Also, the crystal deck is removed separately from the RF deck in the R390. It needs to be synced somewhat like the one in the R390A but has its own Oldham coupler to deal with.
All in all, just a different level of "fun". Good luck with it, Barry - N4BUQ On Sat, Nov 29, 2025 at 4:31 PM Jacques Fortin <[email protected]> wrote: > Hi Robert, > The problem is that it is not the same procedure than for a R-390A. > You have to install the "green gear" first and use the proper MHz and KHz > default settings (3.000 if I remember well...) > Not the "7+000" of the R-390A. > Depending also on what you have as a reference manual. > I prefer the 1st Collins from 1953 or the TM11-856, but only with all the > corrections C-1, C-2 and C-4 applied (as in the 1958 edition) ! > If the green gear is lost, well, you will have to re-sync all the gear > box... > Not impossible to do, but it takes time. > Once you will be in the RF deck, change the C231 (bathtub 50µF/50V RF gain > line decoupling cap) which will give you problems sooner or later. > Read the removal and re-installations carefully ! > > 73, Jacques, VE2JFE in Montreal > > I've read over the years about doing this but never had the need until > now, so would appreciate pointers to any info about removing the RF deck > from the R-390 (not "A"). > > The mechanicals are in good shape, but I've isolated a static-like noise > to the 3rd mixer so it's got to come out. > > If it is the same procedure as for the R-390A, then I can refer to > information in the "Pearls" and elsewhere in addition to the manual. > > Thanks and 73, > Bob W9RAN > > ______________________________________________________________ > 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
