Thread: Hunts CRB3
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Old 25th Sep 2020, 12:25 pm   #91
JayBee66
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Join Date: Nov 2015
Location: Kilkenny, Ireland
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Default Re: Hunts CRB3

Hello Alistair

I saw your updated manual on http://golbornevintageradio.co.uk/ posted 13 Jun 2020. Will you be updating this further?

Thanks for your hard work.

Quote:
Originally Posted by Alistair D View Post
There is an easy way to measure the leakage in that capacitor or any externally connected cap.

This is a draft of an entry in an updated manual I am slowly compiling. It explains the method

CAPACITOR REFORMING
The CRB3 can also be used to reform electrolytic capacitors.
Select the voltage you want to start the reforming process at and INS. As the reforming progresses the neon should flash less and less often. Repeat the process at higher voltages until the capacitor’s maximum voltage is achieved. Due to there being a neon in the current path the actual voltage applied to the capacitor will be less than selected. As a final stage of reforming select LEAK or LEAK HIGH CAP for a short period of time. Connecting a high impedance voltmeter between the CAPACITY negative and EARTH terminals will give an indication of the leakage current. In the LEAK setting 1 volt equates to approximately 15uA leakage current. In LEAK HIGH CAP 1 volt equates to approximately 30uA.
Stubborn capacitors may benefit from short spells on the LEAK or LEAK HIGH CAP settings at the start of reforming. Figure 16 shows the active circuitry for these processes.

Al
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