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Old 28th Feb 2021, 11:13 am   #1
stevehertz
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Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,835
Default Capacitor voltage?

For use in a tight space in a Pye M78F that I'm restoring (see other thread in wireless section) I want to use this 0.01uF cap (marked '103' = 10,000pF = 0.01uF)). The problem is, it doesn't show a voltage rating. Does anyone know what it's voltage rating is, or is likely to be? Its position in the circuit is C7, HT feed decoupling. See circuit diagram. My HT into the set will be 74V. But that is dropped via R12 ((680ohms) and R2 (10K) to get to C7. Trader valve voltage table also shown - bear in mind the voltages quoted are based on the HT being 67.5V.

Is this cap suitable?

Otherwise it's not the end of the world, I'm pretty sure I may be able to find a cap that I can shoe horn into the very limited space but the cap I'm talking about would be ideal size wise. The set was build layer by layer, and there's a number of short wires etc lying over the cap in question that will be a pain to unhook or even replace. It's all very tight, like performing open heart surgery on a mouse. Originally the cap would have been fitted first, then those obstructive wires.
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