On Thursday, November 9, 2017 at 11:14:44 AM UTC-5, 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)Ah, the good old days. Real radios glow in the dark.
Oldschool tubes
Started by ●November 9, 2017
Reply by ●November 9, 20172017-11-09
Reply by ●November 9, 20172017-11-09
On 11/09/2017 08:44 PM, John Larkin wrote:> On Thu, 9 Nov 2017 11:14:39 -0500, bitrex > <bitrex@de.lete.earthlink.net> 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
Reply by ●November 9, 20172017-11-09
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 >> <bitrex@de.lete.earthlink.net> 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 happensActually 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 by ●November 9, 20172017-11-09
John Larkin wrote on 11/9/2017 8:44 PM:> On Thu, 9 Nov 2017 11:14:39 -0500, bitrex > <bitrex@de.lete.earthlink.net> 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
Reply by ●November 10, 20172017-11-10
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 >> <bitrex@de.lete.earthlink.net> 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 happensShorts 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 by ●November 10, 20172017-11-10
bitrex wrote: --------------> > > > 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 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
Reply by ●November 10, 20172017-11-10
On 11/09/2017 11:25 PM, Phil Allison wrote:> bitrex wrote: > > -------------- > > >>> >>> 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 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 > > >Any thoughts on this "We used a PIC!" China special tube tester kit? <https://www.ebay.com/itm/VACUUM-TUBE-TESTER-DIGITAL-LCD-TESTER-KIT-with-4-6-3V-power/162048890376?hash=item25baddd608:g:vRUAAOSwJkJWkbmo>
Reply by ●November 10, 20172017-11-10
In article <6Z6NB.1751$227.328@fx40.iad>, mike.terrell@earthlink.net says...> > 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.I like that idea. Did you have to wear a space-suit in case any vacuum got spilled? Mike.
Reply by ●November 10, 20172017-11-10
Mike Coon wrote: -------------------> > > > > > > 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. > > > I like that idea. Did you have to wear a space-suit in case any vacuum > got spilled? > >** No, but there were were a few mysterious disappearances among regular users. Hence the expression "getting canned" ..... .... Phil
Reply by ●November 10, 20172017-11-10
On 11/10/2017 04:04 AM, Mike Coon wrote:> In article <6Z6NB.1751$227.328@fx40.iad>, mike.terrell@earthlink.net > says... >> >> 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. > > I like that idea. Did you have to wear a space-suit in case any vacuum > got spilled? > > Mike. >I still want my Acme Portable Hole. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net https://hobbs-eo.com
