Tube tester for 6922 family & 6CG7/6FQ7 tubes

Dave D said:
It seems with that question I killed my own thread.
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My feeling is that Hickok is a safe investment. You will pay a premium for it but, you get it all back with interest down the road if you sell. I have a Hickok 539 variant (WE KS-15560) and it is a beast. It is great in that it covers everything but so big I need a dedicated space for it. You clear the bench when you drag it out and do nothing else.

That said, there are many other excellent testers out there as suggested. For regular bench use, you really only need one that covers dual 9P triodes, power tetrodes & pentodes, common octal signal tubes, & rectifiers and maybe novals like the 7868. At least, that is what I usually end up testing. If you find a Hickok at a price you can handle, jump on it. If not, go with one of the "lesser" brands, in a heartbeat.
 
This thread is a few years old, but FWIW the manual for the 666/667 tells you exactly how to develop settings for unlisted tubes. If the thing has a socket to fit, or if you can make an adapter, you can test it. Feel free to PM me if anybody wants more info.
 
My Hickok 6000A tests them, but I don't know that I trust its readings. The 6DJ8 family behaves strangely in my tester. On all other tubes I've tested, the meter needle reaches a steady state value very quickly; a second or less I'd say. On the 6DJ8 the needle continues to creep higher and higher for a long time, perhaps 10 seconds or more (it's been a while since I tested one). I don't know if the initial reading or the final reading is right, or if either of them is right. I'm guessing the change in reading over that time could be 25% or so.
 
I wonder if that says more about the tube being on its way out, rather than the tester. I recently ran across a couple 12AX7s that were very slow to "wake up" and also had low gain. Same sort of behavior. They also tested very poorly at low current levels, but were better at the normal test currents. Ah, for want of one of those old Tektronix tube curve tracers, the predecessor to the 575 transistor curve tracer.
 
JonL said:
My Hickok 6000A tests them, but I don't know that I trust its readings. The 6DJ8 family behaves strangely in my tester. On all other tubes I've tested, the meter needle reaches a steady state value very quickly; a second or less I'd say. On the 6DJ8 the needle continues to creep higher and higher for a long time, perhaps 10 seconds or more (it's been a while since I tested one). I don't know if the initial reading or the final reading is right, or if either of them is right. I'm guessing the change in reading over that time could be 25% or so.
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Yep, check around AK as many Hickoks DON'T do these high transconductance tubes well at all. I test my 6DJ8s on a simple emission Knight 600 as my Hickok 600A gives low, erratic, untrustworthy readings on this tube family.
 
I don't think it's a worn tube issue. I've tested a couple dozen 6DJ8s of various makes from various places and I think they've all done this.
 
Andyman said:
Yep, check around AK as many Hickoks DON'T do these high transconductance tubes well at all. I test my 6DJ8s on a simple emission Knight 600 as my Hickok 600A gives low, erratic, untrustworthy readings on this tube family.
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Correct. I have an old Navy TV-3BU tester. Actually a better tester than the more common TV-7 that everyone seems to use to test and sell tubes on the auction site. The 6DJ8 is a high transconductance tube and it causes oscillations within the Hickok style testers. That is what gives the erratic and quite often higher readings. Hickok tried to fix this problem by adding small ferrite beads on the leads inside the tester near the tube sockets. I have experimented with this by making an external adapter with ferrite beads on the leads. I have had some success but I still can't accurately test my 6Dj8s.

Buyer beware on the auction site when you see 6DJ8s listed with greater than 100% transconductance readings!

Steve
 
Old thread, but I thought I'd add this for those looking for this info

I have a Hickok 539a tester and the 6922 settings that sleddogman posted for the 6000a seems to work for the 539a also *except for the bias voltage*

Selectors - EV-7608-0 for triode 1, EV-2103-0 for triode 2
Filament - 6.3v
Bias - 4.6 v <------------------
Shunt - 89
Function - A
Minimum Mut. Cond. - 5500 < --- my *new* tube tested @13700

I determined this based upon a new tube I got from Upscale Audio which had their test results written on the box.

With the bias voltage set to 4.6 volts I got the same result Upscale did. My tester has not been calibrated for many years so this may be way off, but I was able to tell which tubes were effectively killed by my Audible Illusions Modulus 3.

If anybody has a better way of determining if this is a valid way of doing this I'm all ears.
 
I've encountered the exact same problem.
This is an old thread, but I don't see any easy solution yet.
I have a Knight 600 tube tester which tests short/emission/gas, and its chart does not show for 6922 family tubes.
Anybody know which setting I can use to test them?
Thanks.
 
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