AVO valve tester question. - UK Vintage Radio Repair and Restoration Discussion Forum

Bomber county · 28th Jul 2021, 9:34 am

I have recently acquired this rather nice early AVO tester and data books, it works OK. Went through my collection of 6V6's yesterday with no issues however its left me scratching my head a bit with regards to 12AX7's, 12AU7's etc. I have the rotary switches sussed out (641 337 412) but not sure where to set the "Set mA/v" selector and the "screen" selector. Someone has hand written some settings in the data book but left the S.V and MA.v columns blank. Obviously they are double triodes so how do I check one side then the other?

Chrispy57 · 28th Jul 2021, 11:46 am

Hi - do you have an instruction manual? I have a 5Mb PDF of the military instruction manual I could email to you if you like? Basically in paragraph 71 it says "set the anode selector switch to A2 and repeat".

Cheers
Chris

Bomber county · 28th Jul 2021, 12:01 pm

Quote:

Originally Posted by Chrispy57

Hi - do you have an instruction manual? I have a 5Mb PDF of the military instruction manual I could email to you if you like? Basically in paragraph 71 it says "set the anode selector switch to A2 and repeat".

Cheers
Chris

I do have an original instruction manual for it plus a couple of valve data books but they are in very fragile condition so yes a downloadable one would be most handy. I am missing the full set of selector settings for 6AT6, ECC82, ECC83 and E180CC currently. The selector drum settings are fairly straightforward to work out its just the controls on the meter part of it that need clarifying.

Chrispy57 · 28th Jul 2021, 12:22 pm

I have done a quick jpeg of 3 of these 4 equivalents, and tried to attach the PDF which may be too big for this site in which case if you forward an email address I will post it there.
6AT6 = CV452,
ECC82 = CV491,
ECC83 = CV492,
E180CC = not mentioned

Cheers
Chris

ms660 · 28th Jul 2021, 12:27 pm

All in here:

https://frank.pocnet.net/instruments...AVO_VDM_17.pdf

Lawrence.

Simon Gittins · 28th Jul 2021, 12:45 pm

It's worth putting "avo valve tester manual errors" into the Search box at the top before you find errors the hard way.

This search also brings up a very useful AVO Valve Data Manual 23rd edition in OCR PDF format.

Bomber county · 28th Jul 2021, 2:26 pm

Thanks chaps, getting my head round it now I think

Electronpusher0 · 28th Jul 2021, 3:15 pm

Its worth noting that the "2 panel" AVO tester only goes up to a gm reading of 10, this can be problematical with valves such as EL84 which often go above 10.

Peter

28th Jul 2021, 9:34 am	#1
Bomber county Pentode Join Date: Oct 2009 Location: Holbeach, Lincolnshire, UK. Posts: 134	AVO valve tester question. I have recently acquired this rather nice early AVO tester and data books, it works OK. Went through my collection of 6V6's yesterday with no issues however its left me scratching my head a bit with regards to 12AX7's, 12AU7's etc. I have the rotary switches sussed out (641 337 412) but not sure where to set the "Set mA/v" selector and the "screen" selector. Someone has hand written some settings in the data book but left the S.V and MA.v columns blank. Obviously they are double triodes so how do I check one side then the other? Attached Thumbnails

28th Jul 2021, 11:46 am	#2
Chrispy57 Hexode Join Date: Mar 2020 Location: Rochdale, Greater Manchester, UK. Posts: 453	Re: Avo valve tester question Hi - do you have an instruction manual? I have a 5Mb PDF of the military instruction manual I could email to you if you like? Basically in paragraph 71 it says "set the anode selector switch to A2 and repeat". Cheers Chris

28th Jul 2021, 12:22 pm	#4
Chrispy57 Hexode Join Date: Mar 2020 Location: Rochdale, Greater Manchester, UK. Posts: 453	Re: Avo valve tester question I have done a quick jpeg of 3 of these 4 equivalents, and tried to attach the PDF which may be too big for this site in which case if you forward an email address I will post it there. 6AT6 = CV452, ECC82 = CV491, ECC83 = CV492, E180CC = not mentioned Cheers Chris Attached Thumbnails

28th Jul 2021, 12:27 pm	#5
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Avo valve tester question All in here: https://frank.pocnet.net/instruments...AVO_VDM_17.pdf Lawrence.

28th Jul 2021, 12:45 pm	#6
Simon Gittins Heptode Join Date: Jan 2006 Location: Cornwall, UK. Posts: 506	Re: AVO valve tester question. It's worth putting "avo valve tester manual errors" into the Search box at the top before you find errors the hard way. This search also brings up a very useful AVO Valve Data Manual 23rd edition in OCR PDF format.

28th Jul 2021, 2:26 pm	#7
Bomber county Pentode Join Date: Oct 2009 Location: Holbeach, Lincolnshire, UK. Posts: 134	Re: AVO valve tester question. Thanks chaps, getting my head round it now I think

28th Jul 2021, 3:15 pm	#8
Electronpusher0 Nonode Join Date: Jun 2016 Location: Bognor Regis, West Sussex, UK. Posts: 2,300	Re: AVO valve tester question. Its worth noting that the "2 panel" AVO tester only goes up to a gm reading of 10, this can be problematical with valves such as EL84 which often go above 10. Peter