Reminder FWIW - the R-390A manufacturing drawings are all on line at https://www.navy-radio.com/rcvrs/r390a/drawings.htm
You can look in the manual at the parts list to see the drawing number that covers a particular part. https://www.navy-radio.com/manuals/r390a-063-2010-7004.pdf Have fun, Nick England K4NYW Chapel Hill NC www.navy-radio.com On Tue, Jun 16, 2026 at 11:45 AM rochep--- via R-390 <[email protected]> wrote: > > Actually I think I just need to get to the gearbox disassembly to the point > of Steps/Pictures 12-16 in Chapter 10 in the manual. Once I get the gear off > the MHZ shaft I am good. > > From: [email protected] <[email protected]> on behalf > of rochep--- via R-390 <[email protected]> > Date: Tuesday, June 16, 2026 at 11:40 AM > To: Jacques Fortin <[email protected]>; 'Jordan Arndt' > <[email protected]>; [email protected] <[email protected]> > Subject: Re: [R-390] Removing Megacycle Change shaft > > I agree, taking out the gearbox is what I am looking at. Got alot more to > learn before getting at this, I assume the entire RF deck and gearbox comes > out together. Lots of YouTube videos to follow. Thank you all! > > Paul > > From: Jacques Fortin <[email protected]> > Date: Tuesday, June 16, 2026 at 11:21 AM > To: 'Jordan Arndt' <[email protected]>; 'PAUL ROCHE' <[email protected]>; > [email protected] <[email protected]> > Subject: RE: [R-390] Removing Megacycle Change shaft > > Hi Jordan, > Not sure about this clamp ID, but it must have a 13/32" hole to fit the gear > part that it have to hold to the shaft. > See attached picture. > The ultimate problem that Paul is facing will be to remove the broken clamp > there without damaging anything else around. > Using a two-part clamp is a good idea, medium hard to machine, but there can > be other hidden mechanical damages in his set. > We never know what happened to these radios before. > To maintain (or restore) those requires both electrical and mechanical > skills. > > IMHO, Paul should attempt a gearbox disassembly, cleaning and reassembly > (Y2K-R3a manual Chapter 10). > At least, he will be able to catch any other marginal mechanical flaw within > during the process. > This is one of the worst case I seen so far: a clamp broken at the worst > possible place, but.. any other broken clamp within the gearbox will require > disassembly, anyways. > > There is other "stupid" damages I was able to see in my "spare" EAC RF deck > yesterday night: some of the clamp screws heads are "eaten" internally, most > probably because someone tried to use Allen bits instead of Bristol ones on > those. > That one will be due for a complete overhaul, I believe: it is completely > gummed up, also. > > PAUL: just a comment... > The answers you provided came to me OK directly to my email address, but the > same text did not "passed" thru the forum: the postings came to me "empty". > I cannot tell why, but have a check... > > 73, Jacques, VE2JFE in Montreal > ______________________________________________________________ > 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
