Whats a good tube tester?
 

Anyone know what a good tube tester that would work with most stereo tubes and TV tubes through the 60s.
I'm not looking for anything to test any early or exotic tubes just normal stuff i don't really know where to start...

I have used a B&K dynajet 606 for about 1.5 decades now, and have found it to be fairly reliable. They will do almost all octal and newer types.

Some have mocked it and suggested I buy a some fancy overpriced Hickok mutual conductance model, but I've never seen any advantage to doing so.

If you don't care about testing any of the Pre-Octal types, a B&K 747 is a really nice unit, but getting a bit expensive.

The Eico 667, while not a true transconductance tester, is pretty good, with decent availability of tube settings online.

I have my B&K Dyna-Jet 707 for about 48 years. It's a little beat now, from carrying it in the trunk of my car, when still doing TV repair work. I also have a Tripplett mutual conductance job, that even tests some crazy looking transmitting tubes. Too much work with the setup.
The B&K is not just a simple emissions tester like a Heathkit or Eico. It's considerly better than that. :thmbsp:

I like the B&K Dynajet series tube testers for later era TV and audio tubes. The 606 is what I normally use for that job. And as pointed out, reliable and better than the simple emissions testers so a very useful shop instrument.

Any mutual conductance type, as emission is ... well emission. Check eBay lots of them that "Grandpa used to use this old tester thingy and plugged bulbs in to" (not my words). I would not waste time on a straight emission type, a combo is good though... As far as what ones do what, Google is your friend... I myself have a TV-7A, Not the D, but works well enough and a Sencore 140 that I have added test data myself to.

I have an RCA Card-O-Matic, that is supposed to designed after the Hickok offerings. The bad thing is, is that I only have a limited amount of cards for it.
I know it only checks a limited number of tubes, because it only has an octal, locktal and 7&9 pin miniture sockets. It still would be great to have the rest of the cards for it. :scratch2:

I have always liked Hickok products, but they tend to be expensive. Although I have one here in the classifieds that nobody is hitting on. Probably because it is old enough to not be able to test more modern tubes with a compactron type pin configuration. My 6000
A Hickok will do any of them as it is newer, but not for sale unless a crazy price comes into play.

I recently found a B&K 747 in mint condition. It's my first solid state tester. So far it seems to do the job although it seems to have a million settings for each tube. Probably no more than others, just all lined up in side by side levers. Nice light weight unit and tough case more like a gun case than a piece of test equipment.

I have owned for more than thirty years an AVO Mark IV Transconductance Tester. It has always worked reliably and has been the best tester I have seen to accurately determine if the tube is good. No tester is perfect. But the AVO Mark IV is the closest I have found.

You must remember to differentiate between a simple emission checker and a unit which measures transconductance. Very often you will find adequate emission but the tube will not amplify!

The AVO Mark IV is accurately calibrated to display not only whether the tube is bad but also displays the transconductance which can compare with the manufacturers data.

The AVO Mark IV is British and they were exported to North America. I bought mine for 30 Pounds. I found this on on Ebay for somewhat more:

http://www.ebay.co.uk/itm/AVO-MARK-I...item20f2c163d5

I have a B&K 747B and it seems to do very well.. I think this is one of the best testers seeing how they go anywhere between $250 - $400 on eBay.. I happened to luck out on mine as I found a mint one on eBay that didn't go real high on bids.. I think I paid around $260...

I too like my 747B. It's the only solid state tester I have ever owned. I guess I stole mine for $20 from a guy who didn't think that anyone had or messed with tubes, so it was useless. He was happy to get rid of it. I was happy when I got it home and could verify that it actually worked.

The sockets are so tight I venture to say that it was never used. Not a scratch on it.

Eico 667

I've never seen one that did both the early 4-pin / 5-pin tubes and later stuff like compactrons and nuvistors. I have a Sylvania 220 for the early tubes, and a Sencore TC28 for the later tubes.

I'll second this, although the 666 works just fine with an adapter that adds all the newer sockets the 667 has. (Settings are the same between units.)

I only endorsed the 667, well, because I have one... it's also got a nifty transistor tester you can use to match Hfe for audio amps. I have used it to match small signal complementary pairs of PNP and NPN transistors for complementary symmetry audio amps to good effect.

I also have a TV7 for the old stuff, which was always my go-to tester until I got into fixing colour televisions.

I have no idea the dollar value of either, I paid $70 for the TV-7 in about 1994, and got the 667 for free from a relative who bought it at a garage sale for me.

Yes, I still fight that battle and that is a big factor in the question: what is a good tube tester. It depends on the user and his or her needs. If you have the money to blow you can get something like my Hickok 6000A with the adapter for the old tubes. Unfortunately, I don't have the adapter, so I revert to an old 40s model Sylvania 140 for the old stuff and use the Hickok for newer tubes.

