原创 A vacuum tube radio that needs some love

All I can express is that I am flabbergasted. In fact, I would go so far to say that it's rare indeed for my flabber to be quite so gasted. I was sitting here in my office slaving away over a hot keyboard when my chum Charles Fulks unexpectedly breezed in.

Charles (he lets me call him that) leads the FPGA development group for Intuitive Research and Technology just down the road from me. I shared the stage with Charles and RC Cofer at this year's EE Live! Conference and Exhibition.

You can only imagine my surprise to discover that Charles had brought me a little something. There's an old saying that goes something like "Beware of Geeks bearing gifts," but I certainly wasn't going to look this gift horse in the mouth, because this little beauty was a vacuum tube radio from the early 1940s.

Amazingly enough, I have the perfect spot for it. The photo below shows the bay outside my office. The comfy chair and ottoman in the foreground allow one to take a few minutes' break now and then. Standing against the wall is a 100-plus-year-old wooden chest, upon which rests the frame for my ongoing mosaic project -- and now my beautiful vacuum tube radio.

In case you were wondering, this bay is where I seem to end up storing the furniture my wife doesn't want me to keep in the house (LOL). On the left side of the above picture, you can see my office door. (Mine is the one with the dragon on the far wall.)

The radio is a Grundig 5088. (I need to see if I can find the circuit diagrams somewhere.) This is an AM radio with multiple ferrite rods for long-wave, medium-wave, and short-wave reception.

Charles says that, when he acquired this little rascal several years ago, he was told that it did work, though he's never tried it himself. As soon as I get a free moment, I'm going to power it up, but I will have a fire extinguisher standing by, just in case.

I would love to have this radio playing in the background in our bay. Something about the sound that comes out of a vacuum tube radio makes you want to use words like "smooth," "sensuous," "robust," and "rotund."

Of course, chances are that this little scamp won't fire up the first time. It wouldn't surprise me if we needed to replace the paper capacitors and suchlike. The problem will come with the vacuum tubes. I'm reasonably sure I will be able to pick up anything I need at the Huntsville Hamfest in August (subject of a blog post last year). The real trick is to determine which tubes need replacing.

But where can one find someone who knows how to diagnose and debug problems with vacuum tube-based systems these days? Well, you could have knocked me down with a fishwife (much more effective than feathers) when I discovered that my chum Ivan in the next bay is a diva with vacuum tubes.

Actually, this really shouldn't surprise me by now. Ivan is one of the cleverest guys I know. (Yes, I'm buttering him up; I want him to fix my radio.) When I called Ivan over to see my new acquisition, he foolishly informed me that he used to repair radios and suchlike.

Upon further questioning, I discovered that Ivan that was in an accredited trade school while in high school (he crammed standard classes and electronics classes in alternating weeks), and that this involved repairing electronic systems. While in the Air Force, he focused on maintaining and repairing electronic systems. After leaving the Air Force, to supplement his income at college, he worked at Magnavox repairing everything that came his way: CB radios, record players, AM/FM radios, TVs, laser disk players, alarm systems, audio amplifiers, PA systems, walkie-talkies -- the list goes on.

Do you ever get the impression that some things were just meant to be? I have a vacuum tube radio that needs some love, but I don't have the skill to treat it with the respect it deserves. Ivan has skill oozing out of his fingertips, but no vacuum tube radio to unleash it on. It's like a marriage made in heaven (LOL).