[R-390] Fw: Alignment help. (update).

[Jim Temple]

Hello to the list,

The tube test adapters have been found.  Thanks for the suggestions and
offer to get some to me.  I will be back after getting some voltages.  So
long for now.

Jim

----- Original Message -----
From: "Jim Temple" <jetemp@insightbb.com>
To: <r-390@mailman.qth.net>
Sent: Tuesday, March 26, 2002 7:12 PM
Subject: [R-390] Fw: Alignment help. (update).


> Hello to the group,
>
> I have finally found some more time to work on my R-390A.  I have received
> several good suggestions, but find that I am stalled because I have no
tube
> socket test adapters (for testing voltages and resistances).  I have
> discovered that testing most voltages is impossible without some of these
> adapters.
>
> Before I can proceed much farther, I need at least one of the 9pin and
7pin
> tube test adapters.
>
> Perhaps someone on the list will assist me in obtaining the adapters
needed
> to proceed, efficiently, with test measurements.  Someone must have a few
> spares that they will sell.  Thanks.
>
> Regards,
>
> Jim
> 73, KF4ICZ
> ----- Original Message -----
> From: "Jim Temple" <jetemp@insightbb.com>
> To: <r-390@mailman.qth.net>
> Sent: Thursday, March 07, 2002 3:09 PM
> Subject: Alignment help.
>
>
> > Hello to the group,
> >
> > I have owned a "massacre" R-390A since the end of Dec '01.  Since that
> time
> > I have spent many, many hours in cleaning, recapping, and generally
> solving
> > one problem that reveals another problem.  The solved problems generally
> > relate to cleaning out the intrusive dirt and grime from the storage.
> Many
> > problems have been solved by reworking grounds and intermittent
contacts,
> as
> > well as a few noisy caps and resistors.
> >
> > I am at the point where only the alignment remains, I think.
> >
> > What I am experiencing is this:
> >
> > 1.  The equimpent I have is a good freq counter, VTVM, and Heathkit
signal
> > generator.  All work fine, except that as the alignment progresses, the
> > radio becomes so sensitive at the higher bands, that the signal
generator
> > will not attenuate enough to keep the diode load at approx 7-8 volts.
At
> > this point I have been reducing the radio RF gain to reduce the voltage
> > present at the diode load point.  This works fine, except that the
higher
> > bands are ALIGNED WITH THE RADIO RF GAIN REDUCED to about 1:00 position.
> >
> > Now, after alignment, with the RF GAIN CONTROL UP FULL, the lower bands
> work
> > fine and the antenna peak control is fine.  However, the higher bands
seem
> > to overload and oscillate with a screeching or motorboat putting sound.
> > When detuning the antenna peak control the overload seems to reduce
> > somewhat, but with rotation of the antenna peak control, there is much
> > popping and static.
> >
> > 2.  I am getting the impression that the alignment must be performed
with
> > the RF gain control up full, and the signal generator attenuated enough
to
> > present a diode load voltage of about 7 volts or so.  If peaked with the
> > radio RF gain reduced, my impression is that, after peaking, a normal RF
> > gain position will introduce overload at the bands that were aligned
with
> > the RF gain reduced.
> >
> > SO NOW MY QUESTION..........
> >
> > Does the overload, screeching, and motorboat putt sounds seem to be a
true
> > alignment problem (obtaining an attenuator), or is there a remaining
> > component problem that is preventing a good alignment???
> >
> > Thanks for your past advice, and am looking forward to completing the
> > restoration of this great radio.
> >
> > Sincerely,
> >
> > Jim
> > 73, KF4ICZ
> >
> >
>
>
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