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4th of July in 555 2nd IF can
#14

Do you have a schematic? Schematics often say what color wire is connected through the transformer windings to whatever other color of wire. Sometimes the resistance across the coils is also listed. Find those wires that are supposed to be connected and measure ohms between them. Resistance is usually in the low ohms (less than 5 or 10, sometimes less than 1.)

High resistance is a bad sign if the schematic shows connection. Zero resistance is also a bad sign. Your ohm meter will probably show .3 or .4 ohms with the leads shorted, so you should subtract that from the reading when measuring low resistance.

Then measure across leads that are not supposed to be connected. They should read completely open, and your meter should read exactly as it does when not connected to anything. Any resistance at all means a short, and is a bad sign.

In the picture some of the tiny black wires look like they have crumbling insulation on them. If there is any chance of them touching anything, unsolder one end of them and put a sleeve on them, very carefully. That'll make them better than new. The primary side wires have high voltage on them. They'll make sparks if they touch the can, and that will likely burn out some tiny wires you can't replace.

I've never done it myself, but I've heard of people painting little wires like that with some stuff made for the purpose instead of sleeving. I can't remember the name of it.

John Honeycutt


Messages In This Thread
4th of July in 555 2nd IF can - by OldRestorer - 04-27-2014, 03:45 PM
RE: 4th of July in 555 2nd IF can - by Warren - 04-27-2014, 04:49 PM
RE: 4th of July in 555 2nd IF can - by TA Forbes - 04-27-2014, 07:38 PM
RE: 4th of July in 555 2nd IF can - by morzh - 04-27-2014, 07:46 PM
RE: 4th of July in 555 2nd IF can - by codefox1 - 04-28-2014, 05:57 PM
RE: 4th of July in 555 2nd IF can - by Mondial - 04-30-2014, 11:46 AM
RE: 4th of July in 555 2nd IF can - by codefox1 - 04-30-2014, 12:34 PM
RE: 4th of July in 555 2nd IF can - by Raleigh - 05-05-2014, 07:36 PM



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