Tube Type Military Radio Receivers

[Craig Westerman]

I have a couple of very nice EMP proof Korean war era tube type shortwave radio receivers I inherited. Does anyone know of anyone who can check to see if these radios are in spec in the Tulsa or OKC area? Anyone here into this hobby?

Thanks Craig

 

[dennishoddy]

I was stationed in Korea in the 70's. We used those old tube type radios as emergency back-up to the microwave systems. The only thing I remember is that we had several footlockers full of spare tubes to keep them running. Do you have the transmitter as well as the receiver?

 

[Craig Westerman]

Do you have the transmitter as well as the receiver?

I have several tube type receivers, but only one tube type transmitter and it doesn't work and I probably never will do anything with it. It's missing a few external parts and is over 120lbs without the receiver. Would make a fun project for someone.

http://www.rigpix.co...y/t195grc19.htm

http://www.effectnet...npa/grc-19.html

Here it is with the receiver attached.

.

 

[dennishoddy]

I've seen those!
I don't know the regulations anymore, but back in the day before one could repair, and use a transmitter, they had to get a 1st class FCC license.
I had a second class to work on the receivers, but it lapsed after I got out.

It may be different now. Just don't know.

 

[Airic]

You might seek out some HAM radio operators. Preferably one who has been around doing it for a while and might have started out with those type of units.

 

[OK Bowhunter]

I just got my ham ticket this year and what I can tell you that you can receive any frequency you want but will not be able to transmit unless you have a FCC license. There are 3 license levels that you can test for.

Technician
General
Extra

As you go up from the different licenses you get to transmit on more frequencies. With the Extra license you can transmit on all of the frequencies available for Hams. There are test prep books you can buy that has all the information you will need to pass the test. Now the good news the Technician and General test are just 35 questions from a question pool of several hundred questions. The test prep books gives you the questions and answers that will be on the test. If you have a good memory you can memorize all the questions and would be able to pass the test. Now for the really good news you no longer have to learn Morse code for any of the test. The test cost $15.00 and you can find test locations locally that have a test day once a month. The SCAREs club in Norman Oklahoma has the test I believe on the first Thursday every month and the Edmond club on the first Sat.

Now for your radios I don't know much but I believe that the tubes may be hard to find if one does not work. You will need to find out what frequencies it operates on and research on antenna designs (this is a real "black art").

If you choose to go for your Ham ticket go to www.arrl.com and http://wireless.fcc.gov/services/index.htm?job=licensing&id=amateur for information. The Oklahoma City ham club has classes to help you pass the test which have already started (I am in the Extra class now). They hold them at the OSU Tech Police Training building.

If you want more information PM I will try and help you out.

 

[drmitchgibson]

You'd do well to have someone replace all the capacitors; the non-ceramic (non-modern) caps all degrade with age. The tubes can be easily identified, but may have to be removed from their sockets to do so. Nearly all tubes are replaceable, but some can cost a lot of money.

 

[Scott Hearn]

Once upon a time I held a technicians license. Yep that means that once upon a time I knew Morse too. :72:

Those radios look just bad ass! Almost enough to get me to go back, but not quite. Building your own antenna is pretty fun when it works out and it doesn't have to cost an arm and a leg. Depends on the freq and mod type. A simple piece of wire will blow your mind sometimes with what it will do.

 

[dennishoddy]

You'd do well to have someone replace all the capacitors; the non-ceramic (non-modern) caps all degrade with age. The tubes can be easily identified, but may have to be removed from their sockets to do so. Nearly all tubes are replaceable, but some can cost a lot of money.

I'm pretty sure you are talking about electrolytic capacitors. They do have a shelf life, and in some occasions with high power systems, the caps have to be brought on line in steps. I've seen some pop explosively when hit with full voltage at the first time.
When stationed in Korea, as stated earlier, we had Microwave systems, as well as a Tropospheric scatter system. The tropo system bounced signals off of the ionosphere to distant stations. We shot to Itazuke Japan. The electrolyitics were the size of 30 gallon drums. To discharge them, we had a fiberglass pole attached to a ground. Getting within a foot would result in a sharp crack and a minature lightning bolt.
At the time the frequency was top secret. 3.5 Gig.
We get that on hand held wireless phones now.
Amazing how technology has advanced.

