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.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

(all the metal tubes in the 1935 table radio passed)
  #2   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/09 8:14 AM, bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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


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
  #3   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 86
Default Oldschool tubes

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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



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.

  #4   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

On 11/09/2017 05:58 PM, Michael A Terrell wrote:
bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


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



¬*¬* 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.


"It Does What It Says on the Tin"
  #5   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 86
Default Oldschool tubes

bitrex wrote:
On 11/09/2017 05:58 PM, Michael A Terrell wrote:
bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


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



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.


"It Does What It Says on the Tin"



Just like the cans of 'Replacement Vacuum'?



  #6   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

On 11/09/2017 06:24 PM, Michael A Terrell wrote:
bitrex wrote:
On 11/09/2017 05:58 PM, Michael A Terrell wrote:
bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0



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


¬*¬*¬* 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.


"It Does What It Says on the Tin"



¬*¬* Just like the cans of 'Replacement Vacuum'?


How do I get the vacuum out of the can and back in the tube, though?
  #7   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 86
Default Oldschool tubes

bitrex wrote:

Michael A Terrell wrote:

bitrex wrote:

Michael A Terrell wrote:

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.

"It Does What It Says on the Tin"


Just like the cans of 'Replacement Vacuum'?


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



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

  #8   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 30
Default Oldschool tubes

On Thu, 9 Nov 2017 11:14:39 -0500, bitrex
wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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


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

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

  #9   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

On 11/09/2017 08:44 PM, John Larkin wrote:
On Thu, 9 Nov 2017 11:14:39 -0500, bitrex
wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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


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.



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
  #10   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

On 11/09/2017 10:42 PM, bitrex wrote:
On 11/09/2017 08:44 PM, John Larkin wrote:
On Thu, 9 Nov 2017 11:14:39 -0500, bitrex
wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


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


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.



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


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


  #11   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 399
Default Oldschool tubes

John Larkin wrote on 11/9/2017 8:44 PM:
On Thu, 9 Nov 2017 11:14:39 -0500, bitrex
wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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


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.


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,
on the centerline of totality since 1998
  #12   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/09 7:42 PM, bitrex wrote:
On 11/09/2017 08:44 PM, John Larkin wrote:
On Thu, 9 Nov 2017 11:14:39 -0500, bitrex
wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


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


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.



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


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
  #13   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,249
Default Oldschool tubes

John Robertson wrote:

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


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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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


..... Phil


  #14   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/09 8:32 PM, Phil Allison wrote:
John Robertson wrote:

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


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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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


..... Phil



I think I want a AVO VCM163 Valve Characteristic Meter!

John ;-#)#
  #15   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,249
Default Oldschool tubes

John Robertson wrote:

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


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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally.. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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



I think I want a AVO VCM163 Valve Characteristic Meter!



** That is a very ambiguous thing to post.

My design does a whole HOST of things the AVO does NOT - since it is specifically an output tube tester with used defined parameters that one to mimic or exceed actual operation.

The only similarity lies in the use of unrectified AC for screen and plate voltages.




...... Phil







  #16   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/09 10:54 PM, Phil Allison wrote:
John Robertson wrote:

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


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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally.. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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



I think I want a AVO VCM163 Valve Characteristic Meter!



** That is a very ambiguous thing to post.

My design does a whole HOST of things the AVO does NOT - since it is specifically an output tube tester with used defined parameters that one to mimic or exceed actual operation.

The only similarity lies in the use of unrectified AC for screen and plate voltages.




...... Phil


Yes, Phil, it was ambiguous, however we use about forty or more
different types of tubes. And your process above, while it would be
great on high end equipment, is deeper than we would ever need to go for
our jukebox customers. These aren't Macintosh amps - and my staff just
can't take the time to learn a whole new set of testing procedures just
to get the best tube for the job. On the other hand, for the audiophile
who wants the best, your procedure could be useful for them I suspect -
and they would likely be willing to take the time to assemble the gear
to accomplish it.
I need something quicker and easier to use in our shop. Hence the MC
style tube tester which does a pretty good test for most tubes. And when
the results are inconclusive we have swapped tubes from our stock to try
and find the best sounding ones. Pretty subjective at that point, eh?

The AVO looked like a step up from our current 1950s tester...

John :-#)#
  #18   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,249
Default Oldschool tubes

John Robertson wrote:

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



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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally.. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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



I think I want a AVO VCM163 Valve Characteristic Meter!



