 
of them fail I removed all of the remaining ones and replaced them with 
standard sealed mica units. Hopefully yours is later production and if 
it was an early one and kept in a very clean environment it still may be 
OK.  I just wanted to pass this along so you can check this during the 
rest of the restoration process. 

Most of the caps used in the HQ-170 should be disc ceramics and there is 
no need to replace these as they don't commonly fail.  You need to be 
careful aligning the final IF as this is very critical to receiver 
performance.  Most RF generators do no go this low but if you have an 
audio generator it should go this high, again just make sure that you 
check it against a counter or other reference before alignment.  The 
HQ-170 does a great job under conditions of heavy interference on any 
mode but mine spends its time paired with a Viking 2 for AM and CW.

Good luck with your new receiver.

73, Rodger WQ9E

Neil wrote:
>  Hello all,
>
> I've got an HQ-170 that needs some tender care. Overall,
> it's been
> well treated, but switches and rotaries are all tight. 80
> meters is
> nearly dead... roughly 30db below the other bands. I'm about
> to
> do the basics: tube check, cap replacement, alignment, etc.
>
> Does anyone know of specific resources that would help me
> out?
> I can find a manual online, but wonder if other's who have
> tackled
> an HQ170 or HQ180 might have some good references.
>
> I'm a new subscriber to this list, so if there are archives
> or resources
> that are frequently discussed, and that I'm unaware of, I
> don't mean
> to be adding noise.
>
> Thanks much for any leads,
> Neil Murphy
> KI6HJS
>
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