| John Robertson <spam@flippers.com>: Apr 21 10:28AM -0700 In my field of arcade repairs we run into older jukeboxes - one particular model which uses the 2D21 tube and was from about 1954. I have the spec sheet here: https://www.flippers.com/pdfs/2D21_Thyratron_tube.pdf It would be fun to make a solid state replacement for it as nothing seems to exist. These tubes are still available from several sources, but they get wonky with age. Being able to simply wire in a TRIAC or SCR (with appropriate bits of electronic glue) to remove this tube from the suspect list when servicing this classic Seeburg V200 jukebox would simplify future servicing. I always like to make things easier for the next tech to work on machines that passed through my shop... I should point out that Seeburg only used these 2D21s (three 2D21s used) on their very first control center for their Tormat (200 x magnetic cores) memory and dropped it like a hot potato. There were numerous service bulletins culminating in the factory providing a low cost replacement for the control centers that used 2D21s (three of these) and the replacement used a single 2050 tube and was a very reliable design. Not everyone took advantage of the program and all these replacement were used up long, long ago. 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." |
| bitrex <user@example.net>: Apr 21 01:48PM -0400 On 4/21/2021 1:28 PM, John Robertson wrote: > Not everyone took advantage of the program and all these replacement > were used up long, long ago. > John :-#)# What happens to them as they age? is that with respect to the unused NOS types? I was under the impression that small-signal gas thyratrons were very reliable in service. They're much less temperature sensitive in service than solid state devices, at least. If you blast a relaxation oscillator made with a 2D21 with cold spray it barely drifts. |
| "Peter W." <peterwieck33@gmail.com>: Apr 21 10:49AM -0700 I may have a few of either floating about in my junk boxes. If so, I would be glad to send all that I have to you as I have no discernable use for them. I seem to remember those numbers, Gratis, of course. I will let you know. Peter Wieck Melrose Park, PA |
| John Robertson <spam@flippers.com>: Apr 21 10:53AM -0700 On 2021/04/21 10:48 a.m., bitrex wrote: > reliable in service. They're much less temperature sensitive in service > than solid state devices, at least. If you blast a relaxation oscillator > made with a 2D21 with cold spray it barely drifts. The 2D21 tubes become erratic, sometimes they respond, sometimes they are slow (the solenoid grumbles as it sluggishly engages), and sometimes they just ignore the control signal. Yet these tubes test OK on my mutual conductance tube checker (of course). 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." |
| bitrex <user@example.net>: Apr 21 01:57PM -0400 On 4/21/2021 1:53 PM, John Robertson wrote: > they just ignore the control signal. Yet these tubes test OK on my > mutual conductance tube checker (of course). > John :-#)# Maybe the hydrogen is out-gassing thru the glass over time? |
| bitrex <user@example.net>: Apr 21 02:02PM -0400 On 4/21/2021 1:53 PM, John Robertson wrote: > they just ignore the control signal. Yet these tubes test OK on my > mutual conductance tube checker (of course). > John :-#)# The tube tester can test for conductance from thermionic emission but IDK if it can test for the conductance when the tube is operating in the ionization-cascade mode. |
| John Larkin <jlarkin@highland_atwork_technology.com>: Apr 21 11:14AM -0700 On Wed, 21 Apr 2021 10:28:02 -0700, John Robertson <spam@flippers.com> wrote: >Not everyone took advantage of the program and all these replacement >were used up long, long ago. >John :-#)# Got a schematic? It might be easy. |
| John Larkin <jlarkin@highland_atwork_technology.com>: Apr 21 11:18AM -0700 >The tube tester can test for conductance from thermionic emission but >IDK if it can test for the conductance when the tube is operating in the >ionization-cascade mode. A tube tester may not apply enough voltage or current capability to fire the gas, so would miss a problem with ionization. What's the Gm of a thyratron anyhow? One could build a simple thyratron tester. |