** That is a very ambiguous thing to post.

My design does a whole HOST of things the AVO does NOT - since it is specifically an output tube tester with used defined parameters that one to mimic or exceed actual operation.

The only similarity lies in the use of unrectified AC for screen and plate voltages.





Yes, Phil, it was ambiguous, however we use about forty or more
different types of tubes.


** Not power tubes you don't.


And your process above, while it would be
great on high end equipment, is deeper than we would ever need to go for
our jukebox customers.



** My customers all own guitar amps, some of them ancient.

So the same need you seem to have.


These aren't Macintosh amps - and my staff just
can't take the time to learn a whole new set of testing procedures just
to get the best tube for the job.



** Not my quest either.

I just need to sort duds out of batches of new or used tubes when I do not have the target amp on hand.


I need something quicker and easier to use in our shop.



** Takes the same time as any tube tester, 60 seconds for the filament to heat and another 60 for the various checks.



Hence the MC
style tube tester which does a pretty good test for most tubes. And when
the results are inconclusive we have swapped tubes from our stock to try
and find the best sounding ones.



** Best sounding?? You on drugs?


The AVO looked like a step up from our current 1950s tester...



** If you can find one, it will likely cost you an arm and a leg.

And do nothing very useful.



..... Phil



  #21   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/10 1:32 AM, Phil Allison wrote:
John Robertson wrote:

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



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.



** 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 of gear and put it through it paces. Another way is to replace a suspect tube with a known good one and see if that changes things.

Recently, inspired by the schem of an old AVO163 "Valve Characteristic Meter" I designed and built my own tube tester that would perform all the needed 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 tube under realistic operating conditions and finds if it working normally.. Also 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 the tube operates under low duty cycle conditions so plate and screen dissipation limits are not approached or exceeded.

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

MY colleague, Rod Elliot, published the design on his web sight as Project 165 in February last year.

http://sound.whsites.net/project165.htm

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



I think I want a AVO VCM163 Valve Characteristic Meter!



** That is a very ambiguous thing to post.

My design does a whole HOST of things the AVO does NOT - since it is specifically an output tube tester with used defined parameters that one to mimic or exceed actual operation.

The only similarity lies in the use of unrectified AC for screen and plate voltages.





Yes, Phil, it was ambiguous, however we use about forty or more
different types of tubes.


** Not power tubes you don't.


True - mostly 6L6, 7868, 6V6, 45, 6973, um...



And your process above, while it would be
great on high end equipment, is deeper than we would ever need to go for
our jukebox customers.



** My customers all own guitar amps, some of them ancient.

So the same need you seem to have.


These aren't Macintosh amps - and my staff just
can't take the time to learn a whole new set of testing procedures just
to get the best tube for the job.



** Not my quest either.

I just need to sort duds out of batches of new or used tubes when I do not have the target amp on hand.


I need something quicker and easier to use in our shop.



** Takes the same time as any tube tester, 60 seconds for the filament to heat and another 60 for the various checks.



Hence the MC
style tube tester which does a pretty good test for most tubes. And when
the results are inconclusive we have swapped tubes from our stock to try
and find the best sounding ones.



** Best sounding?? You on drugs?


No, mostly dealing with microphonics which the tube tester can miss.
6J5s are the biggest culpret, but I've even had them on 12AX7s...



The AVO looked like a step up from our current 1950s tester...



** If you can find one, it will likely cost you an arm and a leg.

And do nothing very useful.


Not likely to pick one up unless it was a very good deal. But it does
look impressive!


..... Phil


John
  #23   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 446
Default Oldschool tubes

On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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



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.


Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.
  #24   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 12,364
Default Oldschool tubes

On Friday, 10 November 2017 15:38:55 UTC, John-Del wrote:
On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:


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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


a red dot, useful

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



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.


Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.


I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.


NT
  #26   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,625
Default Oldschool tubes

On Friday, November 10, 2017 at 10:31:35 AM UTC-5, bitrex wrote:

What happens if you put a portable hole inside a portable hole?


That would be a hole in one.

On tube testers - they are very useful for go/no-go decisions, and if capable of testing for shorts and gas, even useful for limited quality tests. But there are very few OTC tube testers capable of matching. I happen to have one of those few - and it requires additional instrumentation to do this.

