Heathkit GR 21 FM Radio
 

I found one of these at the thrift store yesterday. Any ideas? It is tube, and has one aux input, and one max output. Here is a link to an ad I found on the net. http://www.somerset.net/arm/radio_pi...th_gr21_ad.jpg. You can expand the add to read it. The Radio works great. Nice cosmetics also. I posted in the Tube Forum, but did not get any responses. Probably because I did not ask.

The MPX (multiplex) output can be used with the matching amplified speaker or with a multiplex adaptor that supplies stereo line level outputs for a pre-amp or integrated amp. The Heathkit stuff is almost always excellent, providing the kit builder was capable of following directions and good with a soldering iron.

I did not see any signs of sloppiness in the assembly of the unit. It has an Eye Tube for Tuning. I wonder if I can hook a CDP up to the Aux Input. I would need a something to combine the connections into one. I know nothing about tubes. One day I guess I will find a nice tube amp.

A simple Y adaptor is all you need. Two RCA Jacks to one RCA plug. You can get them at Parts Express or Rat Shack.

How the heck long do tubes last? These are original. The add says 7 tubes. I only see three. But I have only taken the back off to brush the dust out. It has a switch on the back for Normal, and Aux. Also has a switched plug in connection. Has a nice wood cabinet also. Really neat, and that is what made me buy it.

Just checking the unit again, I see all seven tubes. They are in a metal housing.

Tubes can last a very, very long time depending on what their function is and how many hours are on them. RF and pre-amp tubes generally have long lives, whereas output tubes and rectifers have shorter lives. Their are metal tubes, but you are probably seeing shields placed over the glass envelopes.

Yes. Shields over Glass Tubes. What do you think this unit is worth Celt? Or should I ask this question in Dollars and Sense?

I connected a mono 1/8 splitter to the aux input, and connected a CDP but static and almost non audible sound of the music from the CDP. Probably the aux input is not strong enough to receive the CDP's Signal. Or just barely. I probably have to use a preamp to use the aux. The splitter stuck out a little from the input. I do not want to mess with this unit to much and damage it. Any suggestions on the aux input are welcome.

It's worth or value a D&S question. Aux input should accomodate a line level source. The intention back then was probably a TT with a crystal cartridge which had fairly high output levels of 2-3 volts. Maybe the selector switch is dirty or tarnished. Probably needs DeOxit, especially if you are hearing static or it being intermittent.