Norm
Very nice photography! It does look like the R-390/URR receiver was gently
used but it did clean up well. What I have collected has seen some prolonged
use with some half moons around the frequency knobs. Did you get your R-389
from W5OR?
Regards,
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence. Murphy
On Saturday, February 14, 2026 at 02:31:27 PM CST, Norman Drechsel
<[email protected]> wrote:
Hello to all on the group. I've been a long time member and don't recall
having ever posted, but couldn't help but chime in on R390 gear cleaning. I
have restored about two dozen R389, R390, R390A and R392 receivers over the
years (and still have one dozen). Gear cleaning was always a challenge and
(unless something was broken) couldn't bring myself to taking all those split
gears and shafts apart and then putting it back together. It's a formidable
task and I salute all who have been brave enough to meet the challenge.
Here are links to photos of an R390 RF deck I restored about ten years ago:
http://www.wa3key.com/r390/r390-11.jpg
http://www.wa3key.com/r390/r390-12.jpg
http://www.wa3key.com/r390/r390-13.jpg
http://www.wa3key.com/r390/r390-13.jpg
http://www.wa3key.com/r390/r390-15.jpg
http://www.wa3key.com/r390/r390-16.jpg
Here's how I do it. The obvious first task is to drop the front panel and pull
the RF deck. After tying the connectors back and removing the Veeder Root
counter, I attach four Nylon plates to the front panel like feet so it can be
stood face down in a large ultrasonic cleaner. I fill the tank with a mixture
of water and Simple Green so the level covers all the gears but keeps the
chassis and electrical components dry. I then use an emersion heater to warm
the cleaning solution and run the ultrasonic for about 15 minutes. If all the
gunk didn't come off I run for another 10-15 minutes.
Then the tank is drained refilled to the same level with WD-40 (yes that's a
lot of WD-40, but it stays clean and is reusable) and run the ultrasonic for
another 10-15 minutes. This step displaces every trace of water, even from
between the split gears and shaft sleeves.
Following the WD-40 cycle I reclaim the WD-40 (the water stays at the bottom so
is easy to separate) and then spray the gear assembly (outdoors) thoroughly
with compressed air which only leaves a film behind. A thin application of
synthetic motor oil with a brush is the only lubrication I use.
This process works great for the R390, R390A and R-392, but the R389 is a whole
different "animal" and can only be done the hard way.
If you'd like to see the rest of the R390 photos, replace the digits following
the "-" in the URL with "01" thru "42." Or if you want to view the photos from
all 3 restorations, go to
http://www.wa3key.com/r390/
http://www.wa3key.com/r390a/
http://www.wa3key.com/r389/
and you'll find a list where you can click on one photo URL at a time and use
your browser's back button to return to the list. I decided to take document
these restorations because all three were original and unmodified.
73 de Norm - WA3KEY
[email protected]
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