| bitrex <user@example.net>: Apr 21 02:19PM -0400 On 4/21/2021 2:14 PM, John Larkin wrote: >> were used up long, long ago. >> John :-#)# > Got a schematic? It might be easy. The 1954 gear was probably designed to run on old-timey line voltage of ~110 AC. Dialing back the heater voltage on the thyratrons to compensate for higher modern AC supply voltage might extend their life. |
| bitrex <user@example.net>: Apr 21 02:50PM -0400 On 4/21/2021 1:53 PM, John Robertson wrote: > they just ignore the control signal. Yet these tubes test OK on my > mutual conductance tube checker (of course). > John :-#)# Hydrogen diffusion through thin glass within tube-like operating temperatures, where the gas is in thermal equilibrium with the glass and the mean free path is >> glass thickness is dominated by e^(-1/T), so if hydrogen outgassing is causing the erratic behavior whether the tube envelope temperature is run before the "knee" or after may have a lot to do with the expected service life. |
| bitrex <user@example.net>: Apr 21 02:52PM -0400 On 4/21/2021 2:50 PM, bitrex wrote: > Hydrogen diffusion through thin glass within tube-like operating > temperatures, where the gas is in thermal equilibrium with the glass and > the mean free path is >> glass thickness I may have the pac-mans backwards there don't quote me on that. :) |
| bitrex <user@example.net>: Apr 21 03:11PM -0400 On 4/21/2021 2:18 PM, John Larkin wrote: > A tube tester may not apply enough voltage or current capability to > fire the gas, so would miss a problem with ionization. > What's the Gm of a thyratron anyhow? Thyratron anode conductance is grid current-controlled when in the ionization mode, you can read off the parameters from fig 2 of the 2D21 datasheet. For grid 1 voltages between about -1 and -5 volts and Ib between 25 and 200 mA it's vaguely linear at about 50mA per 1 mA. |
| John Robertson <spam@flippers.com>: Apr 21 12:44PM -0700 On 2021/04/21 11:14 a.m., John Larkin wrote: >> were used up long, long ago. >> John :-#)# > Got a schematic? It might be easy. A fairly recent scan (not tidied up) of my files section for the V200 Control Center: https://www.flippers.com/pdfs/Seeburg_V200_Pg_5113-5143_B&W.pdf Relevant schematic is on page 5128 (pg 16 or the PDF). The first control center is the original TSR1-L6, later it shows the replacement control center the TSR3-L6. You can ignore the stepper section, that is the interface to allow booth boxes (called Wall Boxes in the industry) - but it doesn't matter unless one is using those remote selectors... Thanks for looking at this! 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." |
| John Robertson <spam@flippers.com>: Apr 21 12:47PM -0700 On 2021/04/21 11:19 a.m., bitrex wrote: > The 1954 gear was probably designed to run on old-timey line voltage of > ~110 AC. Dialing back the heater voltage on the thyratrons to compensate > for higher modern AC supply voltage might extend their life. This controlled a solenoid at around 24VAC or regulated (0A2 = -150VDC) power supply for the tormat write-in and readout circuits. 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." |
| "ohg...@gmail.com" <ohger1s@gmail.com>: Apr 21 01:05PM -0700 On Wednesday, April 21, 2021 at 1:28:10 PM UTC-4, John Robertson wrote: > the replacement used a single 2050 tube and was a very reliable design. > Not everyone took advantage of the program and all these replacement > were used up long, long ago. Designing a workaround would be easier from the standpoint of seeing exactly how it's wired in a circuit as opposed to making a general sub for that tube. Is there a schematic on-line anywhere? |
| Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat>: Apr 21 05:20PM -0400 On Wed, 21 Apr 2021 12:44:37 -0700, John Robertson <spam@flippers.com> wrote: >Control Center: >https://www.flippers.com/pdfs/Seeburg_V200_Pg_5113-5143_B&W.pdf >Relevant schematic is on page 5128 (pg 16 or the PDF). A thyratron is similar to an SCR, maybe a sensitive-gate type like 2N5064 could be made to work. This one is apparently Xenon-filled. http://www.r-type.org/pdfs/2d21.pdf https://www.mouser.ca/datasheet/2/308/2N5060_D-110409.pdf I don't have the relationships of the thyratron grids in my head though, never designed with one (I once fixed a spot welder that had an enormous lethal-looking high voltage thyratron tube (cap on the top) and a giant step-down transformer to give the kA pulse). Hardly touched vacuum tubes after HS, for that matter. -- Best regards, Spehro Pefhany |
