Have been searching for a good book on repair and servicing of tube testers, thanks

The more complicated tube testers may have a bit more to them, but most tube testers and certainly the emissions testers have only basic components (resistors, condensers (if any), switches, transformer, and a meter). All you really need to do is be sure that all resistors are exactly on value. Replace condensers if there are any. If the switches malfunction, repair or replace them. My selector switch arced over on my Eico 625, so I replaced it with a porcelain one I obtained from some junked military surplus equipment. The resistors were drifted, too, so I replaced them. This particular model uses a 6H6 tube for rectification of alternating current to the meter when making a line test (setting the tester for exact 115 volts line voltage for accuracy and consistency). The meter does not draw much, so unless the tube is really weak, it is not likely to affect the reading. Check with a spare and see if you notice a difference. On more modern tube testers, you will find solid state diodes. The only thing to check with these is whether they are open or not and whether they leak or not (current flows backwards, which it shouldn't). As for the meter itself, you simply want to check to see that it moves smoothly and does not hang up or anything. There are ways to adjust the bearings, but the hair springs are very tricky and should be left to a watch/clock repairman. Tube sockets are readily available and easily replaced (on most testers...some testers have custom sockets). Sometimes you can tighten the contacts on tube sockets.

T.D.

:The more complicated tube testers may have a bit more to them, but most tube testers and certainly the emissions testers have only basic components (resistors, condensers (if any), switches, transformer, and a meter). All you really need to do is be sure that all resistors are exactly on value. Replace condensers if there are any. If the switches malfunction, repair or replace them. My selector switch arced over on my Eico 625, so I replaced it with a porcelain one I obtained from some junked military surplus equipment. The resistors were drifted, too, so I replaced them. This particular model uses a 6H6 tube for rectification of alternating current to the meter when making a line test (setting the tester for exact 115 volts line voltage for accuracy and consistency). The meter does not draw much, so unless the tube is really weak, it is not likely to affect the reading. Check with a spare and see if you notice a difference. On more modern tube testers, you will find solid state diodes. The only thing to check with these is whether they are open or not and whether they leak or not (current flows backwards, which it shouldn't). As for the meter itself, you simply want to check to see that it moves smoothly and does not hang up or anything. There are ways to adjust the bearings, but the hair springs are very tricky and should be left to a watch/clock repairman. Tube sockets are readily available and easily replaced (on most testers...some testers have custom sockets). Sometimes you can tighten the contacts on tube sockets.
:
:T.D.

I was looking for something that would have some calibration instructions and troubleshooting procedures and some good explanations of how they operate.

Other than factory service manuals I doubt that anything has been published on repair and restoration of tube testers specifically.

If you are looking at the simple ones, like Simpsons, Jackson, Eico, the tall store models, etc those are all emmision types, and operate fundamentally the same way. As long as the heater voltages measure at or just below the indicated voltage, and that calibration can be achieved in the manner described in the instructions for each model, there is not much else to adjust. If a component goes out of value, it is rather easy to locate.

When you get to the high end testers like the TV-7, the technical manual that most should have, go through callibration procedures and trouble shooting.

Even though some of this repeats what Thomas listed, I agree with him that there isn't that much else that can go wrong with those units, after having repaired a number of those units myself.

Sometimes, it is good to establish a baseline for a set of specific tubes. two testers that I have I have calibrated against a few "standards tubes" (tubes tested on a TV-7 that was fully calibrated) that test low on one tester and high on the other for tubes 45 and 2A3, but give predictable results that allow an accurate determination of merit.

In the end, many tubes will test low on an emission type tester, even down around 25% to 30% and stil perform very well in some radios. While most that measure above 35% can still function well in most radios.

::The more complicated tube testers may have a bit more to them, but most tube testers and certainly the emissions testers have only basic components (resistors, condensers (if any), switches, transformer, and a meter). All you really need to do is be sure that all resistors are exactly on value. Replace condensers if there are any. If the switches malfunction, repair or replace them. My selector switch arced over on my Eico 625, so I replaced it with a porcelain one I obtained from some junked military surplus equipment. The resistors were drifted, too, so I replaced them. This particular model uses a 6H6 tube for rectification of alternating current to the meter when making a line test (setting the tester for exact 115 volts line voltage for accuracy and consistency). The meter does not draw much, so unless the tube is really weak, it is not likely to affect the reading. Check with a spare and see if you notice a difference. On more modern tube testers, you will find solid state diodes. The only thing to check with these is whether they are open or not and whether they leak or not (current flows backwards, which it shouldn't). As for the meter itself, you simply want to check to see that it moves smoothly and does not hang up or anything. There are ways to adjust the bearings, but the hair springs are very tricky and should be left to a watch/clock repairman. Tube sockets are readily available and easily replaced (on most testers...some testers have custom sockets). Sometimes you can tighten the contacts on tube sockets.
::
::T.D.
:
:I was looking for something that would have some calibration instructions and troubleshooting procedures and some good explanations of how they operate.

