[R-390] zero adjust knob

[Larry H]

Hi Jose,  You're scenario is very perplexing.  It's not unusual for the
'zero adj' to change frequency as you turn it in the cal position, but not
as you describe your problem.  I'm not sure what's going on there, but I
can't think of why it's different in cal and agc.  Are you using cal in the
same band as when you are using the known station?  How strong of a station
is it?

Regards, Larry

Regards, Larry

On Fri, May 3, 2019 at 8:10 AM jm <josemic at gmail.com> wrote:

> Hi fellows
>
> I have an annoying problem with the zero adjust knob. When I use the
> calibrator of the receiver things are well.
>
> The problem arises when I try to zero-beat using a broadcast station with a
> known frequency.
>
> Loose the knob, zero-beat and when I am tightening the knob I can realise
> how the signal measured with the carrier meter begins to decline. The more
> I tight the more the needle descends. The final result is a mismatch of 1-2
> kcs.
>
> It is strange for me that the problem occurs only in the AGC o MGC position
> and not with the calibrator.
> Can you help?
>
> Thanks and regards
>
> Jose Isasa
> EA8DCP
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