Thanks for the frequency information! You need to increase the value of C5E and C6E to increase the pulse length and increase the bias voltage on R9E & R10E to match values in driving circuits for the GS10C. From the voltage levels shown in your second photo I guess that the pulse voltage is enough (datasheet shows lower pulse voltage for a GS10C), but otherwise R1E & R2E can be adjusted accordingly, hopefully without having to adjust anything else. Page CT-3 here https://www.die-wuestens.de/rd/DEKA.pdf shows the values used for a "selectors" in the right column of the table that ETL recommended. The reset voltage and other cathode voltages shown in the circuit diagram looks to to be ok to me. However the cathode current might be a problem, the simplest way I can see to fix this would need an adapter board where you can use 10 trigger tubes driven by each cathode of the Dekatron to reach enough current. J. B. Dance shows how this can be implemented on page 102 / Fig 4.28 of "Electronic Counting Circuits" for diving a Nixie but that circuit would need some adjustments of course. Or you can use subminiature triodes but that would need more heater power which might not be available from the power supply. Making an adapter board would require the base from a dead GS10C or GC10D or other similar dekatron plus an extra socket for the same dekatron, that might be to much to stuff into the case of the Anita unless there is a possibility of putting the trigger tubes and base into the socket for the GC10D and have wires run to the dekatron and socket which you put somewhere else.
You can experiment with this by just running two wires from the two sides of R2E, from the +495V Anode voltage and GND to a breadboard outside the Anita and then just add the necessary components there and hook up a GS10C there. If you get this to run properly then you will have to experiment with how to hook up the cathodes to deliver enough current. The GS10C with these modifications in place might survive for some time, it all depends on how much current is drawn. I hope this will help you to get a GS10C to work in the Anita. /Martin On Wednesday, 13 June 2018 21:26:52 UTC+2, Roland wrote: > > The Anita runs at 3.6...3.8KHz depending how accurate you tune this > oscillator on V1B. > This is a square wave (more or less). The GS10D can run at 20KHz sine, but > square is quite lower(10KHz). > > A GS10C should be able to run at 4KHz square, that is why I bought such a > tube, just to test... > The GS10C lights up but doesn't move at all... So I thought, let's check > the current trough the original tube. > The GS10D runs on 1,2 or 1,4mA (not sure any more) but that current was > even above spec for a GS10D. > This ETL datasheet book comes from Sumlock, so they should have known > about it :-) > > To be honest, I think Sumlock needed the cathode current to be high enough > to use in the machine. > The P0 to P8 pulses are used to scan the keyboard, P0 and P9 are used > about everywhere in the machine... > That means a quite high cathode current load on the tube. So optimizing > the oscillator would be great > if that makes a GS10C run, but lowering the anode current might be > tricky... > -- 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 [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/f0db32bd-a634-4fcd-8779-74b3b3049ff9%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
