Greetings, John... I noted you said you didn't have a manual or schematic for this receiver. Before you do anything else, do yourself a giant favor and go to these two websites:
R-390A FAQ Page <http://www.r-390a.net/faq-refs.htm> An exhaustive list of carefully gleaned technical references on this fine receiver, in downloadable PDF format. R-390A Y2K Manual (Release 3) <http://www.r-390a.net/Y2K-R3/index.htm> A complete annotated and updated version of the R-390A Technical Manual. This manual has been painstakingly compiled, rewritten for clarity and accuracy, and is kept updated by a large group of experienced techs who own and have worked on the R-390A for many years. Downloadable (PDF files) by chapter, or as one massive file. Just about anything you need to know is available on these two web pages. I have only rebuilt five of these great receivers over the years, and I have a complete set of the original military versions of the R-390A manuals, but like most of us R-390A nuts the "Y2K" manual is my working bible for this receiver. It is much easier and faster to use than the original military versions. You will benefit (at no charge, no less!) from the hundreds of hours invested in updates, corrections, and clear, easy to follow troubleshooting information contained in the latest release of the Y2K Manual. These guys have invented the wheel for you, don't waste time reinventing it. :) Have fun, Jerry W5KP John King wrote: > Thanks for the reply, Grant. My R 390 doesn't mute when terminal 9 is > grounded. I have connected an alligator clip lead to terminal 9 and then > connected the other end of the clip lead to terminal 16 which is ground and > there is no effect. I can't figure out why there is no effect when terminal 9 > is grounded. What do you think, Grant? I do not have a manual or schematic > for the R390. 73, John, K5PGW > > > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html

