Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Tube Testers?

I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric
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On 2019/10/11 5:37 p.m., wrote:
I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric


Well, having easily half a dozen tube testers in my shop may suggest
that I am biased, but really, how can you NOT have a tube tester if you
are using tube equipment? Short of having only a few tube devices, and
knowing what the parameters should be for each tube in those circuits if
working properly (resistors good too!) so that you could use a volt
meter only, a tube tester can take a lot of the guesswork out.

Mutual conductance testing is ideal (and most expensive type of tester)
and the drug-store go/no go testers are at the bottom. The decision is
driven by your budget and how often you are likely to need the thing.

If you are frustrated when trying to fix an amp or radio because you
don't' know if the tube(s) are the cause, then you need to spend the money.

Tube testers are quite robust, so they rarely need service. Usually just
a switch or tube test socket goes bad so pretty easy to deal with.

Get schematics for whatever tester you choose!

Oh, and get a scope at the same time. And a signal generator. And a cap
tester...

John :-#)#
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Default Tube Testers?

wrote:

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


Anyway, time to get to the point. 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.



** 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.

FYI:

Not long ago, I designed a special power valve tester that, along with a few common bench items, allows operation of audio power valves under realistic and even more severe conditions with *everything* adjustable.

It can both sort out tubes with ANY kind of fault and match sets under conditions as found in commercial amplifiers as well.

Nothing on the market like it exists, anywhere.

Cos me SFA to make too.

https://sound-au.com/project165.htm


..... Phil





...... Phil


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Default Tube Testers?

On 10/11/19 8:28 PM, Phil Allison wrote:
In 50+ years of working with valve gear, I have never
used one and know no-ne here in Sydney who does.


I have a few, but usually just to satisfy my curiosity.

Not long ago, I designed a special power valve tester


An excellent bit of kit sir.

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Fox's Mercantile wrote:

-------------------------
Phil Allison wrote:

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


I have a few, but usually just to satisfy my curiosity.

Not long ago, I designed a special power valve tester



An excellent bit of kit sir.


** Nice of you to say so.

FYI:

My colleague Rod took a few liberties when he edited my submitted article.

He added extra circuits of his own, that he had merely simulated and did not build - he has never seen the prototype shown in the pic that I use here.

Mine is very simple, it uses only external PSUs - the 6.3V comes from a variable 5A DC bench supply and negative bias from another 2A one.

There is no "test" button as there is an on/off switch on the front of my 240/240 isolation tranny.

The only known trap is if you hastily hot switch from from pentode back to triode mode - as the latter requires way more negative grid bias. Normally just pops the fuse.

I soon found that most 6BQ5s could be pushed way more than usually seen in pentode mode - with plate and screen voltages of up to 640V and 320V respectively.

So I built a simple output stage that employed a push-pull pair that way and got a remarkable 60W rms of clean power with no sign of red plating !!

Having long ago gone through all my junk box valves, the tester is mainly used for brand new ones, soon as I get them, in case I find a dud or one well out of match. I have even had one or two with the glass broken !!

If I need to return a bad valve, there is way less hassle if I do so the same or next day.

I also added a banana socket to the rear of the box allowing a short top cap lead to be fitted for types like the 6CM5 and 6DQ6B. A few Aussie made guitar amps from the 1960s used them.



..... Phil
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In article ,
says...
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?



The tube tester is not of very much use, especially to someone that is
not in the repair business. For those that are, they will usually have
a stock of new tubes and it is quicker to just pop one in to see if it
solves the problem.

There are 2 basic types in common usage. One is the simple emission
tester. It connects most of the elements together except the cathode
and checks as to how much the cathode will put out. That will often
tell if the tube is weak. The other is the mutual conductance tester.
It simulates a circuit and is better.

Most have a shorted element test where you plug in the tube and tap it.

They do not usually need calibration. The easiest way to tell is to
check several new tubes and see if they show way up in the good reagon.

Tubes are usually the last components to go bad unless another component
causes them to go bad or the filament opens up which an ohm meter will
tell.