| bitrex <user@example.net>: Apr 21 06:49PM -0400 On 4/21/2021 5:20 PM, Spehro Pefhany wrote: > an enormous lethal-looking high voltage thyratron tube (cap on the > top) and a giant step-down transformer to give the kA pulse). > Hardly touched vacuum tubes after HS, for that matter. Between the forces of good and the Evil Empire they must have made bajillions of these things. Why OP not buy a gross from Russia? Just sitting in their boxes in a dry environment the shelf life might be measured in centuries. <https://www.ebay.com/itm/274314016219?hash=item3fde63b5db:g:T38AAOSwgOpeqBXp> |
| John Robertson <spam@flippers.com>: Apr 21 05:41PM -0700 On 2021/04/21 3:49 p.m., bitrex wrote: > sitting in their boxes in a dry environment the shelf life might be > measured in centuries. > <https://www.ebay.com/itm/274314016219?hash=item3fde63b5db:g:T38AAOSwgOpeqBXp> Where's the fun in that? As I said, I know I can still get new tubes. The problem is the system doesn't work well... 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." |
| "Edward Rawde" <invalid@invalid.invalid>: Apr 21 09:30PM -0400 "John Robertson" <spam@flippers.com> wrote in message news:EKmdnXgYE4CpWx39nZ2dnUU7-Q3NnZ2d@giganews.com... ..... >> <https://www.ebay.com/itm/274314016219?hash=item3fde63b5db:g:T38AAOSwgOpeqBXp> > Where's the fun in that? As I said, I know I can still get new tubes. The > problem is the system doesn't work well... I had a look at the pdf and the schematic looks like a typical work of art from that era. So you could probably get a solid state equivalent designed if you wanted to pay a designer with the necessary experience to do it. I'm not offering but I'd need the hardware in the same room as me to have any chance. |
| DecadentLinuxUserNumeroUno@decadence.org: Apr 22 01:31AM bitrex <user@example.net> wrote in >> Got a schematic? It might be easy. > The 1954 gear was probably designed to run on old-timey line > voltage of ~110 AC. 110 VAC went away at the beginning of the 20th century. By 1950 120 Volts was the standard. The MONIKER remained, but the voltage has been 120 VAC for a VERY long time. > Dialing back the heater voltage on the > thyratrons to compensate for higher modern AC supply voltage might > extend their life. The line voltage was already 120 Volts by then. You need a remedial electrical system / electronics industry history course. Or maybe you would simply develop enough Internet skills to know how to use google properly. |
| Fox's Mercantile <jdangus@att.net>: Apr 21 09:42PM -0500 > 110 VAC went away at the beginning of the 20th century. By 1950 > 120 Volts was the standard. The MONIKER remained, but the voltage > has been 120 VAC for a VERY long time. We go through this over and over again on the antique radio news group. 110, 117, 120 = 120 vac -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| bitrex <user@example.net>: Apr 21 11:11PM -0400 >> extend their life. > The line voltage was already 120 Volts by then. You need a > remedial electrical system / electronics industry history course. But why when there are so many antiques available here to correct me > Or maybe you would simply develop enough Internet skills to know > how to use google properly. Maybe you are so cranky all the time because yous are really easy to manipulate into working for free. |
| bitrex <user@example.net>: Apr 21 11:28PM -0400 On 4/21/2021 10:42 PM, Fox's Mercantile wrote: > We go through this over and over again on the antique radio news > group. > 110, 117, 120 = 120 vac I'm hearing that DLUNU would like to take responsibility for this project and I think he's the best qualified based on his rebuttal. I mean it's in his name. "NumeroUno" |
| DecadentLinuxUserNumeroUno@decadence.org: Apr 22 03:29AM > I'm hearing that DLUNU would like to take responsibility for this > project and I think he's the best qualified based on his rebuttal. I > mean it's in his name. "NumeroUno" In case you missed it, he was backing me up. |
| bitrex <user@example.net>: Apr 21 11:43PM -0400 >> project and I think he's the best qualified based on his rebuttal. I >> mean it's in his name. "NumeroUno" > In case you missed it, he was backing me up. I would hope so! You're team lead, now |
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