As to microphonics - yes the meter will jiggle if a badly (repeat *BADLY* microphonic tube is being tested. And yes, I can leave a KT88 on it for an hour and the power-supply will not heat up, so long-term tests are also possible. Hickok 539B.

Peter Wieck
Melrose Park, PA

  #30   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,212
Default Oldschool tubes

On 10/11/17 09:32, Phil Allison wrote:


The AVO looked like a step up from our current 1950s tester...



** If you can find one, it will likely cost you an arm and a leg.


You're not wrong there...
https://www.ebay.co.uk/itm/AVO-VCM163-tube-valve-tester-/112634545228

--

Jeff


  #31   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 446
Default Oldschool tubes

On Friday, November 10, 2017 at 11:04:53 AM UTC-5, Stephen Wolstenholme wrote:
On Fri, 10 Nov 2017 07:44:42 -0800 (PST), wrote:

On Friday, 10 November 2017 15:38:55 UTC, John-Del wrote:
On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:


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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0


a red dot, useful

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


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.

Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.


I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.


I was a TV engineer for nearly ten years. I never saw a valve TV that
didn't use serial heaters.

Steve

--
http://www.npsnn.com


What country? In the U.S., there were half a dozen large manufactures and they all used power transformers in their console and most table models, leaving some off brand consoles, table models and most portables as series string. I would say at least 80 percent of TVs I worked on at the end of the tube era were equipped with parallel filament circuits.

RCA, Zenith, Motorola, Sylvania, Philco, Admiral etc. all used power transformers. RCA, Zenith and others continued this practice even when they switched to solid state.
  #32   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 86
Default Oldschool tubes

John-Del wrote:
On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:
Not exactly a sophisticated piece of test equipment, but lets you eject
bad metal enclosure tubes early:

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

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



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.


Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.



No surprise at all, since I worked in a radio & TV shop at the time.
DIY types would see ads for them, and bug the shop to buy one for them,
even after telling them that it only looked for open filaments.

  #33   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 86
Default Oldschool tubes

bitrex wrote:

For a brief period transformers were cheaper than a set of tubes with
weird custom filament voltages, but that didn't last long.



Zenith, GE and other name brands continued to build high end sets
with power transformers. Some of the later Zenith TVS had a self
resonant CVT that sold for about 1/3 the price of the set.

Their cheap sets were all series filament, with a voltage doubler
for the B+.
  #34   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default Oldschool tubes

On 2017/11/10 12:46 PM, John-Del wrote:
On Friday, November 10, 2017 at 11:04:53 AM UTC-5, Stephen Wolstenholme wrote:
On Fri, 10 Nov 2017 07:44:42 -0800 (PST), wrote:

On Friday, 10 November 2017 15:38:55 UTC, John-Del wrote:
On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

a red dot, useful

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


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.

Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.

I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.


I was a TV engineer for nearly ten years. I never saw a valve TV that
didn't use serial heaters.

Steve

--
http://www.npsnn.com


What country? In the U.S., there were half a dozen large manufactures and they all used power transformers in their console and most table models, leaving some off brand consoles, table models and most portables as series string. I would say at least 80 percent of TVs I worked on at the end of the tube era were equipped with parallel filament circuits.

RCA, Zenith, Motorola, Sylvania, Philco, Admiral etc. all used power transformers. RCA, Zenith and others continued this practice even when they switched to solid state.


1970s several 12" & 16" GE portable tube TVs used series tube wiring. I
service these TVs as they were used in the first coin operated video
game - Computer Space by Nutting Assoc. There was no line isolating
transformer in the TV, Nutting added one in the cabinet to allow the TV
to be safely used as a B&W monitor.

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
  #35   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,249
Default Oldschool tubes

wrote:

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



I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.



** Here in Australia nearly all valve TVs used large mains transformers. The valves used were 6.3v heater types plus 5V HT and 1.4V EHT rectifiers.

One reason would be that TV valves were made locally in the same factories that supplied radio and audio valves which also used transformers - so there was no local manufacture of series heater types.

The few sets that had series strings were imported from the UK or the USA and so were the needed valves. Same goes for the few compactron sets that were sold here.


..... Phil


  #37   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 12,364
Default Oldschool tubes

On Friday, 10 November 2017 18:19:40 UTC, bitrex wrote:
On 11/10/2017 10:44 AM, tabbypurr wrote:


I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.


For a brief period transformers were cheaper than a set of tubes with
weird custom filament voltages, but that didn't last long.


