What's a good Tube Tester to purchase?

[Magnavox300]

Well, after working on three sets now,
I think it's time I got a tube tester.
I have read that tubes rarely go bad, but I was wondering if they get worn?
Do new tubes work better? Or when they go bad, are they simply done-
Anyone know of a good brand tester I should be looking for?
I have seen many on Ebay, but don't have a clue as to what I should get?
I don't need top of the line, just something that will work well.

Magnavox300

[Big Dave]

EICO 666 or 667. If you get the 666, also get the compactron adapter that was available.

[bob91343]

For at least 99% of the tube testing you are likely to do, almost any emission tester will do. Just make sure it's new enough to handle the tubes you are likely to encounter.

I use an old Precision. I also have the compactron adapter and never use it. It also tests batteries and pilot lamps; I don't use it for that either. I have the original roll chart and a supplement book. I have added some entries for tubes that are in neither of these references.

Basically, you check for enough emission and for shorts. There are, of course, more sophisticated tests but generally they aren't necessary.

[Zenith26kc20]

For TV tubes I like the B&K testers. The shorts and leakage tests are very useful as the sets are not too critical on most tubes. I find IF and tuner tubes are prone to shorts and these testers are sensitive in these areas. If memory serves me right, I use a 607 (it's at home right now and I'm at work so I may have that number wrong.....

[DavGoodlin]

Got three testers since I work on 1920's radios as well as early 1970's TV

My favorite one is the Weston model 798, which tests 30s-50s tubes, but stops short of 9 pin Novars (6DW4-6JE6) or 12- pin compactrons (6JS6-6BW3).

[Electronic M]

I favor a B&K Dyna-Jet 606 for octal and newer tubes and have a heathkit(can't remember the model) for the pre-octal types.

[Tubejunke]

I think that Hickok made the best quality test equipment from the 40s to the 60s. I have found that if you are dealing with early radio and TV and your interests span into the 1960s or 70s, then you will need more than one tester to accommodate the design changes that went on through the years. My favorite is an early 50s Sylvania Electric (unknown model), but it will not test TV tubes from the 60s like compactrons. I have to break out the most practical tester that I have ever found for that which is an Accurate Instrument Model 257, which handles anything that the older one will not as well as crt testing including the large adapters for early color sets.

One nice thing about the Hickoks that I have is that they measure the dynamic mutual conductance of tubes which seems to be a little mentioned factor in tube testing as of late, but according to older electronics publications is nearly as important a factor as shorts and emission tests. For the record I have a Hickok Model 6000A in near mint condition that I may part with. It has the capability of testing the later tube styles. Supposedly those are pretty pricey these days. For a beginner, someone on a budget, or someone dealing primarily with older radio tubes, I have a 1947 Hickok that is in a bit rougher cosmetic condition, but seems to work ok. It came with scroll updates I believe going up to about 1960, so it may have the data needed for all of the 50s television tubes. Finally, I have a commercial tube tester like we used to see in stores. Luckily this one is a table top model! It needs electronic work, but is all there. I would give that one to anyone who would pick it up and give it a good home!

[Tubejunke]

Originally Posted by Magnavox300

I have read that tubes rarely go bad, but I was wondering if they get worn?
Do new tubes work better? Or when they go bad, are they simply done-
Magnavox300

I must ask where you would have read that information on electron tubes! They most certainly do go bad and I guess you could call it worn. A new tube would certainly do better than a bad one as the bad tube is going to cause whatever circuit that it is being used in to not work properly, if at all. One big reason for the general demise of the electron tube in consumer electronics was the necessity of replacement occasionally which back in time was a normal part of owning a radio or television; hence the TV repairman who often did house calls for a reasonable fee. As time went on tube testers were placed in retail outlets like drug stores, dime stores, and later Radio Shack for do it yourself customers. Normally there was a good stock of new tubes in the shelf space below under lock and key. The invention of the transistor and thus "solid state" radio and TV more or less sealed the fate of the tube as a main stream electronic component as solid state equipment consumes less power and transistors generally don't wear out, at least not in the same way as the tube. Most people think that the tube is completely obsolete, but that is far from true. Today the best high end home audio equipment and music instrument amplifiers are tube driven. Hands down, there are just some things that a tube can accomplish that a nasty little transistor can't!

[Phil Nelson]

I'm in the same camp as bob91343. An inexpensive emission type tester will get the basic job done, which is to weed out duds. You can spend loads of $$$ on a fancy tester, but it won't necessarily help you restore the average TV any faster.

Vintage testers may need the same level of restoration as any other vintage device. I favor something new enough to be reliable, since I to use the tester as an everyday tool, not as a collectible that you dust off and play with once or twice a year.

Certain tube functions (notably, oscillation) can't be tested reliably by a tester. Also, in a surprising number of cases, a so-called "weak" tube will perform just as well as a brand-new one. Testers are useful, but don't get the idea they will tell you everything about every tube in every possible application.

Just my $0.02.

Phil Nelson

[cwmoser]

I use a Precision 10-12 tube tester.
Its a nice looking quality instrument.
Not expensive like the Hickoks.
Covers a wide range of tubes.
Only has one or two capacitors that needs replacing and
the calibration procedure is online.

Carl

[old_coot88]

Originally Posted by Phil Nelson

...Certain tube functions (notably, oscillation) can't be tested reliably by a tester. Also, in a surprising number of cases, a so-called "weak" tube will perform just as well as a brand-new one. Testers are useful, but don't get the idea they will tell you everything about every tube in every possible application.

Just my $0.02.

An old service adage:
The best tube tester is the equipment it's used in.
A tube tester is most useful in an auxillary, confirmatory role. Or for a 'go/no-go' weeding of large batches of tubes.

[Phil Nelson]

Originally Posted by old_coot88

An old service adage:
The best tube tester is the equipment it's used in.
A tube tester is most useful in an auxillary, confirmatory role. Or for a 'go/no-go' weeding of large batches of tubes.

Amen. I use my tester (a cheap Sencore "Mighty Mite") once at the beginning of each project, to quickly check the existing tubes and weed out bad ones. After that, it goes back onto the shelf until the next project.

I own other testers (including a Precision 10-12), but they are collectibles, not workhorses.

Phil Nelson

[Mal Fuller]

Suggestions regarding the better dynamic mutual conductance type testers are certainly valid, but the old Sencore "Mighty Mite" emission testers with Sencore's sensitive grid-leakage test would often ferret out troublemaking tubes that the premium dynamic mutual conductance testers would pass as okay.

[snelson903]

i have b& k & a knight old heathkit had good luck with all three the b&k 667 impress me its really the only peace of test equitment that went through the flood in 96 and servied it was under 3 feet water and took it out cleaned it up let dry and still works they must have really sealed gage on that water never got inside,i was amazed

[Tubejunke]

This is a very informative thread! Great job to all!