Avo mk2 valve tester - UK Vintage Radio Repair and Restoration Discussion Forum

Renato71 · 24th Jan 2020, 7:10 am

Hi, I have fixed an avo mk2. I have measured many valves, if they are with few amperes, type ecc83, everything seems to work. If I try valves that should produce a lot of amperes, el36 and El 34, it doesn't measure correctly, all the valves indicate few amps. In the repair I replaced all the diodes with BYT52M, the ea50 with a new one, the capacitors, some resistors. I added two diodes and a 100uf capacitor to the milliamperometer. When measuring without valve all voltages are correct, the digital tester on the back also indicates the correct current. Ideas? Thanks Renato, from Italy.

Renato71 · 26th Jan 2020, 2:31 pm

Resolved! I found the problem, it was a bad contact in the "CIRCUIT SELECTOR". Finally everything works.

Kevin Hoyland · 27th Jan 2020, 8:45 am

Hello.
I am pleased that you have worked it out. I have a mk2 and enjoy using it.

Regards
Kevin.

24th Jan 2020, 7:10 am	#1
Renato71 Diode Join Date: Dec 2019 Location: Siena, Italia. Posts: 2	Avo mk2 valve tester Hi, I have fixed an avo mk2. I have measured many valves, if they are with few amperes, type ecc83, everything seems to work. If I try valves that should produce a lot of amperes, el36 and El 34, it doesn't measure correctly, all the valves indicate few amps. In the repair I replaced all the diodes with BYT52M, the ea50 with a new one, the capacitors, some resistors. I added two diodes and a 100uf capacitor to the milliamperometer. When measuring without valve all voltages are correct, the digital tester on the back also indicates the correct current. Ideas? Thanks Renato, from Italy.

26th Jan 2020, 2:31 pm	#2
Renato71 Diode Join Date: Dec 2019 Location: Siena, Italia. Posts: 2	Re: Avo mk2 valve tester Resolved! I found the problem, it was a bad contact in the "CIRCUIT SELECTOR". Finally everything works.

27th Jan 2020, 8:45 am	#3
Kevin Hoyland Heptode Join Date: Feb 2009 Location: Rotherham, South Yorkshire, UK. Posts: 559	Re: Avo mk2 valve tester Hello. I am pleased that you have worked it out. I have a mk2 and enjoy using it. Regards Kevin.