R390A/URR Museum Radios (and other versions)

by Terry Muncey - Radio Era

We are proud to present the rarest of all R390A/URR receivers.  The following picture is for an R-1247/GRR-129 version R390A/URR that was part of the USA Apollo Space Program.  It is the only one of these that we have ever seen much less had the pleasure to have had restored to original MINT CONDITION.  Click the picture of this MINT Receiver to go to its own page where it is now for sale . . . .



This is a rare R-725/URR mint restored Collins receiver that is somewhat of a hybrid between the R390A/URR with mechanical filters and related components but uses the IF's from an R390/URR.  It was used by the military in complete direction finder sets AN/TRD-15/16/23 and 23A systems.  These direction finding facilities were mobile packaged systems with two consoles that had 4 receivers in each console.  Also these units were used by the CIA in the cold war.  There are certain attributes for digging out intelligence from the "noise floor" that was enhanced with this configuration.  We have no information as to how many were built, this one had serial number 228 on its  tag.  The contract number is also on the tag but we haven't had time to dig up any specific information about it.  Web searches  turn up "ZILCH" about this receiver. or any historical data about them.

Pictured above is a mint restored R390/URR receiver sold in May, 2006, mint completely restored receiver.

Much has been written about the R390A radio.  It happens to be what I consider to be the greatest boat-anchor radio ever built.  Surely with 26 tubes it happens to be one of the largest tube model receivers around.  It is considered by many to be the finest HF radio receiver ever built.  This is no light-weight panty-waste for sure as it weighs some 85 pounds and is built like a brick chicken-house.  It receives AM and CW signals from .5mhz to 31,999mhz.  The R390 was initially designed by Collins Radio and then re-designed under military mandate as the R390A/URR to reduce the number of tubes and to use the improved filtering enabled by using mechanical filters.  Some would like to think that this receiver is an electrical-mechanical nightmare, but to me it is a thing of sheer beauty.  Historically, this receiver was used by the military and government in most services and was classified as secret until the 1960's.  In fact some of the technical books produced by the military have still not been released of their classified nature.  This receiver also has the distinction of having served in 3 wars and oh, yes, the R390A has now served in 4 wars with the latest Iraq war seeing the R390A used in SIGINT use..  It was designed after WWII and was used in the Korean War, the Vietnam War and was used again in Desert Storm.  It is interesting to note that it was rushed back into service in the original Gulf War because many of the solid state receivers with their solid state RF front-ends were failing due to the high static charges attributed to the desert heat, low humidity and sand storms!  The R390A/URR communications receiver also happens to be one of the quietest receivers if not the quietest ever built.  It is capable of copying AM and CW signals all the way down to its -143db noise floor, all while maintaining the ability to operate in very strong and overloading signal environments and strong signal conditions.  The sensitivity of the R390A/URR is well known as it has been tested by some of the most prominent short-wave listeners in a side by side comparison with other "state-of-the-art" modern day receivers and it won hands down.  In my own office exists all sorts of optical disc jukeboxes, servers, networking electronics, switching power supplies, some 15 computers of various varieties, printers galore, scanners, monitors and all sorts of computerized switching power supplies that emit RFI hash and birdies from DC to Light!  Every radio and every ham receiver tried in these conditions always produces received birdies on the various bands that I listen to and some with +20db over S-9 signal levels!  Alas, I thought I was doomed to listening to birdies and hash until I tried my first R390A in my office.  After I hooked it up, I thought that something was wrong with the antenna system because there was no normal hash and background stuff that permeates this environment.  Then I tuned around until I was picking up some weak signals all with no interference at all.  In fact, I tried this receiver on all of the ham-bands as well as the international short-wave bands and it was devoid of any interference whatsoever.  Wow!  Valhalla, at last . . . even trying to pickup a favorite AM radio station in Dallas on 820KC, which always has interference on its signal, gave me a totally clear signal with no background hash or side spurs!!  So folks, if you are a boat-anchor person and/or really love HF listening, then you MUST obtain one of these beauties.  Now back to why I created this page . . .

My first R390A/URR is a Collins Radio built model (fairly rare as they did not build but about 6500 of them out of some 65,000 that were built).  This receiver has been totally restored and its previous owner must have like Chiquita Bananas because there was a sticker on the front panel that would not come off so the front panel had to be restored to get rid of it.  However the next one I got was a Stewart-Warner manufactured unit that worked superbly.  And my latest acquisition was an Amelco manufactured unit, which is quite rare.  The listing of contracts shows 5 being built but this must be in error as this one carried a serial number tag of 2,000.  Anyhow,  this receiver and the Collins "Chiquita Banana" radio were completely restored with several hundred hours being spent on each of these because the y were taken down to the chassis level and completely restored from the ground up.  I believe that when you see the pictures, you will agree that not only is this Collins built receiver MINT but is better than brand new as even all of the screws are polished as well as the tube shields! 

Front has been repainted and filled to perfection!

This is the Army Mil-Spec R390 case, CY979A/URR in brand new mint condition (note RFI shielding on the top (can't see), bottom and sides.  The case includes mil-spec shock mounts (4).

The mechanical gears and slug tuning is in better than new mint condition!  Even the tube shields are polished and the chassis is in mint immaculate condition.  (The gold coloring is my shadow from the light)

Even the back is in like new condition

This is the under-chassis in mint condition.  Notice the Collins built PTO and original label.  The above and below chassis on this beautiful R390A Collins built would be eaten from because it is exquisitely clean!

The following radio was completely restored and sold in 2006.  It was a black EAC R390A/URR receiver and is the only black one we have ever seen.  It truly is a beautiful radio and sold with a matching black mil-spec CY979A/URR matching case with shock mounts.  Keep in touch as we sell fully restored mint condition receivers from time to time.   If interested send or call in your inquiries as these restored beauties do not last long.

Sorry, but the above radios were sold from our radio museum.  Due to the hundreds of requests for us to sell these units, we finally did so.  But we are doing another R390A Collins restoration at the present time, so will have another one perhaps by early 2009.