Re: [neonixie-l] Re: MTX-90 in counting circuit?
Yes, using transistors will do just fine. And you can use the nixie group's favorite, the very common MPSA42, which can withstand 300V. Here are some of my dekatron circuits: http://threeneurons.wordpress.com/dekatron-stuff/ http://threeneurons.wordpress.com/dekatron-stuff/variable-dekatron-spinner-kit/ http://threeneurons.wordpress.com/dekatron-stuff/auxiliary-dekatron-stuff/ http://threeneurons.wordpress.com/nixie-power-supply/nixie-clock-kit-6-digit-with-dekatron-pendulum/ On Wednesday, January 30, 2013 9:37:47 PM UTC-8, Smiffy wrote: On Thursday, January 31, 2013 1:30:50 PM UTC+10:30, threeneurons wrote: Unfortunately, the only trigger that has the proper signal levels to commutate a dekatron properly is the Ericsson GTE175M... Ah, that's a shame - on the basis that the XD18 is to be had plentifully, and at a sensible price. Wonder if it's possible to replace a thermionic triode with a transistor of some description - rather than going the microcontroller route, which I still think seems to be a bit of an overkill, and not really in keeping with the aesthetic I'm looking for. 20V in, 60V down - just an inverter with a gain of 3, isn't it? -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/6WcwwspJeCwJ. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Re: MTX-90 in counting circuit?
You can use a lot of trigger tubes for dekatron coupling, the problem being to bias the trigger electrode correctly - a thing that is much more easy with the GTE175M. There are old East German magazines showing how to use the Z70U and the Z5823 and similar types. The problem is that they don't fit as easily as a coupling stage like the GTE175M does. They don't fit directly for all types of dekatrons as the output voltage change available across the cathode resistor on the dekatron might be too small to fit the trigger voltage necessary for the trigger tube to get a stable triggering point meaning that you will have to use a potentiometer to trim the bias point for each coupling stage. You will usually have to put a negative voltage on the cathode resistor on the dekatron instead of grounding it to get a high enough voltage to reach the necessary trigger voltage change. The Z70U was used as a coupling stage between ZM1070 dekatrons and the Z5823 was used together with Z562S. Since the ZM1070 and Z562S use almost the same voltages as any other dekatron it should be possible to adjust the circuits for them to work properly with any other dekatron as long as the output voltage across the cathode resistor is enough to reach a stable triggering point with the biasing technique. I've heard that Mullard had a coupling stage with the Z70U for their Z504S (identical to the ZM1070) but I have not seen any circuit diagram for it. There is also the possibility of using for instance the EF80 valve as a coupling stage like ETL (Ericsson) did for their GSA10G - have a look at circuit LK201 on page CT-12 here: http://tubehobby.com/datasheets/DEKA.pdf. The EF80 is cheaper than the 12AT7 and it also handles the cut-off for long times better than the 12AT7, the double triode 5963 would be a better choice for long cut-off periods as it was developed for just that purpose in computers. /Martin On Thursday, January 31, 2013 4:00:50 AM UTC+1, threeneurons wrote: Unfortunately, the only trigger that has the proper signal levels to commutate a dekatron properly is the Ericsson GTE175M: http://frank.pocnet.net/sheets/022/g/GTE175M.pdf A dekatron's guides need to see an incoming signal of a very minimum of 60V transition, negative. Its outputs a signal that only goes ~20V, and in the wrong direction. Most triggers need a larger incoming signal. The GTE175M can do the job. All the other ones I've seen can't. In the old days, the interconnecting stage, between dekatrons was usually a vacuum tube triode. The favorite was a 12AT7. Look at figure 4, in this document: http://frank.pocnet.net/sheets/084/7/7155.pdf On Wednesday, January 30, 2013 1:19:28 PM UTC-8, Smiffy wrote: But this thread is rather timely - just yesterday I went back to trying to figure out how to cascade A101 Dekatrons to form a clock/calendar. Whilst I'd figured a simple way to do it, using a tiny microcontroller between each stage (which also makes it easy to set,) barring the initial timing source, I wanted to stay away from silicon if possible. Would something like an XC18 (now that I've located a source,) be suited to this task? (Sufficiently illuminated, that is.) -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/wPiZz2MfaqwJ. For more options, visit https://groups.google.com/groups/opt_out.
RE: [neonixie-l] Re: MTX-90 in counting circuit?
