Tube Testers?

Having worked on tube gear for well over 50 years, YES, you need a tube tester, unless you want to stock replacement tubes for everything you work on (not very practical). But you want a good quality tester. They used to actually sell tube testers that did nothing but check if the filament worked. Very useless. If the filament lights in the radio, the filament works. Or use an ohm meter.

Back in my youth, drug stores had tube testers. Some did a halfway good test, while others were pretty useless. But it gave you something to do while the pharmacist spent an hour putting 20 pills in a bottle. Then you went home, took your drugs and got too stoned to remember which tube was the bad one. :)

I have three tube testers. All are very old. Yet they still work well. The biggest problem with all of them are the paper roll charts. They fall apart from age. Most of the data on them is available online. You can either spend a lot of time making your own roll chart, or just print individual sheets, punch holes, and put then in a notebook.

Buying an old RCA or GE or other brand tube manual is needed too. Or you can now download them for free in .PDF format. Search for "RCA tube manual" or similar.

----------------------------- snipped-for-privacy@whidbey.com wrote:

** The OP is not going into the servicing business.

He has exactly one, old tube radio with no clue how to work on it.

A tube tester is the LAST thing he needs to spend money on.

..... Phil

It must be very difficult for you to be such a paragon of perfection and to be endowed with such god-like powers.

From what I am gathering, and from seeing the OP's posts over the last seve ral years, this hobby is becoming more serious and involved as time goes on . So, let's look at this from down here on earth, not from Mt. Olympus such as is your personal kingdom:

a) OP is in the Pacific Northwest, and not even in Downtown Vancouver. AKA

- isolated. b) OP is pretty much dependent on shipping, the internet, and venues such a s this for advice and guidance c) OP is curious, would like to know more, and would like to be as reasonab ly self-sufficient as practical. d) OP is not restricting himself to a single path or interest. e) OP is starting to "tool up" into the hobby, and is looking for suggestio ns on what to do. f) Gone are the days when very nearly every drugstore and hardware store in North America had a tube tester up front with a cabinet full of tubes bene ath. g) The OP seems to have the most basic tools, such as a VOM and so forth. W hether an LCR, ESR, or other meters/testers should come before a tube teste r - which would be my suggestion in general - we have no specific idea of t his individual's discretionary income. h) And none of us are fit to render judgment on the OP's competence. Howeve r, as a simple difference between him and you - wisdom comes with age, stup idity lasts forever. You are absolute and irrefutable proof of the latter.

So, if the OP is inquiring after tube testers, ours is to advise on the cho ices and implications. Even the simple ones are complicated devices wherein a lot can go wrong, and wherein there are vanishingly few individuals arou nd competent to service them. And, the brute fact of the matter is that the y are capable of saving a great deal of time, and over time will at least r ecover much of their cost based on throughput and avoided blind alleys. Tub es, these days and in onsies/twosies are not cheap. The OP does not have a twice-annual Kutztown on-offer. The OP is not based in the center of tube p roduction (RCA/Sylvania/Raytheon/Philco/GE all produced their tubes within

300 mile from where I sit, with Philco, RCA and Sylvania within 60 miles. O ne of RCA's chief designers lives less than 4 miles from me. We meet twice a year at Kutztown. My Hickok tube tester came to me through a GE productio n engineer who worked at their Re-Entry Systems Division in West Philadelph ia.

My point is that stuff is thick on the ground where I am. I DO NOT have to depend on shipping and the Internet for my sources. And I do not need advic e from the likes of you, however otherwise technically adept you might be.

Go service something, you are useless here on this thread.

Peter Wieck Melrose Park, PA

to be endowed with such god-like powers.

veral years, this hobby is becoming more serious and involved as time goes on. So, let's look at this from down here on earth, not from Mt. Olympus su ch as is your personal kingdom:

A - isolated.

as this for advice and guidance

ably self-sufficient as practical.

ions on what to do.

in North America had a tube tester up front with a cabinet full of tubes be neath.