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On Fri, 11 Oct 2019 18:10:53 -0700, John Robertson
wrote:

On 2019/10/11 5:37 p.m., wrote:
I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric


Well, having easily half a dozen tube testers in my shop may suggest
that I am biased, but really, how can you NOT have a tube tester if you
are using tube equipment? Short of having only a few tube devices, and
knowing what the parameters should be for each tube in those circuits if
working properly (resistors good too!) so that you could use a volt
meter only, a tube tester can take a lot of the guesswork out.

Mutual conductance testing is ideal (and most expensive type of tester)
and the drug-store go/no go testers are at the bottom. The decision is
driven by your budget and how often you are likely to need the thing.

If you are frustrated when trying to fix an amp or radio because you
don't' know if the tube(s) are the cause, then you need to spend the money.

Tube testers are quite robust, so they rarely need service. Usually just
a switch or tube test socket goes bad so pretty easy to deal with.

Get schematics for whatever tester you choose!

Oh, and get a scope at the same time. And a signal generator. And a cap
tester...

John :-#)#

I already have a Tek 465B and a BK 4MHz function generator. No cap
tester yet.
Eric
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On 2019/10/12 10:35 a.m., wrote:
On Fri, 11 Oct 2019 18:10:53 -0700, John Robertson
wrote:

On 2019/10/11 5:37 p.m.,
wrote:
I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric


Well, having easily half a dozen tube testers in my shop may suggest
that I am biased, but really, how can you NOT have a tube tester if you
are using tube equipment? Short of having only a few tube devices, and
knowing what the parameters should be for each tube in those circuits if
working properly (resistors good too!) so that you could use a volt
meter only, a tube tester can take a lot of the guesswork out.

Mutual conductance testing is ideal (and most expensive type of tester)
and the drug-store go/no go testers are at the bottom. The decision is
driven by your budget and how often you are likely to need the thing.

If you are frustrated when trying to fix an amp or radio because you
don't' know if the tube(s) are the cause, then you need to spend the money.

Tube testers are quite robust, so they rarely need service. Usually just
a switch or tube test socket goes bad so pretty easy to deal with.

Get schematics for whatever tester you choose!

Oh, and get a scope at the same time. And a signal generator. And a cap
tester...

John :-#)#

I already have a Tek 465B and a BK 4MHz function generator. No cap
tester yet.
Eric


If you can find an old EICO or Heathkit component tester
(Resistors/Caps/Inductors - using a Wheatstone Bridge) with the "Magic
Eye". They are great for reforming caps (they go up to 600V if I am not
mistaken) and the Magic Eye is a nice touch.

John :-#)#



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www.flippers.com
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Default Tube Testers?

On Sunday, 13 October 2019 01:19:38 UTC+1, John-Del wrote:
On Saturday, October 12, 2019 at 3:45:58 PM UTC-4, tabby wrote:
On Saturday, 12 October 2019 19:30:38 UTC+1, Ralph Mowery wrote:


You may want to look into getting one of the roughly $ 20 component
testers from China. They do a good job of testing many solid state
devices, inductors, capacitors and resistors. Plenty of them on ebay.


Very handy little things. No reforming function as yet.



Won't be easy to reform caps without a wee bit more voltage than a 9V battery can supply. Besides, if a cap needs reforming, it's best to not use it.


a non-challenge to step it up onboard.

You never know it might appear one day, but I'm not optimistic. And the one I have can't do in-circuit testing, nor C versus V info. But it does give C, ESR & loss with a single button press.


I bought one because I couldn't resist it for the price, but I find it wildly inaccurate for low value resistance and low value capacitors. I found a calibration procedure on-line that uses a small value cap for a reference, but it only made it worse.

Does identify terminals in transistors accurately though.


No-one would accuse them of being quality items, but very handy nonetheless. I hear there is a new version now & then with ever more functionality.


NT
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On Sunday, 13 October 2019 19:23:59 UTC+1, Ralph Mowery wrote:
In article ,
tabbypurr says...