And GDT125T or GTD125M ? As far as I know they are also developed to manage dekatrons. Unfortunately the GDTx' are not very speedy... eric _ From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On Behalf Of threeneurons Sent: donderdag 31 januari 2013 4:01 To: neonixie-l@googlegroups.com Cc: grahame.ma...@googlemail.com Subject: Re: [neonixie-l] Re: MTX-90 in counting circuit? Unfortunately, the only trigger that has the proper signal levels to commutate a dekatron properly is the Ericsson GTE175M: http://frank.pocnet.net/sheets/022/g/GTE175M.pdf A dekatron's guides need to see an incoming signal of a very minimum of 60V transition, negative. Its outputs a signal that only goes ~20V, and in the wrong direction. Most triggers need a larger incoming signal. The GTE175M can do the job. All the other ones I've seen can't. In the old days, the interconnecting stage, between dekatrons was usually a vacuum tube triode. The favorite was a 12AT7. Look at figure 4, in this document: http://frank.pocnet.net/sheets/084/7/7155.pdf On Wednesday, January 30, 2013 1:19:28 PM UTC-8, Smiffy wrote: But this thread is rather timely - just yesterday I went back to trying to figure out how to cascade A101 Dekatrons to form a clock/calendar. Whilst I'd figured a simple way to do it, using a tiny microcontroller between each stage (which also makes it easy to set,) barring the initial timing source, I wanted to stay away from silicon if possible. Would something like an XC18 (now that I've located a source,) be suited to this task? (Sufficiently illuminated, that is.) -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/744HLDyK7w4J. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
RE: [neonixie-l] Re: MTX-90 in counting circuit?
Problem with thermionic tubes are the vulnerability to a kind of cathode poisoning due to lack of current in 'zero time' and the high power consumption. Best should be 'computer grade tubes' like E90CC and E92CC They have specially coated cathodes eric _ From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On Behalf Of Smiffy Sent: donderdag 31 januari 2013 6:38 To: neonixie-l@googlegroups.com Subject: Re: [neonixie-l] Re: MTX-90 in counting circuit? On Thursday, January 31, 2013 1:30:50 PM UTC+10:30, threeneurons wrote: Unfortunately, the only trigger that has the proper signal levels to commutate a dekatron properly is the Ericsson GTE175M... Ah, that's a shame - on the basis that the XD18 is to be had plentifully, and at a sensible price. Wonder if it's possible to replace a thermionic triode with a transistor of some description - rather than going the microcontroller route, which I still think seems to be a bit of an overkill, and not really in keeping with the aesthetic I'm looking for. 20V in, 60V down - just an inverter with a gain of 3, isn't it? -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/6tPXBUsloF8J. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Re: MTX-90 in counting circuit?
I have a brochure from a British valve maker saying that once they solved the interface resistance problem for computer valves they used the same cathodes in all the valves. That seems unlikely for a large valve maker, but maybe this was a smaller outfit. The truth is that large valve makers added silicon to the cathode sleeve mix to make the cathodes activate faster. Faster activation means less time on the activation station, which translates to lower production cost and higher profit. The drawback is that adding silicon was what caused the sleeping sickness in tubes held in cutoff for long periods, so the computer grade tubes cost more to make, as they were made without the silicon. However, money could be saved by using old punches, winders, and so forth, as linearity was not an issue (this is why computer grade tubes are generally not a good bet for audio or other analog/linear use). A smaller outfit, however, may not buy enough cathode sleeve alloy to have two different formulations, and isn't as sensitive to high-volume production, so it could afford to just let all their tubes activate more slowly, and thereby use the the same allow for all their tubes. And naturally, advertise this as an advantage! - John -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Re: MTX-90 in counting circuit?
On 1/31/13 8:30 AM, John Rehwinkel wrote: The drawback is that adding silicon was what caused the sleeping sickness in tubes held in cutoff for long periods, so the computer grade tubes cost more to make, as they were made without the silicon. However, money could be saved by using old punches, winders, and so forth, as linearity was not an issue (this is why computer grade tubes are generally not a good bet for audio or other analog/linear use). The funny thing is that here are some audio files who think that the computer tubes are *better* for audio use, so they have driven up the price of IBM 6211s. -- David Forbes, Tucson AZ -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Re: MTX-90 in counting circuit?
John, thank you for explaining this! I've been looking for a good explanation for quite some time, I've not put much effort into searching but I've been curious what was the difference. -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/UJlZthruOroJ. For more options, visit https://groups.google.com/groups/opt_out.
[neonixie-l] ceramic washers.
It should not be hard at all to make small ceramic washers. I would use a slip casting method. I would start with a plaster of paris sheet poured into a rectangular wood box. The top edges of the wood sides of the box allow you to scrape the poured plaster of paris sheet to have a flat top surface. Plaster of paris is easy to work when it is still damp. Then use a counter bore or make a simple flat bottomed cutter similar to a wood paddle drill. Make a whole lot of flat bottomed dimples (or maybe curved bottom dimples if you want convex washers) Get some porcelain slip and pour it on top of the plaster of paris slab. Squeegee the excess slip off. Let the slip harden to leather hardness. Use a pin or small drill bit to put the hole in the center of each disk of leather hard porcelain slip. Let the slip keep drying. The slip will shrink and pull away from the plaster. After a while you should be able to tip over the slab and have all the washers fall out. A simple table top kiln would be used to fire the porcelain. You could build one for well under $100 worth of parts. Tim Laing BFA in Ceramics -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] ceramic washers.
