Oldschool tubes

Not exactly a sophisticated piece of test equipment, but lets you eject bad metal enclosure tubes early:

(all the metal tubes in the 1935 table radio passed)

Reply to
bitrex
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Can you not take the photo in daylight? Could barely make out the outline of the tester.

I assume it is a go/no-go style, and perhaps verifies if the filaments are good. Can't imagine it doing much else...

Of course, one can tell if the filaments are good if the tube warms up in the set, so if that is all it is then it is an early audio-phool tool.

John

Reply to
John Robertson

A common as dirt filament tester. They were common as dirt, and sold for about $3 in the early '60s. They hyped as real tube testers.

Reply to
Michael A Terrell

"It Does What It Says on the Tin"

Reply to
bitrex

Just like the cans of 'Replacement Vacuum'?

Reply to
Michael A Terrell

How do I get the vacuum out of the can and back in the tube, though?

Reply to
bitrex

I am just barely old enough to remember "tube testers" in some stores like Western Auto, ACE Hardware, etc... They were quickly becoming obsolete.

On the other hand, I am old enough to remember (somewhat vividly) when the MOS Technology 6502 came out.

Reply to
mpm

I'm old enough to remember that, in my early teens, it was my assignment in my father's TV repair shop to test all the tubes on sets incoming for repair ;-) ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

That was explained on the tin, not in the ads.

Reply to
Michael A Terrell

Tube testers came as

Filament test

Emission (basically see some plate current)

Gas (grid current)

Shorts

"Mutual conductance" with real AC signals

There were transistor testers for a while, but they went away.

--
John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  
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Reply to
John Larkin

Ah, the good old days. Real radios glow in the dark.

Reply to
sdy

I don't feel much like buying an old-timey tube tester, I don't havea lot of space in the lab, they're bulky and I wouldn't usually have much use for it - tubes are kinda cool but I'm not an obsessive and don't do much with them usually.

I can check for shorts with a DMM, for emission and mutual conductance I can probably just put 'em in a socket and wire up the standard CC circuit in the datasheet, using one of the variable high voltage boost converter modules I have on hand, feed with signal generator and see what happens

Reply to
bitrex

Actually for emission it would probably be easiest to wire them as common plate with the plate directly to a HV supply and rig up a bench supply as a constant current cathode load and sweep the current

Reply to
bitrex

John Larkin wrote on 11/9/2017 8:44 PM:

There are transistor testers on many voltmeters. A six (or maybe more, I don't have one here to look at) pin socket lets you plug in a transistor of any configuration (EBC, BEC, etc) and I think the gain is shown. But I have never used that feature, so I'm not sure I'm remembering it right.

--
Rick C 

Viewed the eclipse at Wintercrest Farms, 
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Reply to
rickman

Shorts don't always show up until you load the tube (or tap it). You can also get leakage and other odd things (microphonics, etc.) that the better tube testers would show. Yes you can make some test gear in your shop, but how do you get a standard unless you have several NOS tubes to compare to? We do repair tube gear and so have to have a couple of tube testers in our shop - mutual conductance is our preferred machine.

As our work is on arcade games and jukeboxes from the first to the most recent we have test gear going back to the 40s right up to current. Everything from armature growlers, Fluke 9010s w/8 & 16 pit pods, PROM/EPROM programmers from 1702s up to 8mb devices (so far), Hard drive duplicator, injection molder, 3D printer, dynamic RAM tester (4116s and friends), and on and on.

At least it is fun to go to work!

John

Reply to
John Robertson

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

** I still do a lot of work with valves (tubes if you are a Yank) but have never thought buying a "Tube Tester" worthwhile. They simply do not carry out tests needed for audio service or production.

The best way to test a tube is to into plug it into a known working piece o f gear and put it through it paces. Another way is to replace a suspect tub e with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Mete r" I designed and built my own tube tester that would perform all the neede d tests at least as far as common 8 and 9 pin output tubes were concerned.

Using a very simple circuit plus basic bench equipment, it puts a power tub e under realistic operating conditions and finds if it working normally. Al so matching the performance and idle bias settings for sets of tubes to be used in parallel is easily accommodated. The beauty of the method used is t he tube operates under low duty cycle conditions so plate and screen dissip ation limits are not approached or exceeded.

I find most use for the tester is with newly purchased tubes, to see if the y are up to spec or not.

MY colleague, Rod Elliot, published the design on his web sight as Project

165 in February last year.

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The many warnings are justified, valve testers can destroy valves.

.... Phil

Reply to
Phil Allison

Any thoughts on this "We used a PIC!" China special tube tester kit?

Reply to
bitrex

I like that idea. Did you have to wear a space-suit in case any vacuum got spilled?

Mike.

Reply to
Mike Coon

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

** No, but there were were a few mysterious disappearances among regular users.

Hence the expression "getting canned" .....

.... Phil

Reply to
Phil Allison

I still want my Acme Portable Hole.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
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Reply to
Phil Hobbs

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