AVO 2 Panel - restoration ideas? - UK Vintage Radio Repair and Restoration Discussion Forum

les24preludes · 11th Jun 2021, 1:20 pm

I have an AVO 2 Panel tester which doesn't work. Don't know why - meter lost magnetism or what. Before I open up the meter part I'm wondering what's the simplest fix. One easy solution it seems would be to use the panel part and make a basic emissions tester from scratch to connect to it. If so, what's the 9 pin connector - a B9G? Diameter of pins is 26mm in a straight circle.

Any ideas for a basic emissions tester, circuit etc? I have bench supplies at 30v/2A or 15v/4A for the heaters and grid bias. I could rig up a basic HT and use a 150v glow tube for instance. I'd use a multimeter to read off results. I only intend to measure smaller input tubes and maybe some outputs like 6L6, 6V6 etc. Nothing exotic or bigger.

Or if I open up the Meter unit, can I substitute a couple of test points for the meter and use a multimeter instead?

ms660 · 11th Jun 2021, 1:49 pm

Quote:

Originally Posted by les24preludes

what's the 9 pin connector

B9 so far as I know.

Lawrence.

les24preludes · 11th Jun 2021, 4:05 pm

Thanks - I've ordered a B9 socket. Now I need to figure out an easy build for a way to test emissions.

ideas?

Electronpusher0 · 12th Jun 2021, 6:50 am

The AVO 2 panel has the same horseshoe magnet as the AVO 7 and seems to suffer from loss of magnetism. I have tried re-magnetising the magnet and replacing it with a neobium magnet.
I reported my adventures here:

https://www.vintage-radio.net/forum/...d.php?t=165159

I have also breadboarded a digital meter replacement for the AVO 2 panel using peak detection and sample and hold, this works well on the bench on simulation, I am trying to find the main panel from a 2 panel AVO tester with a duff meter to fit it into.

see here:

https://www.vintage-radio.net/forum/...7&postcount=14

Peter

11th Jun 2021, 1:20 pm	#1
les24preludes Triode Join Date: Feb 2021 Location: London, UK Posts: 10	AVO 2 Panel - restoration ideas? I have an AVO 2 Panel tester which doesn't work. Don't know why - meter lost magnetism or what. Before I open up the meter part I'm wondering what's the simplest fix. One easy solution it seems would be to use the panel part and make a basic emissions tester from scratch to connect to it. If so, what's the 9 pin connector - a B9G? Diameter of pins is 26mm in a straight circle. Any ideas for a basic emissions tester, circuit etc? I have bench supplies at 30v/2A or 15v/4A for the heaters and grid bias. I could rig up a basic HT and use a 150v glow tube for instance. I'd use a multimeter to read off results. I only intend to measure smaller input tubes and maybe some outputs like 6L6, 6V6 etc. Nothing exotic or bigger. Or if I open up the Meter unit, can I substitute a couple of test points for the meter and use a multimeter instead?

11th Jun 2021, 4:05 pm	#3
les24preludes Triode Join Date: Feb 2021 Location: London, UK Posts: 10	Re: AVO 2 Panel - restoration ideas? Thanks - I've ordered a B9 socket. Now I need to figure out an easy build for a way to test emissions. ideas?

12th Jun 2021, 6:50 am	#4
Electronpusher0 Nonode Join Date: Jun 2016 Location: Bognor Regis, West Sussex, UK. Posts: 2,296	Re: AVO 2 Panel - restoration ideas? The AVO 2 panel has the same horseshoe magnet as the AVO 7 and seems to suffer from loss of magnetism. I have tried re-magnetising the magnet and replacing it with a neobium magnet. I reported my adventures here: https://www.vintage-radio.net/forum/...d.php?t=165159 I have also breadboarded a digital meter replacement for the AVO 2 panel using peak detection and sample and hold, this works well on the bench on simulation, I am trying to find the main panel from a 2 panel AVO tester with a duff meter to fit it into. see here: https://www.vintage-radio.net/forum/...7&postcount=14 Peter