Valve tester

[bumpy]

I am looking to buy a valve tester. Can anyone give me any tips as to what to look out for?

[Audio Al]

A valve tester :)

[Arkless Electronics]

I don't have one and don't want one personally. They are a waste of space and usually give highly dubious readings.

[Spectral Morn]

Look for a television repair mans tester kit. Does most valves bar some of the newish Russian ones.

Such as here http://theartofsound.net/forum/showthread.php?2007-Sencore-mighty-mite-mk-7-tube-tester

That is an American one, so step down needed for the mains but it works well despite Jez's comment above and has identified bad valves.

[struth]

Most nowadays are not of much use tbh . Most just test emissions and arent overly accurate, especially with modern valves. I had use of a avo in workshop... It was huge and needed a 2 week course to learn how to switch it on :eyebrows: mullard made a small one that was what we usually used. We made out own crt testers and boosters, as tge ones you bought were a bit vicious and more likely to strip the tube.
If you get one, first thing to do is retension all the valve bases as they are usually loose and give wrong indications.

[topoxforddoc]

Chris,

What sort of valves are you looking to test - small signal valves e.g. double triode ECC 83 etc or large power valves e.g. KT66, 300B? Do you want to just check that they are ok, or are you planning to use it to match up valves? I have an AVO MkIV, but they don't come cheap nowadays. Also the meters are fragile and replacements are unobtanium.

Here's an AVO Mk2 on the *Bay - if it works fine (so says the seller), then that's a reasonable price
http://www.ebay.co.uk/itm/AVO-VALVE-TESTER-VCM-Mark-2-/112116512438?hash=item1a1aaa36b6:g:f8kAAOSwd2xXQZ4 Y

Don't bother looking at the original two panel AVO

Charlie

[Radford Revival]

Going against the grain I would say that if you're doing a lot of work with valves, a decent tester such as a VCM163 can be exceptionally useful - especially seeing as you can shove in pretty much any valve and get a ballpark figure for performance. Obviously the final arbiter is how well the valve works in its intended circuit, but if you just want to plug in an oddball valve and test for current / gain against the book value or at your chosen operating point, it's fantastic. No need to build a test jig for a specific valve.

[struth]

Going against the grain I would say that if you're doing a lot of work with valves, a decent tester such as a VCM163 can be exceptionally useful - especially seeing as you can shove in pretty much any valve and get a ballpark figure for performance. Obviously the final arbiter is how well the valve works in its intended circuit, but if you just want to plug in an oddball valve and test for current / gain against the book value or at your chosen operating point, it's fantastic. No need to build a test jig for a specific valve.



Sure, agreed. If your going to use it a lot especially with older nos valves, then fine, but get a good one... Costs a few bob but will help. For most of us it is not really good value.

[anthonyTD]

Totaly agree, I use VCM 163's myself, and have had most of the earlier AVO's too, If your repairing valve equipment all day [like i am] you need a decent valve tester!
Going against the grain I would say that if you're doing a lot of work with valves, a decent tester such as a VCM163 can be exceptionally useful - especially seeing as you can shove in pretty much any valve and get a ballpark figure for performance. Obviously the final arbiter is how well the valve works in its intended circuit, but if you just want to plug in an oddball valve and test for current / gain against the book value or at your chosen operating point, it's fantastic. No need to build a test jig for a specific valve.

[Barry]

Chris,

What sort of valves are you looking to test - small signal valves e.g. double triode ECC 83 etc or large power valves e.g. KT66, 300B? Do you want to just check that they are ok, or are you planning to use it to match up valves? I have an AVO MkIV, but they don't come cheap nowadays. Also the meters are fragile and replacements are unobtanium.

Here's an AVO Mk2 on the *Bay - if it works fine (so says the seller), then that's a reasonable price
http://www.ebay.co.uk/itm/AVO-VALVE-TESTER-VCM-Mark-2-/112116512438?hash=item1a1aaa36b6:g:f8kAAOSwd2xXQZ4 Y

Don't bother looking at the original two panel AVO

Charlie

Yes, that's the version we had where I worked (the GEC-Marconi Research Centre). £450 is a resonable asking price for this piece of kit, though I would have liked to see the user operating manual included.

Agreed, don't bother with the 'two panel' AVO. It used a set of plug-in boards, or cards (rather like the Hoover 'Keymatic'), to set up the connections to the appropriate valve base for a given valve type. Useful in their day, but now insufficiently versatile, and any item put up for sale is unlikely to come with the full compliment of cards.

Ag

[topoxforddoc]

Yes, that's the version we had where I worked (the GEC-Marconi Research Centre). £450 is a resonable asking price for this piece of kit, though I would have liked to see the user operating manual included.



The AVO VCM manuals are freely available in the inter web! Here's one for the AVO VCM Mark 2 in the E*ay advert I linked

https://frank.pocnet.net/instruments/AVO/HR/ValveTesters/manuals/VCM_Mk-II.pdf