The Imax function setup for a linear XT250 supply should work well (fast) to prevent tube screens from getting the Tubelab treatment. 
Oh, for the interface test program, a current graph (during the V ramp) would be nice too. Can put resistors across the power supply then to check current readback and check current limiting.
Oh, for the interface test program, a current graph (during the V ramp) would be nice too. Can put resistors across the power supply then to check current readback and check current limiting.
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Ok, sending the PSU(s) across the ponds (both ways!) is out of question.
What might work is that you could set up a Linux computer (as Raspberry Pi is more than good enough) with remote access (I like https://www.dwservice.net). Then hook up the PSU with an USB/serial adapter cable. I have never done this stuff without having the PSU on my workbench, but it's worth a try.
Let me know if/how you want to proceed. Maybe we should go on by PM to not pollute this thread too much.
What might work is that you could set up a Linux computer (as Raspberry Pi is more than good enough) with remote access (I like https://www.dwservice.net). Then hook up the PSU with an USB/serial adapter cable. I have never done this stuff without having the PSU on my workbench, but it's worth a try.
Let me know if/how you want to proceed. Maybe we should go on by PM to not pollute this thread too much.
So we (valve amateurs) have one sweep tube currently manufactured in the landscape of all those EL 34 - KT 66 - 88 - 90 - 120 etc etc "high mu" "audio" power tubes : good news indeed. Yet where is the stock of some beatiful, old, good "21LG6A ... dirt cheap and with no euphonic distortion to croon over"? Those magnificent television tubes are gone, isn'it?
21LG6 are still cheap here, hopefully they still have stock:
https://vacuumtubes.net/Prices 12A to 29LE3.htm
and I see it on EBAY for more.
But 21LG6 (or other nice bargains like 12GE5, 6GF5, 10JA5, 38HE7, 21HB5, 6CB5, 16/6LU8, 6LR8, 21JV6, 17KV6, most have no plate caps! ) aren't prevalent in Europe.
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re: mbrennwa
The Xantrex interface board manuals have schematics at the back. I notice that 4 voltages are required to operate the XT interface board. But also a bunch of discretes that tell it what power supply it is connected to and front panel signal lights and push-buttons. Not so easy to run it stand-alone. If a cheap Xantrex/Sorensen XT supply could be found in Europe, I could send an interface card over in an envelope to put it in that supply. Just a ribbon cable connection.
https://vacuumtubes.net/Prices 12A to 29LE3.htm
and I see it on EBAY for more.
But 21LG6 (or other nice bargains like 12GE5, 6GF5, 10JA5, 38HE7, 21HB5, 6CB5, 16/6LU8, 6LR8, 21JV6, 17KV6, most have no plate caps! ) aren't prevalent in Europe.
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re: mbrennwa
The Xantrex interface board manuals have schematics at the back. I notice that 4 voltages are required to operate the XT interface board. But also a bunch of discretes that tell it what power supply it is connected to and front panel signal lights and push-buttons. Not so easy to run it stand-alone. If a cheap Xantrex/Sorensen XT supply could be found in Europe, I could send an interface card over in an envelope to put it in that supply. Just a ribbon cable connection.
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It is not just a standard RS232? Awkward. I don't think I want to bother with making an adapter to talk RS232...
The interface card has either standard RS-232 or GPIB connection to the outside world. But the card has two processors on it ( Optical isolation between them, which allows floating the supply ) which determine the ASCII control commands and controls the power supply operation. It was actually quite easy to interface with it just using a dumb terminal program. You just type in the control commands and it responds in text as well. Couldn't be easier really. The processors even do decimal conversions of the binary data for voltage or current. If you want 5.25 Volts, you just type VSET 5.25 (carriage return) or if you want the present output voltage, you just type VOUT? and it returns VOUT xxx.xx Volts. IOUT? will get you the output current. The Command Reference pages give all the commands and responses. You can even calibrate the supply by commands. You can tell it what kind of Foldover response you want if a max limit is exceeded. You can even ask for the model # and serial #. Put delays in .... I think their command set is pretty thorough, but simple operation is easy with just a few commands.
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To message over Intl. phone lines, it will be limited to standard audio band modem speed, like 300 Baud up to a possible 2400 Baud. No Ethernet over the phone line. Modem speeds should be fine anyway for slow power supply control. I can get a modem, RS-232 to RJ-11 phone connector, for less than $20. That's all that's needed on this end, no computer at all. One of us would call, and then I switch on the modem, which is cabled (RS-232 ) to the Xantrex power supply. (it has auto answer mode too ) You will want to read-back V or I etc to verify power supply operations are as commanded. I could also put a scope on the power supply to check operation. Some V ramps or stepping operations say. I can put some load resistors on the supply to get current read-backs. Can try out the XT or XHR supplies then. (same supply commands, different voltage range)
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I had the good fortune to have access to, and to be the worldwide support person for, the Sony Tektronix 370B curve tracer.
Sony Tek was a joint venture between Sony Corporation, and Tektronix incorporated; from the Mid 1960s, to 2000.
The 370B was designed and built in Japan.
I doubt there was ever a more generally capable curve tracer than the 370B.
Cursors was a nice feature, you could easily place a dot on a curve, and rotate the cursor, to get a read out of the dynamic resistance of the curve (like plate resistance, rp),
It was made for solid stage, but with some extra fixtures, could connect it to make it a great vacuum tube curve tracer.