I bought one because I couldn't resist it for the price, but I find it wildly inaccurate for low value resistance and low value capacitors. I found a calibration procedure on-line that uses a small value cap for a reference, but it only made it worse.

Does identify terminals in transistors accurately though.


No-one would accuse them of being quality items, but very handy nonetheless. I hear there is a new version now & then with ever more functionality..




What is interisting is a company called Peak makes several versions for
around $ 100. The cheat people that are not informed. One device only
tests the solid state devices and the other tests restiors, capacitors
and inductors. That way you are forced to buy two of the units.

They are practically the same as the all in one $ 20 device in a fancy
case.

They are not lab quality instruments but for $ 20 they work very well at
the hobby grade.

As far as forming capacitors, if the capacitor is over 20 years old and
there is any doubt, just replace it.


A lot of people have that approach. Whether replacing sound historic caps with new ones that likely won't last is a good plan is debated.


I have read that new capacitors
are formed at the factory at a slightly higher voltage because they will
deterioate just sitting on the shelf. Those may be worth while bringing
the voltage up slow on if they have been on the shelf for a long period
of time


same happens to old caps. Doesn't mean they're dud.


NT


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RANT WARNING!

On tube testers - with the exception of very modern testers that will plot curves on a PC, effectively there are two types of testers and within each type, two tiers.

A top-tier emissions-tester is good for 99-44/100ths of most hobby uses. It is, for the record, very nearly as good as a second-tier GM tester. Better in some few cases.

A top-tier emissions tester will also test (reasonably accurately) for "SHORTS" and "GAS" - which functions are what separate a tester from the device itself. Reject any tester out of hand if it does not do shorts and gas. It is useless in actual practice. A Heath TC-2/3 and many others will meet the most basic needs of the hobbyist. Prices for Emissions-Only testers are, perhaps, 20% of the price of a GM tester, all other things being equal.

A standard GM tester will also test for shorts and gas - some better than others. By virtue of being a GM tester, such a unit will give a RELATIVE indication of actual tube quality against a narrow set of fixed parameters. That information is very nearly useless *unless* one has known-good tubes with which to compare readings.

Now, a top-tier GM tester (and there are very, very few) will allow one to set bias, read filament current, plate current, and - thereby - allow one to actually match tubes accurately. An example of such would be the Hickok 539 series. But NOT (emphatically) a TV7, however popular and expensive it might be.

Unless one is seriously into audio and has an actual need to match tubes and/or do qualitative testing, don't waste your money on such a tester. And, if one is as deeply in as all that, look into the modern testers with curve-tracers and so forth. Big bucks. Or, if, as I did, you should trip over a fully calibrated 539B, grab it. But, at the going rate of $1,000 and up, not so much.

Now, on WHY:

A tube with a short - especially a thermally dependent short can do great harm if it fails in-situ and without the operator right there with the instant shut-down device. A slagged rectifier tube, for instance, can take out a power-transformer in seconds. And why it is that a certain tubes should be tested for some time on a tester to look for thermal faults. Open filaments are seldom a threat, but shorts really, really are. And, a thermal short will NOT show up with a VOM testing at the pins.

A tube tester is handy. It allows one to develop a stock of good, trustworthy tubes such that when 'at work' one may simply substitute-and-test-later without agonizing. One also avoids cascade-effects, where a series of weak tubes give symptoms not attributable to any one (or two) tubes. A good example of such would be a multi-band radio that is perfectly fine on AM, but weak on SW, or silent on FM, if so-equipped.

So, Eric, out there on your island - if you want a tube tester, DO NOT go out there on eBay. DO go either to a trusted dealer - there are several - and expect to pay a premium for a good, clean, warranted device. OR, go to a trusted friend who is more in harm's way than you might be, and use him/her as a bird-dog for you. At Kutztown, there are never less than 30 - 50 tube testers on-offer, of which more than 80% of them are not worth the cost of plugging them in. Of the remaining 20% most of them are too much work to make reliable. Of those few remaining, they can be gems. But, I would guarantee that if one were to attend two sequential events, and have a budget of $200 or so (inclusive of shipping), one would wind up with a fully functional device with the correct literature to cover most of the tubes you will encounter in this hobby.

