Spare Parts- Old TV's

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I used to run a recording studio. I had some old Ampex vacuum tube equipment I was restoring. Soon I became immersed in such things and began to need some spare parts. Electronic stores would seldom have things like, say, mica tuning capacitors. But there were old TV's aplenty, and I began to scavange these. I think I disassembled 15 or 20 old tube sets and some other bizzare oddities such as an old foot x-ray machine from a shoe store. (people actually would put their foot under it and wiggle their toes on the glowing green screen.) I also redid an old damaged Hewlett Packard vacuum tube/transistor hybrid oscilloscope. Boy was the lady shocked when I called HP and asked for a schematic!

Old TV sets are a gold mine of obscure or specialised parts. Here is a partial list of the goodies I got:

Tubes, all types and sizes

Tube sockets, bakelite AND ceramic!

Tuning varactors, coils

High wattage resisitors and capacitors

High current potentiometers

Electrolytics (watch out!)

Rare ceramic capacitors (look like little dominoes) mica caps

RF amplifier tubes (one was a push-pull AB all in one tube, had something like 17 leads) mercury-filled tubes

Switches and relays

Connectors of all types and sizes

High power and germanium transistors

Some sets had seperate boards for color amplifiers etc. that can be removed as a unit

Old remotes worked on high frequency sound so some sets have supersonic detectors!

These kinds of parts, especially the high power and RF oriented, will be especially useful for radio rigs in the event parts are hard to obtain.

I learned how to desolder and disassemble things without damaging them. I came to some conclusions about technology:

- Accumulations of dust and grut on circuits causes fires. Most of the sets I consumed had fire damage. A couple came with stories of panic and heroism during the Super Bowl or some other significant show. Keep 'em clean!

- Things now use a lot less power and generate a lot less heat (see Fires above.) This is very good.

- Printed circuit boards are very good. Nothing like sorting through old spiderwork electronics and busting all your knuckles teaches you to love PC boards.

- Vacuum tubes can take all sorts of abuse, even overvoltages that would totally destroy IC electronics. They are also more elegant, refined, aesthetic and interesting than semiconductors. Unfortunately they are inferior in too many ways to survive except when you need HIGH POWER!!!!!

- There is a lot of antique electronics and therefore antique knowlege that is falling out of use. This may or may not be good

- IC chips are the best but bad in one way- they fry, they die. On old worn out tubes, you could reverse the voltages on them to 'burn back', literally force the oxides off the plate back on to the cathode! This would restore them for a while. The little chippies resemble bugs in that they both look like and must be reproduced like insects. This is the vulnerability of things and the result of a throwaway world.

- Back then, Men were Men and Voltages were High. Many of these old sets were downright dangerous.

- Electric shocks are VERY BAD> ouch.

- We waste huge volumes of valuable material in this society.

_ If you use a lot of big words when you go ask for old broken TV sets, you will be thought strange and may have difficulty getting dates in small towns.

There are other types of electronics out there to recycle. But old, half-burnt sets from the early '60s with pretentious veneer woodwork encrusted with spilt beer and cigarette tar hold a special place in my heart.

WARNING!!! On many if not most sets there are one or more LARGE can capacitors which provide the voltage burst to start the picture tube. Generally they are located in the back behind the picture tube. These sometimes hold a charge for YEARS. I always short them out with a long, insulated handle screwdriver. I have lost several screwdrivers this way. Don't assume no spark means no charge (that bit me once). Microwave ovens have similar cans. Beware!

Don't sue me if you go and do this and get hurt. I am a known y2k nutcase, beware.

I can only wonder what kinds of Rube Goldberg contraptions evolve as patch is patched on patch. It could be very wierd.

-- Forrest Covington (theforrest@mindspring.com), September 18, 1999

Answers

Forrest - this reminds me of Newt Gingrich, I believe, giving speeches about how antiquated federal equipment was by waiving about tubes. These were to be replaced by the tiny chips he then flourished. I thought this had to do with air traffic control for some reason. This was only a few years back. If they had stuck with tubes would they be compliant? Things that make ya go hummmmmm.

You can come visit my attic anytime. It is a boneyard of broken appliances and computers. Just didn't seem right to chuck em in the dump. What are you supposed to do with stuff like that, anyway?

-- marsh (armstrng@sisqtel.net), September 18, 1999.


I used to scavenge the shunt capacitor (that "can" Forrest mentioned) and flyback coil (which connects to the back of the picture tube via a fat, usually red, wire and will shock the piss out of you if you don't discharge it first) as well as the horizontal drive transistor out of old TV sets and make a simple, mean HV power supply out of them. Usually good for 1/4" to 1/2" arc of purple zap-on-demand. Made one HELL of an electric-fence. [chuckle]

There's a lot inside an old TV that can do you in, from simple zap- flinch-curse level to potent enough to blow off a fingertip (yes I - have- seen that happen! Fellow brushed across the HV shunt capacitor and it blew the last half inch off his middle finger simply form the stored energy discharging through his flesh.) so NEVER poke and prod any wiring unless you have discharged everything first by shorting its terminals with a screwdriver, et al, sporting a properly insulated handle.

But...

If you know what to do with these parts, you can make some interesting stuff like a high-voltage electrocuter wand that'd - really- get an assailant's attention. ;-)

That guy's on the loose again, and people call him...

-- OddOne (mocklamer_1999@yahoo.com), September 18, 1999.


Marsh- that stuff could be a goldmine later. (That's what everybody thinks who has a house or a garage full of junk.)

Yeppir, those voltages will blow off fingers. No doubt! I once destroyed a foot long screwdriver with a 3/8 steel shaft on one of those monsters.

Once I also thought that peewee current levels were no big deal. Wrongo! Got a nasty zap on 100 milliamps @ 86v.

Electronics are fun and fascinating but a paranoid attitude is safest.

-- Forrest Covington (theforrest@mindspring.com), September 19, 1999.


Packrats will rule...

watchin' the strange man...

The Dog

-- Dog (Desert Dog@-sand.com), September 20, 1999.


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