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Old 25th Aug 2011, 7:34 pm   #4
paulsherwin
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Location: Oxford, UK
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Default Re: That Capacitor?

Although Geof is correct strictly speaking, it usually means the capacitor feeding the output valve control grid in a radio or class A amplifier.

It's referred to like that because it's so notorious in typical old valve electronics. Even a small leak will put significant positive volts on the grid, causing the valve to pass lots of current. This can wreck the valve and the output transformer.

That Capacitor is a change on sight item if it's a waxie or Mouldseal. With ceramic or plastic film caps you can check the grid voltage and replace if necessary.
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