Repairing old Radio Shack equipment

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somebody bid on it. After the first bit, buy-it-now goes away.
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On Sat, 28 Feb 2009 21:01:36 -0600, AZ Nomad

I get it. That sounds vaguely familiar. Thanks.
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All those symptoms add up to a high probability of a bad lead, probably the black one. Hold the plugs and pull on the wire. If you see any stretching of the insulation, that's where the break is at. Red
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The old Simpson meters (c. 1960) weren't particulaly accurate. Their accuracy was expressed as "Percent of full scale."
Thus, if you measured a nominal 10 volts on the 100 volt scale, your reading could be up to 1 volt in error with a 1% full scale accuracy meter. Use a 2% meter (Most Simpsons were 2%), and you can be off by 20% on a 10 volt measurement on the wrong scale.
I didn't take that seriously until I had to make a LOT of measurements on microwave diodes and found that my "simpson" meter readings were so inaccurate as to make my data worthless.
You can pick up a digital meter from Harbor Freight for less than $5 that's more accurate than any "analog" meter.
You might want to keep the old meter around as a curiosity (or in case you fear that WWIII will fry everything electronics) but except for "fun" purposes, they aren't worth fixing.
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We used a lot of them for maintenance on various pieces of government equipment. They were accurate enough for what we were using them for. Filiment voltage...6.2v...close enough for me...anode voltage 150v...close enough for government work :)

Like many old timers, I cut my teeth on analog meters, and I still prefer them to digital meters. When I'm working on house wiring, I usually use some digital clamp on thing made for electricians. But when I'm working on my rf/audio gear, I'll take the analog meter any day.
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the DMMs from Harbor Freight are only 1 megohm input Z. any good DMM is at least 10 MegR. And the first one I had measured a 1.5V alkaline cell at 1.8 volts. I would NOT rely on them for accuracy.
--
Jim Yanik
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I know where I can get you 9Megs cheap.

I'll give you a good price for those 0.3 volts, cash on the barrelhead.

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Jim Yanik wrote:

Too high input Z is some times not prefered. Unless you work on digital circuits exclusive. For that I use scope.
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Zootal wrote:

RS never sold a meter worth fixing. Just chuck it if you can find a problem inside like worn out battery or fuse. I saw a digital meter with clamp on AC current probe for 9.99 in a local store. My meters are Fluke, Amprobe, and Simpson.
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RS hasn't sold much of *anything* worth fixing for a very long time. I stopped buying Radio Shack products years ago because I got tired of them breaking or otherwise going bad. A long time ago Made In Japan products used to have a bad reputation (ok, I'm dating myself). Now it's the made in China stuff, which is just about everything in Radio Shack, is even worse.
I took the thing apart, and found two pots I need to check. I have a half-dozen meters already, so I think I'll put this back on a shelf with the rest of the stuff I don't have time to sort through.
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With chinese stuff, it depends on the engineering. The engineering of the product and of the manufacturing process is rarely chinese.
Radio shack like the lipstickonapig approach. The crappiest products, but with a pretty case.
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They haven't made anything worth fixing?
Try 22-174B and 22-220
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