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Old 29th Jun 2017, 11:13 am   #8
Boater Sam
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Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
Default Re: Cossor Melody Maker 494 A.C. Valve radio

Many of the old paper wax capacitors have a band on one end. That is the outer foil and would have been connected to the low potential connection in the circuit. This is thought by many to reduce hum levels.

Most modern foil capacitors are not so marked, but you can find the outer foil ends if using wound foil capacitors. This is done by connecting one end to a 'scope and holding the capacitor in the fingers, the 50Hz so picked up is of greater amplitude when the outer foil end is connected.
But as has been said, modern parts unless electrolytics are not deliberately polarised.
Sam.
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