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 Valve Testers
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 Return to top of page · Post #: 1 · Written at 4:36:37 PM on 13 July 2019.
Arty41's Gravatar
 Location: Brisbane, QLD
 Member since 18 September 2010
 Member #: 118
 Postcount: 289

Could anyone recommend a reasonably priced valve tester? I can't afford an AVO or Hickok even though these would be the pick. I want to sell my excess stock of valves and be able to say they tested OK. I have the opportunity to buy a Lafayette 99-5012 which will only check emission, would it be good enough ?


 
 Return to top of page · Post #: 2 · Written at 8:33:58 PM on 14 July 2019.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

The saying goes: The best tester for a valve is the circuit it's designed for.

The very least you need is a shorts tester. Plain emission testers can mask a number of valve problems while showing "good" emission. Personally, if I buy a "tested" valve, I expect it to have been tested on an AVO or equivalent and by a competent operator. Even then I factor in the potential for errors. NOS is one thing, used is another.

(I use a B&K 747B -- their first transistorised tube tester. Very easy to use but it's not suitable for antique equipment).


 
 Return to top of page · Post #: 3 · Written at 6:53:49 AM on 15 July 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 574

I don't bother with a valve tester, there are so many parameters to test to ensure correct working in a circuit.
However, when you have a bunch of valves to sort out a simple emission test would at least give a "goodness" indication and sort out the very basics. Does it have a vacuum, is the heater intact, does the cathode have any emitting material left?
The next step would be shorts between electrodes and after that a bunch of dynamic tests to do with the gain of the valve and i'll bet nobody carries that out.
When you look at most testers they have coloured sections on the dial related to emission, "poor/fair/good" and a bunch of set ups to set a valve by. All that's going to do is check emission by comparison , not very scientific but useful in a workshop where you are dealing with typical valves all the time and just want to know if the valve is "tired" or shorted.

For your use I would just go for a tester that does emission and shorts, that will at least check if the valve will light up, stay lit up and conduct current.

Fred.


 
 Return to top of page · Post #: 4 · Written at 5:45:31 PM on 15 July 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3706

Radio Club has just had four members die in two months, so there will be a bit of equipment about. One had a Paton VCT, it probably works still, as I repaired it a few years ago.


The only real way to test them is in a circuit. And I did see a setup for exclusively testing OP tubes used in professional amps.

Marc


 
 Return to top of page · Post #: 5 · Written at 3:57:48 PM on 5 August 2019.
Jhndragoon's Gravatar
 Location: Sydney, NSW
 Member since 26 July 2019
 Member #: 2369
 Postcount: 13

A good general purpose vt is the paton et4a or heathkit tc1 they sell on ebay for $100 - $200 and have a good selection of sockets
I would not recomend a calston 223 due to lack of suitable sockets and a lot of leaky rf (not good if you have a pacemaker!) a jittery photo available on request


 
 Return to top of page · Post #: 6 · Written at 5:52:24 PM on 5 August 2019.
Arty41's Gravatar
 Location: Brisbane, QLD
 Member since 18 September 2010
 Member #: 118
 Postcount: 289

I'm restoring a Paton VCT-2 at the moment, see how it turns out.


 
 Return to top of page · Post #: 7 · Written at 10:14:53 AM on 6 August 2019.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 196

Whenever I look on fleabay for valve testers they want the earth for them.
If I saw one for $100 I'd jump on it.


 
 Return to top of page · Post #: 8 · Written at 9:39:58 PM on 18 August 2019.
Jhndragoon's Gravatar
 Location: Sydney, NSW
 Member since 26 July 2019
 Member #: 2369
 Postcount: 13

 
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