Workshop Video circuits Ltd panel

Posted by: @gizmo2022

Im new to all of this testing vaccum tubes/valves and I bought an d vintage v33 tester made by VCL. I'm not sure what all the different valves that can be tested on it are

Short answer... None! It's not a valve tester, I'm sorry to say you've wasted your money. I hope you didn't pay a lot, it's worth no more than £10 - £20, and that's just for the useful case and meter for other projects.

The Video Circuits V33 is not a valve tester, it is a CRT (Cathode Ray Tube) tester/rejuvenator, it's for testing the cathode emissions of television picture tubes, you cannot test ordinary valves. You'll notice one of the selectors has Red, Green and Blue, that's for selecting the three different cathodes on the picture tube. That, perhaps should have rung alarm bells for you. Had you searched Google for the device, it would have returned a few threads here and on UKVRRR, that detailed its use.

It was a probably one of the worst, crude and brutal budget CRT tester/rejuvenators around. Aimed at those that could not afford the better devices, the rejuvenation side had no finesse, it was really kill or cure, a device best confined to the bin of history. I wouldn't let that anywhere near any of my TV CRT's. When put up against the superb B&K 467, Leader 910LCT or Muter, you'd understand why.

The block you mention houses the different types of sockets or CRT's it could test. You would attach the correct socket to the end of various CRTs. The "Mono" refers to "Black & White" CRT's, PIL is an In-line (gun alignment) tube and Trinitron were Sonys CRT, not forgetting delta gun types.

Valve Testers

UK valve testers were produced by:-

AVO, starting with the 2-panel, and then the Various VCMs MK1,2&3 and not forgetting the military CT160. These are very much sought after and as such command extremely high prices, especially the CT160. Also, very complex devices to set and use for a test, you need a data book to dial in all the correct voltages to grid, screen anode etc.

Mullard, produced a number of what were termed high speed valve testers, MKI, MKII, MKIII, they also produced a military version too. These testers were almost fully automatic, achieved by the use of punch cards to set the valve up for testing. The results displayed on a CRT, quite popular and often found in TV radio shops, where the customer could take in their valve, find the appropriate test card, hand over shilling, and test their valve.

Taylor, was another popular tester. Models I believe are 45A, B,C and I think a 47. Like the AVO this also required manual setup.

All the above testers fetch a small fortune these days. You can also get American testers, but you need to be very wary about what you get, what can be tested and of course paying attention to the 110V requirements.

Devil's Advocate

Ask yourself why you want one......

Unless you're building an amp, to match valve pairs, a dealer having to provide matched pairs, needing to provide accurate mutual conductance readings to customers buying valves from you, a valve tester is a very expensive luxury toy. The average hobby repairer does not need one, they already have the best valve tester they could possibly have, the device the valve came from and its circuit data. Also, the reality being valves are least likely to be the cause of a radios or TVs problems, they are the most reliable component in the circuit, if in doubt a quick proof is substitution.

Those of us who were never in the trade, all go through the same phase of wanting a valve tester, an itch that required scratching. Equally, those of us fortunate to have bought one, myself included, find we use it infrequently, an expensive toy gathering dust. So the lesson is, you need to be really asking yourself why you want one, and is the argument strong enough to shell out a very large amount of money to purchase one.

If after that you decide you do still want one, then perhaps a little more research next time. A harsh lesson learned, but a valuable one, as I doubt you'll repeat the same mistake again.

@gizmo2022 

Many faulty valves can be diagnosed by using the voltage and current tables given in the service manual for the set you are working on. Valve characteristic books can also help, having a small stock of known good valves on equipment you are repairing is always useful.

I was in the trade about 20 years and didn’t have a valve tester and managed quite well.

There are cases has noted by Chris were a valve tester is useful and if your requirements fit those situations then yes it’s would be worth while but for day to day bread and butter work they are not a necessity.

What equipment are you interested in repairing?

... they were OK for testing a CRT, but awful at rejuvenating! A place where I worked referred to it as "Phil's cathode stripper"

I'll quote John Wakely on his experience with it.

Posted https://www.vintage-radio.net/forum/showpost.php?p=710596&postcount=2

 

Its naughty to describe as "VIDEO CIRCUITS VALVE / TUBE TESTER" as listed

I was given one of these years ago, I thought I’d try it out on an old VGA monitor I had lying about, I’m sure I didn’t select rejuvenate, but it made some sparks in the tube neck, and the tube then no longer displayed red! Don’t know what happened to it, I hope it’s not in my lock up, can’t stand the thought of having to pay to keep such a piece of junk!!

Regards,

 Lloyd