[Hammarlund] Re: HQ-170A S meter problems

[Joe W2KJ]

Howdy Hammarlunders:

Didn't get a response  last week so am re-sending in the hope
that someone can help out this week.

                                    73, Joe W2KJ


> Have been chasing my tail trying to solve a problem with my
> HQ-170A S meter.  Perhaps the great minds on this list can
> help me out.
>
> After warm-up the meter pointer is pinned to the left side
of
> the meter.  Only huge signals will move it upwards to the
> right.  I cannot get the S meter to zero out at all nor can
I
> get it to "unpin" using the S meter ZERO ADJUST pot.
>
> I have checked all the usual suspects, tube, resistors
around
> V13, etc.  Have replaced V13, the 12AU7A with several others
> (checked OK on B&K 747B tester) and still have  the same
> symptoms.
>
> Interestingly, when I swap the 12AU7A for a 12AT7A, the
meter
> unpins and the pointer settles to about mid-range.  It will
> swing upwards to the right on normal strength signals!!  The
S
> meter ADJUST pot will move the pointer left and right but
> still will not zero the  meter pointer.
>
> I have checked all the past digests with no luck as to what
> might be causing the above problem(s).  Sure hope someone
has
> been able to solve this anomoly and can help me out.
>
>                                 vy 73, Joe W2KJ
>
>
>
>
>