[R-390] NSA True or False

[wa4aos at aol.com]

 Hi Group,

It was with great interest that I read all of the comments regarding the R 390A and if it was ever listed as classified. For years I worked as a Systems Engineer with DEC, Digital Equipment Corp. One of my cohorts, Howard, in my department had spent a number of years in the Navy after graduating from Clemson University; He had one of those Top Secret Clearances. He was the one on our team who was allowed to go into restricted areas of the Savannah River Plant and had to have an FBI clearance checkout before he was allowed to have those privileges; seems like he had a Q clearance but I may be wrong about that.

I mention all of this because, one day I bought an R 390A from a local Ham in the Augusta, GA area and I had it in the back of my company car for a few days. My cohort, Howard, came in one morning and saw this receiver that he knew well resting in my Taurus Wagon rear compartment. Howard rushed into my office area and asked impatiently, "where did you get that R 390A receiver." I was shocked that he knew what it was, since he was not a Ham or had never talked to me about HF communications. I told him I had bought it from a local ham for $85; this was 1986, OK, they were often very cheap and plentiful back then..

Howard told me that he didn't understand how I got the 390A but it was classified equipment. I started to laugh uncontrollably and explained I had seen these for years at Ham Fest since the 70's and I was quiet certain they were NOT CLASSIFIED. He stormed off and didn't talk to me for a day or two.

Later, I sat down with Howard and told him I wanted to know more about his concern of these receivers being classified. Howard, took many secret's to his grave after his untimely death in his early 50's later on. He told me that without going into any specificity, that he was Navy trained on a Top Secret Crypto project that had to deal with National Security. He went on to explain this had to do with decoding enemy signals, Russian, as I recall and that they used the R 390A's on that project. 
I guess Howard believed the 390A's were classified because the project was classified. He was very sure the 390A's were still classified even after I showed him advertisements in QST where they were being sold. Anyway, Howard ended up buying the receiver from me for $100. I made enough profit to fill up my Taurus back then. Hi

Now for my question. I have heard for years that the NSA still uses R 390A's for weak signal work because of it's very quiet front end and sensitivity. I can attest to the fact that many of the receivers I have tested in my Electronics lab do not define very weal signals,  under 1/10th of a microvolt. well.
I have done test with calibrated attenuators hooked to the output of our Calibrated HP 8640B signal generators. I have tested the following receivers Ten Tec Orion II, Ten Tec Omni 7, Icom Pro III, and several top end Yeasu transceivers. When I adjust for a signal at the very hairy edge of the receiver not being able to define it all,  of the ones listed above, have enough system grunge or microprocessor artifacts, that they do not define tones being turned on and off well. 

I can take a R 390A that I have overhauled and at the same signal level can see definable tones in the audio using  one of our Tektronix 465B scopes. It is not night and day better but it is obvious that the switched, on and off tones are cleaner. 
These test were all done in the clear with no adjacent signals at 2Khz or even 20Khz. I plan to retry the same test and would expect all of the solid state receivers to test better than the 390A with close in signals with their improved IF's and cascaded filters, However in the clear, I am amazed how well a 390A, working properly, hears very weak signals. 

I would not be surprised if the NSA would choose an R 390A for weak signal surveillance  but I guess the real question is if there are signals of interest on the HF band in these days of Sat phones, Internet and Cell phones.

73,
Glenn
DSM Labs