Well, I bought the book by A Douglas. What a joke, lots of fluff, good reading for a novice but it was a waste of money, very biased and not written by a person with much repair experience in the tester field, still looking for something worth reading.

There are articles on the internet. Still, a book is nicer to have.

T.

Hi 7mmMag,
I'm not a novice tho not a whip like some folks on this forum. I've had extensive training in Radio repair...long time ago. I have way too many tube testers and not enough sense to explain why. I don't knock people who may imply it takes some doing to repair and "calibrate" tube testers. I just don't believe that. One with skills, training and/or experience above a novice should be able to tackle and accomplish the repair and calibration of tube testers. More so with all the help on the internet. I somewhat flew by the seat of my pants prior to internet and did ok with what manuals and knowledge I had. But the thing I gained with the internet was all that "corporate" knowledge, tips, tricks and free manuals in some cases. Between the time shops tossed their testers, yes a lot did, and this monstrous knowledge base it was a dry lake, at least for me. Now if I get another tester, I'm almost assured to be able and get a manual and help. There's the ongoing discussion about what's the best tester and I'm not going there. But most all agree on the information about repair of testers. I would say regardless of the tester we all just want to know if the bad is bad and the good is good. What has been said by others is it...there just ain't no more I'm aware of. If there was a book you would have to have a lot of filler, perhaps fluff, to even make a book. A pamplet is more like it. On what model tube tester do you need information? I believe with your skills you can understand what to do with information folks would provide. And if you can come up with information for a book and feel there's a market for it, I can get it printed. By-the-way, the thing I can't do is recover some of these tube testers; likewise amps and I just can't refinish wooden cabinets. But there's lot of information on how to do it. So my rating on that is below novice. Strangely, it doesn't bother me. Old age I guess.

Well, I bought the book by A Douglas. What a joke, lots of fluff, good reading for a novice but it was a waste of money, very biased and not written by a person with much repair experience in the tester field, still looking for something worth reading.

Hi,
Perhaps the best way to address the tube testers is the way Bill did.

Perhaps the only really good treatment and description of the types of testers is found in an RCA tube manual in the section where they discuss "testing". They discuss the advantages of each type/method of testing.

To be sure, the final judge of merit of a tube is the circuit you put the tube into. However, if you plan on marketing tubes in a really big way, perhaps the best tester to get is a TV-7 (most vendors who sell "matched" tube pairs use these because they address more of the variables of tube performance, and as for why, RCA goes into that. The other types of testers that are out there, most have just a few components, and relying on your knowledge of electronics theory, that alone should be enough to make any tester servicable and reasonably accurate.

Otherwise, as I mentioned before, no one has written the type of book you are looking for.

:Hi 7mmMag,
:I'm not a novice tho not a whip like some folks on this forum. I've had extensive training in Radio repair...long time ago. I have way too many tube testers and not enough sense to explain why. I don't knock people who may imply it takes some doing to repair and "calibrate" tube testers. I just don't believe that. One with skills, training and/or experience above a novice should be able to tackle and accomplish the repair and calibration of tube testers. More so with all the help on the internet. I somewhat flew by the seat of my pants prior to internet and did ok with what manuals and knowledge I had. But the thing I gained with the internet was all that "corporate" knowledge, tips, tricks and free manuals in some cases. Between the time shops tossed their testers, yes a lot did, and this monstrous knowledge base it was a dry lake, at least for me. Now if I get another tester, I'm almost assured to be able and get a manual and help. There's the ongoing discussion about what's the best tester and I'm not going there. But most all agree on the information about repair of testers. I would say regardless of the tester we all just want to know if the bad is bad and the good is good. What has been said by others is it...there just ain't no more I'm aware of. If there was a book you would have to have a lot of filler, perhaps fluff, to even make a book. A pamplet is more like it. On what model tube tester do you need information? I believe with your skills you can understand what to do with information folks would provide. And if you can come up with information for a book and feel there's a market for it, I can get it printed. By-the-way, the thing I can't do is recover some of these tube testers; likewise amps and I just can't refinish wooden cabinets. But there's lot of information on how to do it. So my rating on that is below novice. Strangely, it doesn't bother me. Old age I guess.
:
:
:Well, I bought the book by A Douglas. What a joke, lots of fluff, good reading for a novice but it was a waste of money, very biased and not written by a person with much repair experience in the tester field, still looking for something worth reading.