Vanity (question about collins R390/URR

[Charlespg]

I have a collins R390a/urr

that was given to me by a eldery vet for chistmas

I have contacted a Chuck Rippel in VA

but he said did not have the time to repair it

I am posting this because free republic has good info and maybe someone knows how I could repair this

it sat for a long time in a enclosed garage and needs cleaning as well as minor repairs( at least I hope)

[Frobenius]

Oh my, you are lucky indeed.

The R390A is a wonderful receiver (photo) and is, in fact, incredibly sensitive with a -143db noise floor which is close to the galactic noise limit.

The first one that I ever used was at NASA back during the ancient Apollo days when they were used for long haul HF/shortwave work in the event that satellite comm went down.

Many experts consider the R390A to be the finest HF receiver ever built. They were, in fact, designed for the US Spook Community and were classified TOP SECRET during the Cold War.

Whatever you do - don't hurt that radio. If it has not been powered up in a long time, I recommend that you find someone capable of working on it -- it is not a simple beast to align etc.

I have most of the operating and service manuals in electronic form (I have had my own R390A since 1997) and can forward them to you if you want - Send a private msg.

[Charlespg]

I have seen many old receivers with blown RF coils caused by a short circuit after someone powered them up to see if the radio would play.

Thats why I would rather have a expert look at it he also gave me one of these things

[USN40VET]

That is a Hammarlund HX500 ham radio transmitter, circa the 1960’s. It was a very nice transmitter,designed for single sideband voice and CW. Hammarlund was primarily known for their receivers. The Hammarlund SP600 military series receiver series was replaced by the R-390. When I was in the military, we still had one or two SP-600’s in use, in non critical applications. I also used to own a Hammarlund SP600.

Old transmitters are even more prone to damage by powering up if you are not a tech. Even if they don’t have electrical problems, a transmitter that is in working condition must be adjusted properly and connected to the proper load (dummy resistor or antenna)or smoke will likely fly. A ham license is required to connect one to an antenna.