Adam, Okay. Please keep us posted if you do decide to do that. I see where it appears to be a mix of surface mount and through hole components. I can still do surface mount but it can be a bit more of a challenge.
I do okay with SSB and the envelope detector but at one time, I had an add-on PD for an R390A that I had at the time and it was kind of nice. Of course, I could always feed the diode load out to a radio that can receive the IF and listen to it that way as well. Good luck with it, Barry - N4BUQ > Barry, > I was going to try my hand at putting them together and getting them working. > If > I can pull that off, I'd be more than happy to help the R390 community out, > probably for the cost of the board and components, which isn't too bad. > This is just a college hobby of mine, not looking to sell anything :) > On Wed, Oct 8, 2025, 13:27 Barry < [ mailto:[email protected] | > [email protected] ] > wrote: >> Adam, >> What did you plan to do with those boards? I might be interested in one if >> available. >> Thanks, >> Barry - N4BUQ >> > The only mod I had planned was using a Treetop Circuit SSB board. I had >> > ordered boards from PCB express using TTC's design and was going to try to >> > piece one together, and when I picked up this R390 it came with one that >> > was never installed. >> > The mod doesn't seem to work very well, let me take a closer look and see >> > if I can notice any mistakes, now that I have the documentation for it! I >> > appreciate it sir. >> > Adam >>> On Wed, Oct 8, 2025 at 12:06 PM Jacques Fortin < [ >>> mailto:[email protected] >> > | [email protected] ] > >> > wrote: >> >> Hi Adam, >> >> No need for an "original" BFO switch. >> >> As the W3JHR mod. used a DPDT one, and if it is still fitted there, only >> >> half of it can be used as a BFO power sw. >> >> Check how the V508 socket is wired in your IF deck: that should confirm >> >> that it was modified to use a 6BE6. >> >> You can also keep the mod. in place (if it works) unless you want to have >> >> an "original" R-390, meaning without a product demodulator fitted in. >> >> 73, Jacques, VE2JFE in Montreal >> >> -----Message d'origine----- >>>> De : [ mailto:[email protected] | >>>> [email protected] ] < >>>> [ mailto:[email protected] | [email protected] ] > >>>> De >> >> la >> >> part de Adam Morehouse >> >> Envoyé : 8 octobre 2025 11:53 >>>> À : Jacques Fortin < [ mailto:[email protected] | >>>> [email protected] ] >> >> > >>>> Cc : R-390 Mailing List < [ mailto:[email protected] | >>>> [email protected] >> >> ] > >> >> Objet : Re: [R-390] R-390 Woes >> >> Well that's interesting, I guess I'll need to find an original BFO switch. >> >> No wonder the thing didn't work, there are no substituted tubes in it. Now >> >> I get to figure out how to undo all of this. >> >> :( >>>> On Wed, Oct 8, 2025, 10:18 Jacques Fortin < [ >>>> mailto:[email protected] | >> >> [email protected] ] > wrote: >> >> > Hi Adam, >> >> > I think I recognise this mod., the clue being the 56k resistor in the >> >> > picture. >> >> > See attached doc. >> >> > If it is really the original W3JHR mod. that was implemented there, >> >> > the BFO on/off switch has been also changed for a DPDT version >> >> > (switching the audio input between the AM and product detectors and >> >> > powering the BFO oscillator at the same time). >> >> > If it is that, the BFO tube (V508) have to be a 6BE6/5750 instead of a >> >> > 6BA6/5749… >> >> > This is basically the same product detector that I use in my own R-390 >> >> > and R-390As, by using a changeover relay inside the IF deck instead of >> >> > using a substitute BFO switch. >> >> > See also the W7DI type of implementation attached. >> >> > Larry Haney also worked around this theme and used a 6BY6 tube for the >> >> > product detector because it works better than a 6BE6 in the same >> >> > configuration. >> >> > I also worked with Larry to find a way to still use the noise limiter >> >> > in the SSB mode, but the result of our experiments are not