Friday, August 02, 2019

Poignant Salvage

     I spent yesterday on the early stages of removing a two thousand Watt analog transmitter I installed nearly thirty years ago.  It was a pretty good little transmitter; I shepherded it through a major channel change, through the original manufacturer changing hands and then passing the device-specific parts replacement/repair off to a third-party, and moving from brand-new to rebuilt transmitting tubes.  (Kennetron, by the way, is the last of the independent tube rebuilders and did very good work for us, at about half the price of new).

     The OEM and the brand-specific aftermarket guys are gone now, and the transmitter itself has been out of service for nearly a decade.  But it wasn't worth removing until we needed the space, which we do.  What I'm doing is disconnecting wiring and readying up the transmitter and related equipment; it's on the very last patch of the original gray and green floor tile* in the building, which will require a specialist to remove.

     It's something of a trip through old memories, from the time I was trying to figure  out a mess of wiring in the poorly-lit rack next to it and, tugging on a wire, launched a very dead bird right past my face to the day I was retuning it and realized the factory tech who'd said, "Oh, the solid-state amplifiers are wideband, shouldn't have to touch those" had no idea I was moving the thing from one end of the UHF band to the middle and I was, in fact, going to have to retune the entire transmitter all the way from the low-level stages to the high-power output.  That turned out well, one of my earliest successes at keeping the little secondary station running using mostly what we had on hand or could dig out of dumpster-bound storage.

     Some of the parts are destined for salvage but most of it will just join that same "e-waste" storage, waiting for the recycler.
* I wanted to keep the checkerboard floor pattern when we redid the building interior, which made the architect's industrial designer snicker.  Nope, we got a nice, bland shades-of-gray pattern.  Drop a machine screw and it blends in invisibly.   


Fuzzy Curmudgeon said...

That industrial designer should be forced to look for dropped machine screws on his hands and knees. He'll recognize the error of his ways as soon as his knee finds one.

pigpen51 said...


It only takes one. I am not an electronics technician, but I am an old ham radio operator. I built a Heathkit receiver once, and stuck a machine screw into my knee all the way to the end of the threads. It was a short one, but hurt like crazy, and bled like a stuck pig, when I pulled it out.

I never knew that there were companies who rebuilt tubes, either. The last I ever knew, most of the tubes were coming from Russia, or someplace like that.

Roberta, it sounds like you have kept that place going for a long time. I spent the better part of my life in the same place too. I hope that your employer appreciates what you do for them. Sometimes, it is not just about money, but respect.

Paul said...

Long as you don't take it home with you.

JimBob said...

2KW on 2 Meters! We don't need no steenking repeater!

Roberta X said...

Jimbob, the tube and power supplies would do it; the cavities, well, 440 would be a better bet and I'm not too sure about even that.

This was my "dollhouse" transmitter, a quarter-scale version of the big tube rig; the petite integrated tube socket and cavity wasn't field-rebuildable past replacing the tube socket finger stock. The final amplifiers were electricially identical to the main channel and kind of fun to tune. None of that motor and leadscrew stuff, you were sliding the various elements back and forth directly, with a typical double-tuned broadband output that gives you four controls -- primary and secondary tuning, coupling and loading. It takes a sweep generator and spectrum analyzer to tune it.

BTW, the little tubes were about $3K to rebuild -- new ones were over $5K!