Whether an LCR, ESR, or other meters/testers should come before a tube tes ter - which would be my suggestion in general - we have no specific idea of this individual's discretionary income.

ver, as a simple difference between him and you - wisdom comes with age, st upidity lasts forever. You are absolute and irrefutable proof of the latter .

hoices and implications. Even the simple ones are complicated devices where in a lot can go wrong, and wherein there are vanishingly few individuals ar ound competent to service them. And, the brute fact of the matter is that t hey are capable of saving a great deal of time, and over time will at least recover much of their cost based on throughput and avoided blind alleys. T ubes, these days and in onsies/twosies are not cheap. The OP does not have a twice-annual Kutztown on-offer. The OP is not based in the center of tube production (RCA/Sylvania/Raytheon/Philco/GE all produced their tubes withi n 300 mile from where I sit, with Philco, RCA and Sylvania within 60 miles. One of RCA's chief designers lives less than 4 miles from me. We meet twic e a year at Kutztown. My Hickok tube tester came to me through a GE product ion engineer who worked at their Re-Entry Systems Division in West Philadel phia.

o depend on shipping and the Internet for my sources. And I do not need adv ice from the likes of you, however otherwise technically adept you might be .

Like most things in service and design of electronic systems (and others), the answer is 'it depends'. The best we can do is provide objective guidance and not absolutes because he needs to understand the trade-offs. From his back ground, sounds like a concept he is familiar with.

In general: If you only are dealing with one thing to service, probably cheaper to buy a set of tubes and change out the old ones. (BUT I've experienced situation s where tubes characteristics are different and even a new one may not wor k - but that is very remote possibility) If your objective is to gain knowledge and apply it to servicing other type s of equipment, then getting a 'middle of the road' tester is probably wort h it. But it depends on the financial risk you want to take. From my experience, B&K 700 and 707 were fairly standard in repair shops (n ot engineering shops)Last I checked, a working one on fleabay was around $1

00 USD. What is difficult to say (because it has been a long time for me) is the nu mber of different types of tubes one can test and their distribution in var ious electronic devices. I have a portable that has 6-8 sockets in it. I have the B&K 700 that has maybe 15-18 sockets in it. I am rebuilding it and the small tester I have works fine for my needs. You can always sell the tester if it doesn't meet your need or you go in a different direction in your hobby. As far as guidance, the more knowledgeable ppl here can cite low-end, middl e of the road, and high end units for you to evaluate.

Tube testing is not always a go/no go result. The value of a number of tu be characteristics can combine to make the tube 'questionable' In these si tuations, the most expedient way to fix the problem is with a new tube. So me ppl may want to get into the details and tease apart the operational con ditions of the tube to see what is really going on. Great learning opportu nity, time consuming, an you would probably need a tester with a great deal of functions. good luck in your quest.

-j

I have the B&K 700 that has maybe 15-18 sockets in it. I am rebuilding it and the small tester I have works fine for my needs.

This is a nice segue into whether a tester wants to have many switches to s et, each one being an opportunity to make a mistake, or many sockets instea d - which slightly reduces error opportunities, but proportionately increas es the size of the device.

a different direction in your hobby.

Yes. I find that they are a slowly appreciating asset, and as time goes on, working examples are fewer and fewer.

dle of the road, and high end units for you to evaluate.

Yes, and the key here is also how far "Back" any given tester goes (all the way back to 4-pin devices), or not, and will it do such things as compact rons. Adaptors are available, but scarce and costly.

tube characteristics can combine to make the tube 'questionable' In these situations, the most expedient way to fix the problem is with a new tube. Some ppl may want to get into the details and tease apart the operational c onditions of the tube to see what is really going on. Great learning oppor tunity, time consuming, an you would probably need a tester with a great de al of functions.

Never 100% go, but certainly what is a No-Go will absolutely be a No-Go (sh orts or gassy tube, open filament, and so forth).

