John, Good to hear from you, and glad the radio made it home.
Short answer: you've got something very special. That contract number, W36-039-SC-44552, is the original Collins development contract for the R-390. Under it, Collins built only three R-390 prototypes for the Signal Corps at Fort Monmouth before any production radios were made: R-390 No. 1 — January 1951 R-390 No. 2 — September 1951 R-390 No. 3 — February 1952 The "X" in (XC-2) means experimental. Your plate says Serial No. 2, so you almost certainly have R-390 No. 2 — the second R-390 ever built, delivered to Fort Monmouth in September 1951. That's a museum-grade radio. It pre-dates the entire production run. Before you do anything else with it, take a lot of photos — inside, outside, the data plate, any paper tags, any handwriting on the chassis. Don't clean anything off. The little details on a prototype are part of its history. The primary source on these three radios is the Collins Final Engineering Report (CER No. 297), here: https://www.collinsradio.org/wp-content/uploads/2012/04/R390-CER-No-297-Signal-Corp-Final-Eng-Rpt-Includes-R-389.pdf And contract background is on r-390a.net: https://www.r-390a.net/faq-manuf.htm If you post some interior photos to the list, several of us can help you figure out exactly what's original and what isn't. Quite a find, John. Glad it followed you home. 73, Mike Peace VK6ADA r-390a.net Administrator On Wed, May 20, 2026 at 3:39 PM John Flood via R-390 <[email protected]> wrote: > Greetings, > After the stroke i had 3 years ago and selling off all of my > R-390,R-390A,R725,and R-392's that I had because the weight exceeded what I > was allowed to carry.,. one of the radios i sold followed me home from a > flea. Forgive me if I asked this before, the brain is quite dusty, This > unit has a phenolic tag from Collins R-390(XC-2)/URR Serial No. 2 Order N. > W36-039-SC44552. Does any one here know what the XC-2 mod was? The owner > had a great laff when I asked him about it... He said you should know you > sold it to me! I do recall that now and told him I must have told you! > At least i had the stroke as an excuse! Well needless to say with the help > of my son. the beastie is now inside my shack Now starts a mission to > again figure out what's so special about this one. > John Flood N1JAF > T email list: QSL.net - Donate Site > > | > | > | > | | | > > | > > | > | > | | > QSL.net - Donate Site > > > | > > | > > | > > > > > ______________________________________________________________ > 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
