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NEAR-Fest Official News and Information => Mister Mike's "Mishigoss" Board => Technical Stuff => Topic started by: W1RC on July 23, 2014, 01:37:41 AM

Title: Collins R-390A Resource Page
Post by: W1RC on July 23, 2014, 01:37:41 AM
Here are several sources for information on the legendary Collins/US Army joint design R-390A/URR as well as the Collins R-390/URR radio receiver.  Please note that they are NOT the same.

This Web site is the ultimate resource for information for the R-390A.  It has everything you ever wanted to know about the R390A.   Kudos to Al, WA0HQQ, for all his work compiling this outstanding reference source.   I am proud to be listed as a contributor.


FAQ and References:

Perhaps the most comprehensive piece of collaborative work is the Y2K manual.  Here is the link to the current version:

There is an e-mail reflector on that Chuck Rippel WA4HHG and I started in 1998.  It is called the R390 List but it encompasses the R-390A as well as the R-390.  Also included are other "relatives" such as the R-388, R-388A, R-389, R-391 and R-392.  Here is the link to the archives:

You will have to select the R-390 list archives.  The List is still going strong and you can also subscribe at the same time.  I highly recommend that you opt to receive the List in the digest format.  Otherwise you may find more email in your IN box than you bargained for.

Chuck authored a R-390A "Owner's Manual" a while back.  It's another excellent resource

Finally here's a nice treatise by Don, W5OR, on basic R-390A maintenance:



MisterMike, W1RC

Title: Re: Collins R-390A Meters - Should They be Opened?
Post by: W1RC on June 20, 2018, 06:58:17 AM
Many R-390 and R-390A receivers were sold by the government with the two meters missing and the obvious question has persisted for years - What happened to the meters?

The answer is that the materials used to make the dials glow in the dark are radioactive and hazardous.   They had to be disposed of according to a specific protocol.

However before this policy was enacted many receivers were sold with the meters and another question that has persisted is how much risk there is if one *does* open a radioluminescent 390/390A meter.?

This is a very tough question.

The answer is interesting and was posted on the r-390 List by Charles Steinmetz <>

?My answer is:? I know nothing about you, or your abilities concerning careful detail work that requires fine dexterity and hand-eye coordination, or your ability and willingness to follow instructions
down to the last detail.? Therefore, I must recommend that you *DO NOT* open a radioluminescent 390/A meter *for any reason*.

If you decide to ignore this advice and *do* open such a meter, you must absolutely, positively insure that you are the only person who could possibly be exposed or endangered by your activities. I also recommend that you *study* (not just "review") the AEC/NRC cleanup protocols, as well as the standards and protocols that govern working with materials that contain Ra226.? You will also need to ensure that you have laboratory-grade radiation monitors ($$$) available at all times.

At a minimum, you will need an indoor space that is relatively well sealed (doesn't exchange air with the outside environment).? You will need to enter this space and seal it up, and have available at least one laboratory-grade radiation monitor (preferably two, for sanity checks)? You will also need to have a reliable communications device you can use to contact your local HAZMAT authority, as well as the contact information for that authority.

This means that no part of any dwelling occupied by others may be used (whether they are there at the time or not).? *Period*.? You at least need a standalone building (preferably small) located at least 50m from the nearest other building.

So, the drill is:? Seal yourself in and do your work, continuously checking the radiation monitors.? Clean up, putting all leftover radioactive materials into radiation-safe containers that are shielded
for the types of radiation emitted by the item(s) you were working on (alpha, beta, and gamma in the case of Ra226).? Check for residualradiation *everywhere* in the space you are working in, including your own person and clothing.? Check again.? Check a third time.

If everything tests clean, arrange to have your local HAZMAT authority pick up the waste container(s) (or transport it to them, if permitted in your jurisdiction -- but be sure to *CALL FIRST* to alert them that you will be coming).

Now, here is the hard part.? If there is any residual radiation, *STOP* before you spread it any further.? Call your HAZMAT authority, explain the situation to them, sit down calmly, do not move or stir the air, and wait patiently for the nice people in radiation suits to come and decontaminate you and your space.

Now, do you still want to open up your meter?? If so, (1) keep your eyes wide open, (2) take full responsibility for what you are doing, understanding that radioactive dust is easy to spread and virtually impossible to collect after it is spread, and (3) take all of the precautions described above.? I have done this in the past, but I would not do so today because my manual dexterity may no longer be up to the challenge due to aging.?
Title: Re: Collins R-390A Resource Page
Post by: W1RC on September 05, 2018, 03:44:07 AM
Hi Gang!

Every once in a while something really cool comes along that is of great interest to R-390A radio folks like us - and here it is!

This 78 page .pdf file is a collection of handouts is from the US Navy Technical Training Center in Pensacola FL.  It is the ?A? School R-390A training handout for the Cryptological Technician Class ?A? Cryptologic Maintenance Course (A-102-109).  The document is not classified and in the public domain so distribution is completely legal.

This handout is an absolute gold mine of information on how the R-390A works and how to maintain it.  Included (page 43-49) is a very interesting document on how to modify a R-390A for SSB reception without using an external adapter.

It is a very interesting and informative read.  Some of the pages especially towards the end are very light and hard to read but it is all there.  Perhaps some day someone with too much time on their hands will retype it.



Michael, W1RC

Download the handout:

Thanks to Chaz Jedlicka for sharing this wonderful resource with us.