I wish I had one that does it all, but I will end with saying don't get a simple emissions tester if you are serious about what you are doing.

The hickocks are nice, but expensive. mutual conductance is nice, but not essential, if youre mainly trying to find shorts and determine if tubes are tired or still have good life left. The Eico testers are better then the cheap emissions testers, and generally affordable, and will get you by until you can score a deal on a better one. I used a model 667 for years before i found a Hickock 600 in an antique store for 40. And another (model 6000)i got from a coworkers uncles estate. another one I like is the Jackson 658, but they seem uncommon. I found one at a surplus dealer for $10. Other overlooked units are the better heathkits, which are true mutual conductance. An emissions tester wont catch all tube issues, but the money you save could be used for a stock of known good tubes to test by substitution, which is more reliable than any tube tester anyway.

You can add a zero to the value of your TV-7 if it's in very good working condition :)

Wow! Well, I have tested a lot of tubes with it, and it's never done me wrong, but if I had to pay $700 I would probably look at more affordable options. That said I wouldn't sell it either, because then how on earth would I test 2A3s.

I am also a lot more adept at using the TV-7 than the 667, I have had it longer and I find the pointer knobs and its physical layout a lot more appealing and better designed for testing lots of different tubes in a row. The 667 has the edge in heater cathode leakage though and I like its great big meter.

The roll chart in the 667 is a bunch of nonsense, I have a printed copy I use instead of wheeling back and forth.

Oh and another word about EICO, mine was originally a kit and the original builder made some wiring errors. I had to troubleshoot it when I got it because certain aspects didn't work properly (the transistor tester). The TV-7 on the other hand came with a bunch of military calibration stickers on it and built like a tank.

The military testers used to be cheap and plentiful.. Wish i had grabbed one back when they were plentiful!

antique electronic supply used to have them for cheap, if I had known they would go up in value so much... oh well I guess I could say that about many things they used to sell cheap!

Perhaps more appropriate for another entire thread, but a discussion on transconductance and the measure of mhos (yes ohms spelled backwards) would be well worth the read for many. It is often disregarded or misunderstood, but in fact is very important in tube performance evaluation. The formula is G (mhos)= plate current/grid voltage.

It breaks down to the ease of electrons to move within a tube and I would call that pretty darned noteworthy. So for this thread about testers I would certainly grab a unit with that capability if I could. Any thoughts?

The same time the unit of frequency CPS became Hz, MHOs became Siemens......I happen to like the old names better.

Always preferred the UK method of noting transconductance, mA/V. Milliamps of plate current change per volt of shift in grid potential. Much more intuitive...

Some old testers (1930s) tested tubes that way. A small battery was used to apply a steady voltage to the grid, then you would compare plate current on the meter as the battery was switched on and off. It was called the 'grid shift' method. Basically it gave you two points on The operating curve. A tube with a worn out cathode would produce less shift in current, and ones with grid issues such as shorts would also not show a normal grid shift.

I like my Hickok 6000A tester. It will test all the common tubes, as well as diodes and transistors. It will test dynamic mutual conductance, shorts, gas, continuity... The whole bit.

I was lucky and got mine for free. I was working in the engineering department back in college and they needed help emptying out the chemistry building stockroom in preparation for remodeling. As we were hauling items out to the big dumpster, I saw a small red suitcase-like box with an electrical tag on it sitting next to it. I opened it up and it was a tube tester! I asked if it was to be thrown away, and was told it was- if I wanted it I could have it. :D After replacing a few paper capacitors and locating owner's manuals, it has served me well.

They can be found in unlikely places... Found my Hickock 600 in an antique store for $40, case was a bit beat up, it was next to a cheap emissions tester that looked nicer but was priced at $125... I have a 6000a, bought from a co-worker who was cleaning out an estate. he asked me about it since he heard i was into tube stuff. I offered him $50 untested and we were both happy with the deal.

I bought my Hickok 580 (their first all solid state tester on par with the 539) 2nd owner at a ham fest in 1987 for $50; it was and still is in mint physical condition. It now needs some minor repairs like the early generation silicon diodes falling apart and a re-cap. Talk about a return on investment 25 years later; they are going for $500-$1,500 on that "auction" site now, top dollar being in the Asian countries. I should probably think about selling it since I'm not really into (or have the itch for) tube stuff anymore.


Tom (PK)

I have several "better" testers, but my go-to for shorts & emission is an Accurate 257. Easy to use, tests most tubes and even some older CRTs and won't break the bank to purchase.

I have one of those too, and my sentiments agree with yours on being quick and easy to just do a go or no-go check on a tube.