On your point of 'even a new tube'.... there are two such tubes out there, being the 19T8 and the 6AQ8 that can be quite annoying. At this moment, I keep three (3) Dynaco FM3 tuners, and I have a total of five (5) 6AQ8 tubes available to me. Of the five, two work in all tuners. Two work in two tune rs, one works in only one tuner. All three of them test fairly close togeth er on the Hickok 539B.

And, I have two radios using a 19T8 in the FM section. And four (4) such tu bes. None of them work in both tuners. All of them work in one-or-the-other tuner.

Go figure.

Indeed!

Peter Wieck Melrose Park, PA

Seems like the ebay price has gone way up on the testers now. Most worth while are in the $ 300 and up including shipping.

A person can buy a lot of new old stock tubes for that.

Sometimes one can get lucky. I bought one at a hamfest a month a go for $ 55. It in the mutual conductance type. It was made around 1950. It did come with an adaptor and book for many of the more modern tubes. Interisting way to check the multielement compactrons. There is a special socket that allows the tube to be rotated so that the 9 wires from the tester can be placed on all the elements, just not all at the same time.

I don't really like to use a tube tester, but just thought it would be something to play with after not having one for about 50 years.

Most of the time it is quicker for me to takea few voltage readings and resistance readings and feed a signal in to the circuit. I have found on many of the older electronics to suspect the capacitors and carbon resistors first. If a tube lights up , it is seldom bad if the getter is bright silver.

-------------------------------------------------- Phil Allis>

** Translation - Phil can read an interpret English.

( snip great big pile of smelly horse manure)

** Fraid that is not what the OP posted at all.

** The OP asked a quite different question - you PITA, OCD f***ed, lying idiot.

** Unlike the autistic Weaky old farf - I am far more use here that he has ever been.

I warned the OP this would happen if he even mentioned the magic words.

** The OP's question:

" How valuable is a tube tester for someone who is only, or mainly, going to be messing with audio gear and the gear for testing audio gear."

Phil's insightful reply:

------------------------------------------------------------

** IME - no use at all.

In 50+ years of working with valve gear, I have never used one and know no-ne here in Sydney who does.

What you NEED is a supply of known good valves to use as substitutes.

The item itself is your "tube tester" and a far better one that anything you can buy - cos it operates the valves under *actual service conditions*.

Others here will say differently, cos they own one of more of the stupid things and *love* them irrationally, like pets.

-----------------------------------------------------------------------

.... Phil

From what I've read, this is an "often-told tale" - not at all uncommon. "Synergy, or lack thereof" seems to be the issue in a lot of cases.

That is to say, the radios aren't identical. Differences in the characteristics of the other tubes, drifted resistors which affect biasing, etc. make them different, so what the radio may "want" from the tube in question differs.

Some radios (some circuits, rather) are more tolerant of tube parameter variations. Others are finicky... sometimes people take shortcuts with e.g. biasing setups, which means that the tube must fall into a particular range of its possible parameter-space in order to work correctly. Worst-case here is if you see a schematic with a lot of "selected" tubes or other components... that can mean that the circuit is sensitive to component value variation. A batch of tubes which all read "good" on the tester (and which all fall well within the manufacturer's specs) may or may not work.

Also, the testers tend to pick one particular set of operating conditions (e.g. plate voltage) for each model of tube. These conditions may differ significantly from the conditions under which the tube actually operates in a particular model of radio.

So, there's a lot of justice behind the "The best tester for a tube, is the device in which the tube was being used" philosophy.

It would be interesting to know how the 19T8 and the

6AQ8 tubes you have, actually measure out on a good firebottle-capable curve tracer... see just how their parameter sets cluster, and correlate that to the radios in which they do and do not work properly.

I built my own from a kit. It works very well, and can supply up to 400v Anode voltage.

Not quite full guitar amp voltage, but probably a whole lot better than most of the vintage testers, which may be well out of spec or just plain broken by now.

It will even superimpose multiple plots on the same graph, so you can see how evenly matched a quad of output valves are, or aren't.