11c Power Supply Capacitor

[Lunn Sawyer]

I suspect that my power supply cap is bad on my HP-11c. I would like to replace it but am not sure of its value. It has 2 numbers legible on it "22" and "10". Is it correct to assume that this means "22pF 10%". Does anybody know?

Thanks Lunn

[David Smith]

It would be 22 microfarad (uF) at 10 volts.

[Nelson M. Sicuro (Brazil)]

It is 22uF (micro-farad) x 10V (volts), the tolerance doesn't matter much, as is a "backup" capacitor (to preserve memory when changing batteries)

The capacitor voltage must be higher than 5V. You can find some 22uF x 6.3V or even 47uF x 6.3V (more time to change batteries) to replace it.

If you can get the tantalum ones, they are smaller and more durable.

Good luck!

Nelson