Thread: Wireless Set 19
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Old 19-09-11, 23:11
Ralph Volkert Ralph Volkert is offline
Communications Field tech
 
Join Date: Mar 2008
Location: Latchford, Ontario, Canada
Posts: 142
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The problem with OLD electronic equipment is that the capacitors or condensors as they were called back then were consctucted of strips of paper and foil. Aditional insulating material (dialectric/electrolyte) similar to a sticky varnish was applied to prevent arcing and shorting. It was then rolled up into a tube. Think of those flypaper strips hanging from the ceiling.

Because they were of paper and card board construction they could dry out because of outgassing. A sudden application of full power can cause the voltage to arc through the cracks and pinholes of the dried out electrolyte across the foil plates causing a short cicuit, generating heat and pressure! You will hear a very brief high pitched whistle just before you hear the BANG!

By reforming the the condensors you power up very slowly, increasing the voltage slowly so as to allow the electrolyte to warm up slowly, soften and "heal" the pinholes and cracks. Did you notice the words Slowly! I have known people to take 12-24 hours to do this. There is never any guarantee.

Any componant showing heat damage should not be trusted at all. They were baking themselves already. If you do try to power up these old electronics wear safty glasses and be preppared to kill the power immediately.

Dont forget how old these things really are! A lot of these old componants have drifted in value and so can be so far off spec that they wont tune or function properly.

Dont forget that radium was used to allow the front of the sets to glow in the dark. No sanding of the frant panel should be done. And I would be cautious about letting small children play with the set.
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Ralph Volkert

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