AVO MK.4 valve tester, range of valves covered

[high_vacuum_house]

Good afternoon,
I am thinking of getting possibly something like a AVO MK.4 valve tester. What range of valves would such a machine cover. I have lots of radio and television valves, quite a lot of them are second hand pulls from boxes under the tables from radio rally's and all are therefore unknown quantities.

I am not really interested in silly audiophile valve work!! but certainly domestic radio and television types as well as valve based test equipment. I presume it would do all E,P,C and U series valves. Would it do things like television EHT rectifiers?

I am also interested in pre-war receivers. Would this test the majority of 1930's receiver valves.

Is there a list of the various valve holder types that are mounted on the top plate?

Many thanks,
Christopher Capener

[ms660]

Valve holders fitted can be found in here:

https://frank.pocnet.net/instruments..._Mk-IVuser.pdf

And here:

https://frank.pocnet.net/instruments...-IVservice.pdf

Valve types and settings can be found here:

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

And here.

https://frank.pocnet.net/instruments...AVO_VDM_23.pdf

Info for Avo valve testers in general can be found here:

https://frank.pocnet.net/instruments/AVO/index.html

Lawrence.

[high_vacuum_house]

Many thanks for the above links, This is a huge amount of very useful information. I think I will find all of the answers to questions regarding valve testers here. This will give me plenty of hours of reading!!

Regards,
Christopher Capener

[Radio Wrangler]

If you want an AVO MKIV, then you'll probably have to pay a silly audiophile price for it because their bids are setting the level of the market.

You could use a late model Taylor and make adaptors if needed.

David

[Boater Sam]

I was faced with the same desire but found the ridiculous prices demanded for Avo testers to be outside my pocket.
Then I questioned what I needed a tester for. I didn't need to know exactly the gm of a valve, only that it was working reasonably well, at least good enough to be usable.
Faced with 1000s of valves to test I built a very simple tester using a EL81 as series current control and cheap digital meters from China for volts and current readings. Heater volts are regulated by a buck/boost module.
Towers valve index, National Valve Museum, etc. provide all the parameters for most valves, setting anode and grid volts quickly give a go/no go on emission and finds any shorts.
I have B7G, B9A, B8A, B8G, B9G, Octal and M-Octal holders with an octal plug in loom with croc clips for anything else like B4, B5, B7, B9.
In the final analysis, whether the valve works in a set or not is the best tester available.
EHT and mains rectifiers can be tested but not up to the maximum ratings obviously.

[mole42uk]

I would happily recommend our own “Sussex” if you’re thinking of building your own.
It’s reliable, not expensive and well supported by several members on here.

[radiotechnician]

This is my Avo valve tester. It came from where I worked.

And when I retired, the firm gave me the B & K 747, the tester that
replaced it.

They also gave me cartons of all their tubes. Which hadn't be used
in years.

A good riddance handshake ?

[dave walsh]

My life long friend has lived in Kitchener Ontario since 1968 and worked in Industrial Electronics on the shop floor. It's Canada, so knowing what the people are like, I'd assume that the two gratis Valve Testers were purely a gesture of appreciation

Dave W
Bexhill

[Bazz4CQJ]

Originally Posted by mole42uk

I would happily recommend our own “Sussex” if you’re thinking of building your own.
It’s reliable, not expensive and well supported by several members on here.

While greatly respecting the 'Sussex', there was a thread on here some time ago where someone showed the tester they had assembled using a module which I think came from a French company, and connecting this to a PC, the software drew a wonderful set of curves in the blink of an eye. It did leave a good impression!

B