End Rant

Some other points:

a) An individual primarily working with instrument amplifiers as an example, will have a very limited universe of tubes to test. For that individual, a full-range tester will be heavily compromised due to its all-things-to-all-people requirement. That person needs a specialty tester. Those who routinely use, maybe, 10 kinds of tubes, but whose collection uses well over 200 kinds of tubes might be a bit hamstrung by a specialty tester.

b) There are those here that are genuinely dangerous, and should be strung up by their thumbs from the nearest lamppost for the advice they give. Have the wisdom to discern the issues involved.

c) And there are those here with specific prejudices, peculiarities and expectations - some more hostile than others. I more-or-less fit into this category at times. Same advice as above.

Peter Wieck
Melrose Park, PA


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On Sunday, 13 October 2019 22:36:21 UTC+1, Fox's Mercantile wrote:
On 10/13/19 3:39 PM, tabbypurr wrote:
On Sunday, 13 October 2019 19:23:59 UTC+1, Ralph Mowery wrote:


As far as forming capacitors, if the capacitor is over 20 years
old and there is any doubt, just replace it.


A lot of people have that approach. Whether replacing sound
historic caps with new ones that likely won't last is a good plan is debated.

NT



And still, you persist in this stupidity.
Quality electrolytics these days are quite reliable and long
lived. Unless you're buying cheap counterfeits from China.

I've been repairing (which includes blanket recaps) for the
past 25 years now, I have yet to have a customer bring back a
radio because a cap failed.


That's one side of the recap all or not debate, and of course new caps don't fail in short order. The OP is free to find out why some of us don't do that. I tire of your stupidity.


NT
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peter wieck who has a serious mental disability wrote:

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

RANT WARNING!



** Nice warning - plus thoroughly needed.


( snip the whole stupid lot )



Some other points:

a) An individual primarily working with instrument amplifiers as an example, will have a very limited universe of tubes to test. For that individual, a full-range tester will be heavily compromised due to its all-things-to-all-people requirement. That person needs a specialty tester.


** That person needs to BUILD their own as none exist already.

Or, do as has been done by technicians ever since the invention of radios and TV sets - use the item under repair as the tube tester.

Conditions met in commercial equipment regularly exceed the ones built into so called tube testers - most of which are useless when it comes to revealing common faults and shortcomings in particular tubes that show up readily when placed into actual service.

** Makers of various tube testing devices DO NOT claim the miraculous abilities that so many ****wit owners of them try to claim. **



b) There are those here that are genuinely dangerous, and should be
strung up by their thumbs from the nearest lamppost for the advice they give.


** Boy oh boy - is Mr Weaky ever one of them.

Dangerous, mostly because the geriatric fool has NO ****ing idea how mindlessly arrogant and stupid he is.



..... Phil
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You are to be pitied, sadly.

But, respected, not so much.

Peter Wieck
Melrose Park, PA
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On Sun, 13 Oct 2019 13:39:57 -0700, tabbypurr wrote:

A lot of people have that approach. Whether replacing sound historic
caps with new ones that likely won't last is a good plan is debated.


Absolutely. I've just tested some big old electros that are well over 40
years old and they're all *totally* fine by any measure. Good, high
quality manufacturers of the day and built to last. I would not want to
take a chance on replacing them with new stuff that could be fake from
the far East. In fact I don't even trust new electros from formerly
respected manufacturers if they've turned production over to places like
China.



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On Fri, 11 Oct 2019 17:37:17 -0700, wrote:

Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.


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.


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On Monday, October 14, 2019 at 9:28:08 PM UTC-4, Phil Allison 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.



