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TonyDuell · 2nd Nov 2019, 5:04 pm

Would a reverse-engineered circuit of the Tester 301B (alas without the charger as I don't have one either) be any use?

The Tester 301B has an internal NiCd battery of, IIRC, 12 cells. The charger circuitry in the unit starts with a step-up SMPSU circuit so it looks like you could charge it from a 12V input. I've never tried, the cells in mine are totally dead. The XLR connector on the Tester 301B has 3 pins which are : common -ve, +ve input for the charger, +ve input to run the unit without using the internal battery.

You can power a Tester 301B from 12V fed on the correct 2 pins of the XLR connector. That will work even if the internal NiCd cells are totally dead.

2nd Nov 2019, 5:04 pm	#2
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,222	Re: "Rectifier" 161A/162A Would a reverse-engineered circuit of the Tester 301B (alas without the charger as I don't have one either) be any use? The Tester 301B has an internal NiCd battery of, IIRC, 12 cells. The charger circuitry in the unit starts with a step-up SMPSU circuit so it looks like you could charge it from a 12V input. I've never tried, the cells in mine are totally dead. The XLR connector on the Tester 301B has 3 pins which are : common -ve, +ve input for the charger, +ve input to run the unit without using the internal battery. You can power a Tester 301B from 12V fed on the correct 2 pins of the XLR connector. That will work even if the internal NiCd cells are totally dead.