final, and >> >> > the AGC modifications we devised to “improve” the R-390 / 390A are >> >> > still not fully tested. >> >> > Stay tuned, I should have time to re-visit that during the next winter. >> >> > 73, Jacques, VE2JFE in Montreal >> >> > -----Message d'origine----- >>>> > De : [ mailto:[email protected] | >>>> > [email protected] ] < >> >> > [ mailto:[email protected] | [email protected] >> >> > ] > De >> >> > la part de Adam Morehouse Envoyé : 8 octobre 2025 03:44 À : R-390 >>>> > Mailing List < [ mailto:[email protected] | [email protected] ] >>>> > > Objet >> >> > : Re: [R-390] R-390 Woes >> >> > I might have found the issue. >> >> > Can anyone tell me if the white coax in the follow pictures is supposed >> >> to >> >> > be there? >>>> > [ https://photos.app.goo.gl/M6Qcr9mXFrZ6sgiRA | >> >> > https://photos.app.goo.gl/M6Qcr9mXFrZ6sgiRA ] >> >> > It doesn't look original to me, nor does the the resistors and caps in >> >> > front of the BFO. They seem to be hooked to V508 and RT512. >>>> > On Tue, Oct 7, 2025, 16:55 Adam Morehouse < [ >>>> > mailto:[email protected] | >> >> > [email protected] ] > wrote: >> >> > > Hey guys, >> >> > > I appreciate the pointers on my R-392, and now that it's buttoned up, >> >> > > it's time to work on my R-390. I only tested this briefly when I first >> >> > > got it, today I threw it up on the bench. Supposedly this was restored >> >> > > by Rick Mish, it is very clean (except the gear train, which has a lot >> >> > > of fresh grease...), and the front panel is pristine. >> >> > > It does pull stations, but the volume is extremely low in AGC mode, >> >> > > and gets slightly louder when placed into MGC. >> >> > > In MGC, with the BFO switched on, it plays at a normal (not super >> >> > > loud, but loud) volume. >> >> > > In AGC, with the BFO switched on, it hums, low volume audio. >> >> > > The limiter seems to have no effect, and varying the BFO doesn't do >> >> > > anything at all no matter AGC/MGC. >> >> > > I have Tom's solid state kit installed, and B+ at the AF deck test >> >> > > point is a steady 180.5vdc. >> >> > > I am going to dig out the TM's later on, I have them somewhere...but >> >> > > maybe somebody here can help point me in the right direction. >> >> > > Thanks! >> >> > > Adam K2AAM >> >> > ______________________________________________________________ >> >> > R-390 mailing list >>>> > Home: [ http://mailman.qth.net/mailman/listinfo/r-390 | >> >> > http://mailman.qth.net/mailman/listinfo/r-390 ] >> >> > Help: [ http://mailman.qth.net/mmfaq.htm | >> >> > http://mailman.qth.net/mmfaq.htm ] >>>> > Post: mailto: [ mailto:[email protected] | [email protected] ] < >>>> > [ >> >> > mailto:[email protected] | [email protected] ] > >> >> > This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ] >>>> > Please help support this email list: [ http://www.qsl.net/donate.html | >> >> > http://www.qsl.net/donate.html ] >> >> ______________________________________________________________ >> >> R-390 mailing list >>>> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 | >> >> http://mailman.qth.net/mailman/listinfo/r-390 ] >> >> Help: [ http://mailman.qth.net/mmfaq.htm | >> >> http://mailman.qth.net/mmfaq.htm ] >> >> Post: mailto: [ mailto:[email protected] | [email protected] ] >> >> This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ] >>>> Please help support this email list: [ http://www.qsl.net/donate.html | >> >> http://www.qsl.net/donate.html ] >> > ______________________________________________________________ >> > R-390 mailing list >>> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 | >> > http://mailman.qth.net/mailman/listinfo/r-390 ] >> > Help: [ http://mailman.qth.net/mmfaq.htm | >> > http://mailman.qth.net/mmfaq.htm ] >> > Post: mailto: [ mailto:[email protected] | [email protected] ] >> > This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ] >>> Please help support this email list: [ http://www.qsl.net/donate.html | >> > 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