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 several 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 as this for advice and guidance
c) OP is curious, would like to know more, and would like to be as reasonably 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 suggestions 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 beneath.
g) The OP seems to have the most basic tools, such as a VOM and so forth. Whether an LCR, ESR, or other meters/testers should come before a tube tester - which would be my suggestion in general - we have no specific idea of this individual's discretionary income.
h) And none of us are fit to render judgment on the OP's competence. However, as a simple difference between him and you - wisdom comes with age, stupidity 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 choices and implications. Even the simple ones are complicated devices wherein a lot can go wrong, and wherein there are vanishingly few individuals around competent to service them. And, the brute fact of the matter is that they 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. Tubes, 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 within 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 twice a year at Kutztown. My Hickok tube tester came to me through a GE production engineer who worked at their Re-Entry Systems Division in West Philadelphia.

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 advice 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
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Default Tube Testers?

On Tuesday, October 15, 2019 at 8:50:42 AM UTC-4, wrote:
On Monday, October 14, 2019 at 9:28:08 PM UTC-4, Phil Allison 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.



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 several 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 as this for advice and guidance
c) OP is curious, would like to know more, and would like to be as reasonably 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 suggestions 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 beneath.
g) The OP seems to have the most basic tools, such as a VOM and so forth. Whether an LCR, ESR, or other meters/testers should come before a tube tester - which would be my suggestion in general - we have no specific idea of this individual's discretionary income.
h) And none of us are fit to render judgment on the OP's competence. However, as a simple difference between him and you - wisdom comes with age, stupidity 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 choices and implications. Even the simple ones are complicated devices wherein a lot can go wrong, and wherein there are vanishingly few individuals around competent to service them. And, the brute fact of the matter is that they 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. Tubes, 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 within 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 twice a year at Kutztown. My Hickok tube tester came to me through a GE production engineer who worked at their Re-Entry Systems Division in West Philadelphia.

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 advice 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


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 situations where tubes characteristics are different and even a new one may not work - but that is very remote possibility)
If your objective is to gain knowledge and apply it to servicing other types of equipment, then getting a 'middle of the road' tester is probably worth 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 (not engineering shops)Last I checked, a working one on fleabay was around $100 USD.
What is difficult to say (because it has been a long time for me) is the number of different types of tubes one can test and their distribution in various 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, middle 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 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 conditions of the tube to see what is really going on. Great learning opportunity, time consuming, an you would probably need a tester with a great deal of functions.
good luck in your quest.

-j
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On Tuesday, October 15, 2019 at 2:47:03 PM UTC-4, wrote:

Snippage


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 set, each one being an opportunity to make a mistake, or many sockets instead - which slightly reduces error opportunities, but proportionately increases the size of the device.

You can always sell the tester if it doesn't meet your need or you go in 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.

As far as guidance, the more knowledgeable ppl here can cite low-end, middle 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 compactrons. Adaptors are available, but scarce and costly.

Tube testing is not always a go/no go result. The value of a number of 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 conditions of the tube to see what is really going on. Great learning opportunity, time consuming, an you would probably need a tester with a great deal of functions.


Never 100% go, but certainly what is a No-Go will absolutely be a No-Go (shorts 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 tuners, one works in only one tuner. All three of them test fairly close together on the Hickok 539B.

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

Go figure.

good luck in your quest.


Indeed!

Peter Wieck
Melrose Park, PA

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In article ,
says...
f your objective is to gain knowledge and apply it to servicing other types of equipment, then getting a 'middle of the road' tester is probably worth 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 (not engineering shops)Last I checked, a working one on fleabay was around $100 USD.



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.



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A Pathetic Old ****head called wrote:

--------------------------------------------------
Phil Allison 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.



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


** Translation - Phil can read an interpret English.


( snip great big pile of smelly horse manure)



So, if the OP is inquiring after tube testers,


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


ours is to advise on the choices and implications.



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


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



** 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


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In article ,
wrote:

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
tuners, one works in only one tuner. All three of them test fairly close together on the Hickok
539B.

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

Go figure.


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.
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On Saturday, 12 October 2019 01:32:14 UTC+1, wrote:
I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. 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. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric


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.



https://www.dos4ever.com/uTracer3/uTracer3_pag1.html
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