 

[dennishoddy]

Once upon a time I held a technicians license. Yep that means that once upon a time I knew Morse too. :72:

Those radios look just bad ass! Almost enough to get me to go back, but not quite. Building your own antenna is pretty fun when it works out and it doesn't have to cost an arm and a leg. Depends on the freq and mod type. A simple piece of wire will blow your mind sometimes with what it will do.

Me too! I have a little radio that I keep in the deer stand, and it has a shortwave feature. There are still folks transmitting Morse in short wave. I've forgot most of it but was ok back in the day. We also had to learn semafore. Communication with flags.
HaHa! I'm getting impressed with the tech folks on this site.

When in school in Ft Monmouth NJ,(home of the US Army Signal Corps) the guys in training were always talking about using different crap with their training to get radio signals.

 

[Podman]

I'm a ham and those old radios were ok in their day. But now you might find it hard to talk to anyone on am. Most hams today use ssb. Those rigs might be good for cw though. There are hams who play with mil surplus stuff and you might google some of them up and find out what they are doing with the old tube rigs.

 

[Craig Westerman]

I just got my ham ticket this year and what I can tell you that you can receive any frequency you want but will not be able to transmit unless you have a FCC license. There are 3 license levels that you can test for.

Technician
General
Extra

As you go up from the different licenses you get to transmit on more frequencies. With the Extra license you can transmit on all of the frequencies available for Hams. There are test prep books you can buy that has all the information you will need to pass the test. Now the good news the Technician and General test are just 35 questions from a question pool of several hundred questions. The test prep books gives you the questions and answers that will be on the test. If you have a good memory you can memorize all the questions and would be able to pass the test. Now for the really good news you no longer have to learn Morse code for any of the test. The test cost $15.00 and you can find test locations locally that have a test day once a month. The SCAREs club in Norman Oklahoma has the test I believe on the first Thursday every month and the Edmond club on the first Sat.

Now for your radios I don't know much but I believe that the tubes may be hard to find if one does not work. You will need to find out what frequencies it operates on and research on antenna designs (this is a real "black art").

If you choose to go for your Ham ticket go to www.arrl.com and http://wireless.fcc....sing&id=amateur for information. The Oklahoma City ham club has classes to help you pass the test which have already started (I am in the Extra class now). They hold them at the OSU Tech Police Training building.

If you want more information PM I will try and help you out.

Thanks. I've had my General ticket just over a year now.

.

 

[Craig Westerman]

I just found an old radio tech in Broken Arrow that is into these old tube type receivers. He has offered to help me go through them. I have been collecting backup tubes for these for a while now and should be good to go. There isn't but just a few electrolytic capacitors in these units. I think one has had them replaced.

Here is some images of the receiver by itself.

 

[Craig Westerman]

I also own a pair of these bad boys. One has been fully restored. In 1968 you could buy them for $1700. Over $11,000 in today's dollars.

http://web.archive.org/web/20070630164553im_/http://www.r390a.com/assets/images/collins7_copy.JPG

The R-390A was deployed to most branches of the US military and remained in general use through the 1980s. The last major update to its documentation was in 1984. As the military procured newer receivers, many R-390As were released to surplus while others were destroyed. Some receivers were retained by the services, however, when they found that the R-390A's vacuum tube circuitry could easily survive an electromagnetic pulse. There are reports, possibly apocryphal, that R-390A receivers are still in use aboard U. S. Navy submarines since the receiver can withstand the strong radio frequency fields found aboard ship.

Many of the R-390As that exist today are in the hands of vintage amateur radio collectors and amateur radio operators who contend that few modern solid state communications receivers can equal its performance. There is a wealth of information, both printed and electronic, devoted to R-390A restoration and maintenance, as the R-390A is widely considered an example of the best of vacuum tube technology.

http://www.r-390a.net/faq-overview.htm

 

[dennishoddy]

Cool!

 

[twobravo]

I enjoyed the pictures in this thread. My wife and I both have had our amateur radio licenses for several years now. I'm a lifetime member of the Broken Arrow Amateur Radio Club as well. I think I know why might have helped go through those old military rigs. Cool stuff!

 

[Iggie]

Those are awsome! I have really wanted to get into ham radio! Its awsome that you are tring to get them working again.