[R-390] Fwd: {Collins} Looking for an R-390A

[Fred Moore]

Greg, 

Sorry about the delay in my reply.  I've been busy with the television channel
spectrum re-pack.  I have the following, if you are interested.  If so, I can
take a set of pictures of each.  I am able to properly pack these.  I think
the R-390A would need a box within a wooden crate.  

1.  An R-390A, Motorola, 1958, serial number 216.  All original.  It has seen
very little use.  Twenty years ago I replaced a few of the tubes and touched
up the alignment.  I then used it to listen to WEWN while writing my thesis. 
After that, it has been on display in the shack, except for a few occasions. 
It meets all factory specifications.  The gear train is clean, but I have
never oiled it, not knowing at the time just what lubricants I should use.  It
is very clean, inside and out, except for some surface dust.  The knob set is
one that I re-finished for a different unit, using a low gloss black enamel
and a slightly off-white flat latex for the line.  Apart from the knobs, there
has been no restoration -- it didn't need any. 

Before turning this up, I should first replace the capacitor feeding the
mechanical filters, check the selenium rectifier (which may need replacement
with a silicon bridge) and re-form and test the electrolytics.  Once
operating, i propose running it continuously for a few days before sending it
out. 

2. A TMC CV-591A/URR, serial number 1459, Single Sideband Converter.  (This
unit is 5.25 inches high.)  This unit has had a light restoration.  The front
panel is original.  I have saved all the original parts and will include them.
 I did the following: 
- Removed the parts needed for changing sideband selection from the Bridge.  
- Replaced all small capacitors with polypropylene.  Checked all resistor
values.  Replaced the electrolytic (as I recall).  The tubes have the Gm of
new tubes.  
- The clear alodized cabinet was dirty.  Not knowing how to clean that, I
spray painted that with a Federal std. pale gray enamel.  That was done
carefully and it looks good.  
- Being made to study economics at the time, I wandered in my thoughts and
designed a synchronous AM detector.  Its on a separate board underneath, and
is a reversible modification.  A secret extra position on the BFO Switch
activates it.  

There you have it.  What are your thoughts?

-Fred WN9i



------ Original Message ------
Received: Sat, 15 Aug 2020 05:26:18 PM GMT
From: Greg Mengell <gregorymengell at comcast.net>
To: fred_moore at usa.netCc: Collins R-390 HF Receiver List
<r-390 at mailman.qth.net>
Subject: [R-390] Fwd: {Collins} Looking for an R-390A


> ---------- Original Message ----------
> From: GORDON W2GOR via Collins <collins at listserve.com>
> To: collins at listserve.com
> Date: 08/14/2020 7:02 PM
> Subject: {Collins} Looking for an R-390A
> 
>  
> Hello All, looking for an R390-A in excellent working condition with all
filters working. Have owned several. Main concern is that the PTO does not
“warble” changing frequency randomly for SSB reception. Also looking for
Technical Materiel Corp. single side band adapter. Or Sherwood. 
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