On 13-01-31 09:53 PM, lai...@wcoil.com wrote: A simple table top kiln would be used to fire the porcelain. You could build one for well under $100 worth of parts. Tim Laing BFA in Ceramics Some places have a local Shop that deals with ceramic crafts, they mayhave a Kiln that they could bake your washers in, or put you in contact with someone who has one they would willing to rent the use of. The shop would also have the right slip -- Charles MacDonald Stittsville Ontario cm...@zeusprune.ca Just Beyond the Fringe http://Charles.MacDonald.org/tubes No Microsoft Products were used in sending this e-mail. -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
[neonixie-l] Selling Some Nixies on E-bay
I thought I would let people know that I am listing some Nixies on E-bay NL841s and NL5440As Look at auction 281056256986. Then look at my other listings. I will probably sell some more than the ones I have listed now. Tim Laing -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Wamco Minitrons
On Tuesday, December 11, 2012 10:40:13 AM UTC-8, bryan wrote: Yeah, I found out that they are still in production for $250 per one item. Yes, you are right, they are ridiculously expensive. I have old 4 KW-105S. ($10 each from eBay) Astonishing. Do you have any idea why on earth someone would still produce these? Whose producing them? -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/b-7JZjlBSw8J. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Selling Some Nixies on E-bay
I thought I would let people know that I am listing some Nixies on E-bay NL841s and NL5440As Look at auction 281056256986. Then look at my other listings. I will probably sell some more than the ones I have listed now. Does the cat come with? - John -- You received this message because you are subscribed to the Google Groups neonixie-l group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: [neonixie-l] Re: MTX-90 in counting circuit?
When the subject came up on TCA a few years back I pointed to the published statement... it was generally agreed there that all companies used improved cathodes. I don't remember whether anyone came up with a black and white statement like the one I had. I'll ask again. A quick look at Kohl [the 1960 edition] reveals that the cathode is extremely complex. Interface resistance affected all tubes but only some circuits were particularly sensitive to it. The problems experienced in wideband scope circuits comes to mind. As the component production methods and controls improved I think that better quality materials came cheaper and were able to be used wider. That effect can be seen in most electronics - eg resistors. The broad statements about computer tubes and interface resistance aren't correct. Quoting from Electron Tube Life Factors, US Army Signal Corps Development Lab, Ft Monmouth, 1959. Cathode Interface Resistance. Cathode interface resistance was measured by Burroughs Corporation on the tubes of the second life test run only for dynamic and static conditions. The tubes of the cutoff conditions were life tested during the second run only and all of them were measured for cathode interface resistance. Burroughs reported that continual calibration of the McNarry bridge for measuring interface resistance was made by artificial impedance networks and by means of stabilized calibrated tubes. Although correlation with other interface resistance tests were not fully satisfactory, the results were consistent and reproducible on the equipment used. The values of interface resistance measured at the end of the 5000-hr life test are listed in Table 12-10 for the three test conditions in the order of increasing silicon content in the cathode sleeves. The pattern of growth of interface resistance is not uniform for all of the tube types. Only for Types JAN-6AG7 and JAN-6AN5 did interface resistance grow to high values for low duty factor and smaller values for high duty factor. The cathode sleeves of these two types had the largest and the smallest amounts of silicon. Those tubes having intermediate percentages of silicon departed from the pattern of the high-silicon tubes and in two cases (Types JAN-5687 and JAN-12AT7) the tubes on cutoff operation had the smallest values of interface resistance. This is the reverse of what has come to be expected. The paragraphs following this discuss the spectrographic examination and the correlation to the actual tubes tested. Some of the data should be assumed to have questionable validity. But a conclusion was still stated... The evidence of this life test and spectrographic analysis does not indicate any conclusive pattern of growth for interface resistance. It is interesting that the results of the JAN-12AT7 surprised them. The pattern of interface resistance growth was unusual in that th etubes on cutoff life test conditions developed the smallest resistance, 2 ohms, during the 5000 hr. The tubes life tested under dynamic conditions, which were equivalent to the cutoff condition in this task, developed 46 ohms of interface resistance. Surprisingly, the tubes life tested under standard MIL conditions developed the highest interface resistance. This was 220 ohms at 5000 hr. The reason for this behavior is not readily apparent. The cathode sleeve material was analyzed by Burroughs Corporation and found to contain a small percentage of silicon, 0.016 percent. This amount is small enough for the cathode to be considered to be made of passive material and not to contribute greatly to the growth of interface resistance. This brings me back to the complexity issue. The mechanisms were not fully understood or characterised. For some tube type results the conclusion was along the lines of eg JAN-7AK7 The silicon content of the cathode sleeves is relatively low at 0.015 percent, and this undoubtedly contributes to the low interface resistance values in all of the tube lots. It is an interesting 173 page book. Interface resistance is a problem, to varying degrees, in dynamic circuits. Manufacturers would have striven to produce the 'perfect' cathode - I want to see more hard data. Obviously costs have to be considered, but manufacturers can't afford to be plagued with erratic unexplained failures and 'modern' production techniques rely on statistical control. The complete short term failure of the very important proximity fuze program is an example that did occur. One manufacturer was able to make reliable filaments [much to the chagrine of the competitors]. However, when that particular single billet of tungsten was exhausted that manufacturer began to suffer the same failures. The not-so-large piece of tungsten made an incredibly large number of filaments; the wire was so fine. John Kaesehagen Australia. jk - Original Message - From: John Rehwinkel jreh...@mac.com To:
