I'm impressed with the clutch in the R-390/URR. It releases so much better than the ones that I had in my R-390A/URRs. I had one that was just plain old stubborn and, try as I might, I could never get it to release as good as I thought it should.
While I was working on the gear train in my R-390/URR a couple of months ago, I ended up disassembling the clutch and cleaning it up just to make sure. I really can't tell much, if any, difference before and after but it does work well. Fortunately, I think it's a rather not-too-deep dive into the front part of the gear train to get that out and service it. Good luck with it, Barry - N4BUQ > Jerry...It sounds like there is a lot of 'gunk' built up in the Zero Adj > mechanism... > > It should release quite easily and allow for smooth zeroing...I've had to > spray a few of them in 390As with penetrating fluid made for electronic gear > and soak awhile. > > Lastly, since I saw some msgs in that regard... > > I'm rebuilding the 390A I bought from Jan right now, but I ran out of 26Z5W > tubes. I went through my diode stash and found a tape string of 1N5408 > diodes and installed them with bypass caps across each of them. The thick > leads plug right into the tube sockets very very tightly with zero chance of > falling out. > > One last thing for sure!: > > Although I have spare 3TF7 tubes, I alwaysreplace them with 12BH7A tubes > with Kynar Wire jumpers across the appropriate pins. I've never been able to > measure any difference in stability between them. > > I gotta get back to this PTO work...! > > 73...Jordan VE6ZT > > ----- Original Message ----- > From: <[email protected]> > To: "'Jacques Fortin'" <[email protected]>; <[email protected]> > Sent: Saturday, November 09, 2024 1:34 PM > Subject: Re: [R-390] Zero Adjust - not quite > > > Hi Jacques, > > Apologies for not describing it correctly. When my Zero adjust is turned > fully CW, tightly, the veeder dial still moves as I turn the Kilocycle knob. > I cannot adjust for the 1.5kc incorrect readout. > > Jerry > > -----Original Message----- > From: Jacques Fortin <[email protected]> > Sent: Saturday, November 9, 2024 3:09 PM > To: [email protected]; [email protected] > Subject: RE: [R-390] Zero Adjust - not quite > > Hello Jerry, > > I do not believe that you can swap the R-390A mechanism into a R-390, as > they are different. > This is normal that the PTO still change frequency when you move the KHz > tuning with the Zero Adj. fully in: they are linked at all times. > This is the remaining of the gears that stops to move and the counter as > well. > I just checked with my own "non-A". > > 73, Jacques, VE2JFE in Montreal > > -----Message d'origine----- > De : [email protected] <[email protected]> De la > part de [email protected] Envoyé : 9 novembre 2024 14:25 À : > [email protected] Objet : [R-390] Zero Adjust - not quite > > My R-390 electronically now seems to be workings quite well. The dial > however is off 1.5kc and I cannot screw down the Zero adjust quite enough to > make the VFO adjustment. Attached is a picture. I can see the brass gear > move and the steel plate behind it move a fraction of an inch and the dial > mechanism is very tight to finger movement but not enough and the VFO > changes frequency despite the Zero adjust fully screwed CW. Also, the > spring that I assume should provide some resistance when not screwed down > seems to have lost its tension completely. > > > > I compared to the Zero adjust from a R-390A, also shown in picture. Can I > swap the R-390A into the R-390? > > > > Jerry > > > ______________________________________________________________ > 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 > > ______________________________________________________________ > 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 ______________________________________________________________ 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
