[R-390] Dead except 0 to 1 Mhz R390 non-a

[djed1--- via R-390]

Another thing to look at would be the cams and tuning slugs.  If a clamp slipped that would also cause a lack of sensitivity.
Ed

 

 

 

-----Original Message-----
From: Grayson Evans <wa4gvm at gmail.com>
To: Dan Merz <mdmerz at frontier.com>
Cc: R-390 List <r-390 at mailman.qth.net>
Sent: Tue, Mar 24, 2015 2:01 am
Subject: Re: [R-390] Dead except 0 to 1 Mhz R390 non-a


Sounds like the bandswitch is slightly off, barely making contact on one of the
wipers, or one of the wipers is corroded.  I had a similar problem.  that is the
only electrical thing that would be sensitive to slightly moving the meg. change
knob.  
This mean pulling the RF chassis, flipping it over and checking the
bandswitch position and or cleaning the contacts. 

You could maybe test by
measuring the B+ on the various tubes in the chassis (with the tubes pulled)
while slightly moving the M.C. knob.

Grayson

On Mar 24, 2015, at 6:11 AM,
Dan Merz <mdmerz at frontier.com> wrote:

> Hi,  I haven't used my R390 for about
2 years and decided I needed to check
> it out compared to other lesser radios
I've been using recently.  It's been
> sitting there in the best spot in my
radio area and other than hooking up
> the speaker it should have been ok.  It
was still set on 80 meters where I
> used it last but when I turned it on it
was more or less dead except I could
> tell the audio was working but no
indication of signals or ability to peak
> noise.  I finally went down to the
broadcast band and was able to tune in
> the three strongest local am stations
between 600 and 1000 khz.  The
> Megacycle change knob seemed to be the key to
getting it to work and it was
> very sensitive to position  and would become
alive by moving the Mhz change
> knob slightly.  And it sounded ok but I think
the signal level is somewhat
> low on the meter compared to what I remember for
the one station that I
> listen to the most at 960 khz.  And it  suddenly goes
dead  occasionally
> when I'm not touching the set but is revived by more or
less moving the
> megacycle change knob slightly.  I tried the higher bands but
could get no
> response on any band despite a lot of motion on the Mhz change
knob.  Is
> there one particular switch that is the likely culprit?  This radio
has been
> pretty reliable in the past after I worked it over quite a bit after
getting
> it 10 years ago but I don't recall having any problems with switches
back
> then.  I have the manuals but thought there might be something obvious
that
> others have encountered.  Thanks,  Dan 
> 
>
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Grayson
TA2ZGE - Ankara,
Turkey
KJ7UM
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Blog
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