Fw: [R-390] Question about R-390 (Non A)

[Jim Temple]

----- Original Message -----
From: "Jim Temple" <jetemp@insightbb.com>
To: "Paul H. Anderson" <pha@pdq.com>
Sent: Tuesday, April 30, 2002 10:56 PM
Subject: Re: [R-390] Question about R-390 (Non A)


> All the slugs, except one, had some kind of brown shellac coating them.
One
> was black on the 16-32 slug rack.  I swapped this one with the one coil
slug
> that was unstable, and the peaking instability went away.  Perhaps
somewhere
> along the way, the slugs were exchanged, hurting the stability of the
unit.
> It would be nice to have a comprehensive tally of the various combinations
> of slugs available in the R-390.
>
> Jim
>
> ----- Original Message -----
> From: "Paul H. Anderson" <pha@pdq.com>
> To: "Jim Temple" <jetemp@insightbb.com>
> Sent: Tuesday, April 30, 2002 10:55 AM
> Subject: Re: [R-390] Question about R-390 (Non A)
>
>
> >
> > You're ahead of me on the 390 alignment, but one thing I do know is that
> > there are at least three different types of slugs for the RF deck - and
> > can for can, they change depending on the mod level.
> >
> > I'm away from my manual, but the 1962 390 manual (tm 11-5820-357-35) has
> > some info about slug changes.  David Medley had knowledge about them, I
> > think, but didn't make it clear to me if he knew which color slug went
> > where, or even if there was a scheme for that.
> >
> > We really, really (as a group) need to figure this out if we can - I
> > suspect a lot of 390/391's are suffering from mismatch of RF deck slugs.
> >
> > Paul
> >
> > On Tue, 30 Apr 2002, Jim Temple wrote:
> >
> > > Things have been a little slow, so thought I would ask a couple of
> > > questions.
> > >
> > > 1.  After aligning the RF section, the calibrator signal peaks at a
> > > different position than where the antenna coils aligned.  I did make
> sure
> > > that the antenna trimmer was at half mesh and did not touch it during
> the
> > > complete alignment.  Now, the antenna peaks at "0" and the calibrator
> will
> > > only put out about 1 volt diode load voltage.  The diode load will
peak
> at
> > > about 5 volts if I peak the antenna trimmer, which ends up at about 2
> > > O'clock.  I tried to leave the antenna trimmer in the position where
the
> cal
> > > is peaked, and realigning.  The realignment went fine, but the cal
> signal is
> > > still displaced at about 2 O'clock.  Adjusting the two trimmers on the
> > > Calibrator deck does nothing to move the peak to coincide with the
> antenna
> > > peak.  Does this anomaly suggest off value parts in the calibrator
> deck??
> > > Perhaps this is normal for the R-390?  On my R-390A both coincide
> perfectly.
> > >
> > > 2.  On bands below 16mhz, the antenna trimmer will peak with internal
> noise.
> > > At 16mhz and above, I can not detect a peak with internal noise.
> However,
> > > it will peak with an incoming signal.  My R-390A will peak with
internal
> > > noise on all bands.  Again, is this normal for an R-390?  I understand
> that
> > > the 16-32 coils, in earlier units, might have slugs and coils that do
> not
> > > realize the total potential that later units have.  Has anyone heard
of
> > > this?
> > >
> > > Thanks for your past support.
> > >
> > > Regards,
> > >
> > > Jim
> > >
> > >
> > >
> > > _______________________________________________
> > > R-390 mailing list
> > > R-390@mailman.qth.net
> > > http://mailman.qth.net/mailman/listinfo/r-390
> > >
> >
> > +---------------------------------------------------+
> > | Paul Anderson           Public Data Queries, Inc. |
> > | pha@pdq.com             734-213-4964 x308         |
> > +---------------------------------------------------+
> >
> >
>