[Hammarlund] HQ-110 stability

[Kenneth G. Gordon]

On 8 Feb 2010 at 12:15, Singley, Rodger wrote:

> Ken,
> 
> The HQ-110 is a decent dual conversion receiver and its only real
> deficit is the selectivity is somewhat lacking.

But it does have an effective "Q" multiplier and a REAL BFO. :-)

Selectivity is plenty good enough for me. I started out with an S-41G, so I 
have permanent "built-in" selectivity.

>  But the RF
> performance should be as good as the closely related HQ-170 and the
> stability is not that bad on my HQ-110.  Unlike the low cost HQ-100,
> it has the potential to be a good receiver.

Well, I had always thought so until I used it this past CX. I was 
disappointed in its selectivity. When I partially restored it some years ago, 
the sensitivity was right up there with the better receivers. Furthermore, I 
don't recall seeing this instability then, but then again, I didn't really use it 
much until two weekends ago.

> 
> I would suggest monitoring the HFO and BFO on external receivers and
> see which one is responsible for the shift and this will help you
> narrow it down.

Good idea. I'll do that.

>  I am assuming the problem is occurring on all bands
> and not just 40 and up,

Yes. Both 80 and 160 meters are also so effected.

> if just on 40 and up then the 2'nd conversion
> oscillator becomes a prime suspect.  Once you narrow it down to a
> stage it should be easier to solve.

Yes. That is one reason I asked the "collective wisdom." 

Thanks,

Ken W7EKB