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Tuning calibrating of my valve tester?

4/30/2006 9:18 AM
Satamax Tuning calibrating of my valve tester?
Hi everybody!  
Well, i've bought a valve tester  
I would like to understand more about it. How do i calibrate it? What test thoses ľA relate to? Isolation, or emission? Both? Could i improve it, to calculate the transconductance and other parameters, beside isolation and emission?  
Thanks and best regards.  
4/30/2006 11:33 AM
Hi Max,  
Never seen that type of tester before, at a guess I would say it's an emission tester. I'm sure there's others on this forum who will pipe in soon with advice. If it's fairly old, I usually update the caps, check all resistors for drift, burn marks ect, clean all switches and sockets before putting it into service. See if you can download a schematic for it and check all voltages ect.  
4/30/2006 2:28 PM
Thanks a lot Jack!  
Well, it's an emission and shorts tester. There's very few components in there :D About one diode, one or two resistors, the switches, and the multitap transformer :D I'll take a picture of the internals later.  
4/30/2006 7:28 PM
John Culp

If it's an emission and shorts tester, you can't test transconductance. You need a transconductance tester for that.
4/30/2006 9:12 PM
Thanks a lot John!  
Well, what brand of tested could i get cheap enough? I paid this one about 120 zoros, i'm keen on an AVO or a B&K , but realy i don't have the dough for one :D Therefor i thought i could may be modify or add components onto this one to be able to test and match valves.  
4/30/2006 11:44 PM
John Culp

I just bought off of eBay for $90 plus shipping an EICO 666. It doesn't exactly measure transconductance, but that's pretty much what its "dynamic conductance" testing actually is.  
There's a good section on various tube testers to be found at:
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