原创 Bringing an organ back to life

It was in 1970 when I was 15 years old. I decided that I wanted a job working on electronics. I visited TV shops and such, and no one would hire me. My last stop was at Hoot Gibson's music store, where the owner (Hoot himself) made an interesting proposition: If I could fix a broken organ he had in his shop, he'd give me a job.

The organ was acquired as a tradein, sight unseen. When Hoot picked it up, he realised that the owner must have attempted to fix the pedal section and left it disassembled and with all of the wires cut. The organ was a vacuum-tube Thomas, which was not a brand that Hoot carried.

When I first saw the shape it was in, the likelihood that I could fix it didn't look good. But I really wanted the job, and it looked like a challenge, so I took him up on his proposition and began working on it. Besides, no one else had offered me the chance to do anything else.

First off, I called Thomas and ordered replacement actuators for the pedals, because they seemed to have been the real problem. When the actuators came, they actually didn't fit. It appeared that along the way Thomas had changed the design. The new actuators were much better, so after drilling new holes in the pedals, I was able to mechanically reassemble the pedals, and it looked good.

Next I had to reconnect all those cut wires. It didn't take too long to figure out how they likely were meant to be connected, so I hooked them up. I still didn't have a schematic, but I turned the organ on, and the pedals were working. That was the good news. The bad news was the organ had all kinds of other problems.

By then I had spent a couple of Saturdays working on the organ and had made good progress. That was enough for Hoot, so he took me. Since the Thomas was going to be a long-term project, he assigned me some other units to work on. He also had enough confidence in me to pay for a schematic and a special contact cleaner that Thomas offered for $50. That cleaner was like brown goo, which seemed pretty strange, but it worked on the contacts.

One of the problems I encountered on the Thomas was that its vibrato oscillator wasn't oscillating. I even replaced the tube, and it didn't help. Looking at the schematic, I noticed that the oscillator had no cathode resistor bypass capacitor, so I added one. That did the trick.

Tuning the Thomas was painful. There was an oscillator per key—no top octave generators in those days and no dividers in this design. There was just an analogue oscillator per key and an inductor shared by three adjacent oscillators. These inductors could be adjusted as kind of a gross adjustment for the three oscillators. Then each oscillator could be adjusted separately. The thing is that adjusting one oscillator also affected the other two. Eventually, they would converge on a good tuning, but it took many iterations to tune every group of three oscillators. Note to self at the time: Don't forget to let the organ get to a stable operating temperature before tuning it.

Hoot normally paid $7.00 for each organ repaired, regardless of the time spent. To my knowledge, he only ever paid more for this Thomas. He gave me $50 with the understanding that, after he sold that organ, I would make a house call if the new owner ever had a problem. I did get to make that house call, but only to clean contacts. I still had the magic cleaning goo, of course, so that was easy. Hoot, being the consummate salesman that he was, soon got the owner to upgrade to something better, and the Thomas was never heard from again.

By the time I was 17, Hoot trusted me with the store's van, so I could make house calls. When there was a factory-mandated service update, the use of the van allowed me to do many of those updates. The factory paid me more for installing those simple updates than Hoot paid me for repairs, so I really liked that work.

By taking the gamble that I could fix that hopeless organ, I got a job and a lot of experience. Hoot had nothing to lose, while I had everything to gain. I may not have been paid much, but I learned quite a lot.

Shhh. Don't tell anyone, because it was probably against Illinois law for anyone under 18 to be doing that kind of work at the time. So maybe Hoot did have something to lose, but I didn't tell him.

This article was submitted by Mark Rustad, Networking Division, Intel Corporation, as part of Frankenstein's Fix, a design contest hosted by EE Times (US).