Looking at capacitors and inductors was another capability.
The price was increased a lot, but companies who knew the capability and value, continued purchasing the 370B until production was discontinued.
I have not seen one since 2012.
Sony Tek was a joint venture between Sony Corporation, and Tektronix incorporated; from the Mid 1960s, to 2000.
The 370B was designed and built in Japan.
I doubt there was ever a more generally capable curve tracer than the 370B.
Cursors was a nice feature, you could easily place a dot on a curve, and rotate the cursor, to get a read out of the dynamic resistance of the curve (like plate resistance, rp),
It was made for solid stage, but with some extra fixtures, could connect it to make it a great vacuum tube curve tracer.
Looking at capacitors and inductors was another capability.
The price was increased a lot, but companies who knew the capability and value, continued purchasing the 370B until production was discontinued.
I have not seen one since 2012.
That Grid Step Amplifier adapter I mentioned before is advertised for use with the Sony-Tek 370 also. Gives you a 200 V neg. stepping range then.
Looks to be back in stock on Ebay.
https://www.ebay.com/itm/266781451716
But those TEK 370 type curve tracers are rather expensive on Ebay. I like the Tek 576 since there is no processor in it. You can figure everything out by looking at the schematics. Important if you want to change things.
Looks to be back in stock on Ebay.
https://www.ebay.com/itm/266781451716
But those TEK 370 type curve tracers are rather expensive on Ebay. I like the Tek 576 since there is no processor in it. You can figure everything out by looking at the schematics. Important if you want to change things.
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Goodness, no!
This is 2024, and we both have internet access. I don't think I have seen a modem since the last millennium. International calls would be even more expensive than sending the Xantrex over the pond.
Writing and testing the code/driver for your Xantrex to work with pypsucurvetrace needs a computer connected to the PSU.
My offer stands: I can have a go at it if you set up a Linux computer (like a Raspberry Pi), install a remote service (like dwservice) and hook this up to your Xantrex with a USB/serial cable.
I've found a new flat rate box that will "almost" fit, a board game box, 24" by 11" by 3", for $ 70. Still costs more than buying a power supply, but close. You can just keep it over there. I've got a few supplies. I will have to partially disassemble the 4.5" wide supply to fit the 3", There is also another 12" by 12" by 5" box that might work diagonally.
The E-Tracer and U-tracer designs are undoubtedly the most economical approach, but I already have a TEK 576 working for tubes. Since I already had suitable programmable supplies too (some used with the 576 for screen V and Htr V ) I had been thinking of doing an Extended Basic program Curve Tracer for saving computer data files. Buying programmable supplies from scratch would be quite expensive and slow in operation now, I haven't seen much need for more current capability than the TEK 576 already offers. The Xantrex XHR600V-2 programmable would be over the top for reasonable tubes. Could also use some lower voltage Xantrex supplies, like XHR300-3.5 or XHR150-7.5 or XHR60-18 .... or even XHR7.5-130. Got them all dirt cheap back during the Dot.com crash.
The E-Tracer and U-tracer designs are undoubtedly the most economical approach, but I already have a TEK 576 working for tubes. Since I already had suitable programmable supplies too (some used with the 576 for screen V and Htr V ) I had been thinking of doing an Extended Basic program Curve Tracer for saving computer data files. Buying programmable supplies from scratch would be quite expensive and slow in operation now, I haven't seen much need for more current capability than the TEK 576 already offers. The Xantrex XHR600V-2 programmable would be over the top for reasonable tubes. Could also use some lower voltage Xantrex supplies, like XHR300-3.5 or XHR150-7.5 or XHR60-18 .... or even XHR7.5-130. Got them all dirt cheap back during the Dot.com crash.
PM replied.
Some programmable power supplies may have a software emulation program that can be run on the PC. They put up a screen with V and I readings and status etc. I don't see anything listed at Ametek ( Xantrex lab supplies got merged with Ametek)
National Instruments came up in a Google search for Xantrex, but that will cost $$ plus you likely need their other control software.
Some programmable power supplies may have a software emulation program that can be run on the PC. They put up a screen with V and I readings and status etc. I don't see anything listed at Ametek ( Xantrex lab supplies got merged with Ametek)
National Instruments came up in a Google search for Xantrex, but that will cost $$ plus you likely need their other control software.
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Tektronix CRT for the 576 Curve Tracer:
https://www.ebay.com/itm/145725104841
Tek CRTs are fairly robust unless something hits the faceplate center or neck. I ordered a Tek 577 years ago, and UPS dropped it out of the truck on its front. The CRT flew right out of the unit and that busted the faceplate. That's why I have a 576 and not a 577. Was probably for the best, not complaining.
Here is another remarkable tube that -no one- wants. 6HZ5 (often marked 6JH5/6HZ5/6JD5 ) One of those despised HV Beam Triodes. -EXCEPT-, this tube type works at almost reasonable plate voltages. (the other beam triodes need 1000+ V ) That's because it has NO long/narrow plate "boxlet" between the cathode and plate. The plate support just comes right in to a square corner on the plate. Vacuum distance is minimized. Sometimes 6JD5 or 6JH5 will have this feature too, you have to check the plate picture. 30 Watt or 35 Watt Pdiss. Usually cheap. Curves are nearly the same as some very expensive old triodes which require 100- V grid swing. (this 6HZ5 runs on 7V grid swing)
100V/div Horiz., 20 mA/div Vert., 0.5V grid steps
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