The 1954 TMB272 used parallel valve heaters for an entirely different reason. It was a dual voltage set, 12v & 240v. From either power it had to derive both filament volts and anode volts. It uses the same transformer on both voltages.


NT
  #38   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 12,364
Default Oldschool tubes

On Friday, 10 November 2017 21:01:57 UTC, Michael Terrell wrote:
bitrex wrote:


For a brief period transformers were cheaper than a set of tubes with
weird custom filament voltages, but that didn't last long.



Zenith, GE and other name brands continued to build high end sets
with power transformers. Some of the later Zenith TVS had a self
resonant CVT that sold for about 1/3 the price of the set.

Their cheap sets were all series filament, with a voltage doubler
for the B+.


I remember a late zenith with swinging choke supply. Why they did that I don't know, must have cost more than regulating properly with silicon.


NT
  #39   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 57
Default Oldschool tubes

On Fri, 10 Nov 2017 12:46:21 -0800 (PST), John-Del
wrote:

On Friday, November 10, 2017 at 11:04:53 AM UTC-5, Stephen Wolstenholme wrote:
On Fri, 10 Nov 2017 07:44:42 -0800 (PST), wrote:

On Friday, 10 November 2017 15:38:55 UTC, John-Del wrote:
On Thursday, November 9, 2017 at 5:58:53 PM UTC-5, Michael Terrell wrote:
bitrex wrote:

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

https://www.dropbox.com/s/m5b4ogl4pqn8tu1/IMG_20171109_110954264.jpg?dl=0

a red dot, useful

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


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.

Not sure how they were hyped, but we used them all the time in the 70s to locate an open tube(s) in series sets. We kept one in our road tube caddy; it even used the same "cheater" cord as the TV did. You'd be surprised how many low end TVs used a series string back then and how often a dead TV was an open filament.

I thought almost all valve tvs used series heaters. Mine doesn't but it's an unusual design, Ekco tmb272.


I was a TV engineer for nearly ten years. I never saw a valve TV that
didn't use serial heaters.

Steve

--
http://www.npsnn.com


What country? In the U.S., there were half a dozen large manufactures and they all used power transformers in their console and most table models, leaving some off brand consoles, table models and most portables as series string. I would say at least 80 percent of TVs I worked on at the end of the tube era were equipped with parallel filament circuits.

RCA, Zenith, Motorola, Sylvania, Philco, Admiral etc. all used power transformers. RCA, Zenith and others continued this practice even when they switched to solid state.


Most of the valve TVs I worked on were made in the UK by a few
different manufacturers. None of them used a mains power transformer.
They all used serial heaters with a big green dropper in series. The
first solid state TV I worked on were made by Thorn and they used an
oscillator to supply high frequency transformers.

Steve




--
http://www.npsnn.com

  #40   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 216
Default Oldschool tubes

On 11/10/2017 04:01 PM, Michael A Terrell wrote:
bitrex wrote:

For a brief period transformers were cheaper than a set of tubes with
weird custom filament voltages, but that didn't last long.



¬*¬* Zenith, GE and other name brands continued to build high end sets
with power transformers. Some of the later Zenith TVS had a self
resonant CVT that sold for about 1/3 the price of the set.

¬*¬* Their cheap sets were all series filament, with a voltage doubler
for the B+.


For amusement here's a representative list of some of the _retail_
prices on the parts list for the 1935 Kadette 52 I'm working on:

Tube socket: $0.10
2 gang tuning "condenser": $1.65
5 inch dynamic speaker: $3.50
6-6-6 uF electrolytic can capacitor: $1.35
IF transformers: $1.25
Broadcast/tuning coils: $1.00
Power transformer: $2.35
Cabinet: $5.70



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Replace T 12 tubes with T8 tubes? walter Home Repair 18 April 27th 11 04:02 AM
Radiant tubes in a concrete/mud slab vs mounting the tubes under the sub floor. [email protected] Home Repair 1 June 4th 07 06:37 AM
metal tubes Allan Adler Metalworking 7 September 26th 03 04:30 AM
How to make tapered tubes? Keith Marshall Metalworking 8 August 12th 03 03:39 AM
Scaffold tubes Simon UK diy 7 July 8th 03 10:57 PM


All times are GMT +1. The time now is 01:36 PM.

Powered by vBulletin® Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright ©2004-2023 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"