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] ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
