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Need help with understandin average mutal conductance

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chaztaylor

New Member
I recently bought out 3 radio store full of vacuum tubes. I have roughly 100000 vacuum tubes to test on a hicok tube tester that I just bought. I understand the roll chart up until it say average mutual conductance. Is that the min the tube should test to be good. Does that number for example 5000. If I test the tube and it tests at 5100 is that a really strong tube or just barely good. Thanks for any help.
 
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I bought a stash of 6000 a couple of years ago and just organizing that many took weeks. I had zero knowledge of tubes, I did not know the difference between a 12ax7 or a 2a3.
One of the hickok guys will be around soon to answer your question and welcome to AK.
 
Life is too short to test all of them. 99% of tubes are worthless and no longer used. You want to figure out what the 1% is. You just want to test the ones that are used in ham, audio and guitar for the most part. There are a billion tubes for sale on eBay right now and a very short list of what is actually selling or sell-able. Good luck. Robert
 
I am married . No she doesnt like it . And I am just separating tubes to go to go in the trash and tubes that are worth testing. It will take me about a week to finish up this little bit. And it will be cleaned up
 
Take the tubes that aren't worth testing and put them up for free on Craigslist or something. Someone might come take them off your hands. Different things are worthwhile to different people, though frankly most of the non-audio tubes have virtually zero cash value. Things can be built around most of them though, and someone might wish to experiment. Might save some landfill space if nothing else.
 
Im not sure what im going to do with them yet. But yes I would say so far about 65 percent are worth a dollar similar to selling books on Amazon
 
I have pretty much every kind of tube there is so you would be suprised some are worth a lot becuse there is like no of them for example I have a pj7 ge tube I have never heared of or seen one of these ever and I have been selling tubes for 5 years on a lot smaller scale
 
Thats not a bad Idea I will need help from people on here from time to time.with this many tubes I can for see me needing answers to questions. So its only fair that I give back to the community. Im not real good with electronics so I cant help people with there questions unfortunately. But I can help this way. I will check it out.
Thanks
 
IMO, testing tubes is time intensive. You have to wait for them to warm up, then often test multiple sections, which means flipping levers or dials. There's a tester that's set up with punch cards- if I had boatloads of tubes to test I'd want something like that, or a computerized setup. I'd only sort out the expensive audio outputs and small signal stuff to test. The rest, sell as-is or donate.
 
gadget73 said:
Take the tubes that aren't worth testing and put them up for free on Craigslist or something. Someone might come take them off your hands. Different things are worthwhile to different people, though frankly most of the non-audio tubes have virtually zero cash value. Things can be built around most of them though, and someone might wish to experiment. Might save some landfill space if nothing else.
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Most but not all. Don't forget the radio-collectors community, and many "TV" tubes have been or can be recycled for audio use. Just look at the current value of a N.O.S 1L6, 42 , 45 , or 6LF6 ( a typical TV tube). N.O.S Tuning indicator (aka "magic eye") tubes are getting scarce and highly in demand. Even some small Compactrons (6C10,...) were used in audio and guitar amps and are quite expensive now. 4- digit industrial , "5-stars" or "Special Quality" tubes (5751,5963,6922...) also desserves your attention, being used as high grade audio tubes. These are only a few exemples and I would not trash them before a careful evaluation, there might be some "non-audio" treasures hidden in your lot, but if you're not an expert you'll probably miss a few of them. The "99% worthless" quote seems very pessimistic, IMO
 
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