You could also try to lower the voltages on the Anode and other supply voltages to the ITS-tubes to check if the problem goes away, aim for 230V, 90V and 36V if at all possible without modification - looking at Paul's schematic it seems like they are controlled by zeners so not easily adjustable unless you replace the zeners.
Most Russians that I've talked to say that the ITS1A/B work a lot better at lower voltages (especially the ITS1A), and you should also be sure not to let them draw excess current on the second Anode which happens if the Thyratron in the ITS1A/B is driven improperly, you can of course also limit the current on the other pins by suitable resistors, one resistor per tube that is, and you should also make sure that the control voltage is in the correct range for the ITS1A. Looking at some panels with these from Russian original designs they have incorporated these current limiting resistors just behind the ITS1A/B tubes as well as zeners protecting them from over voltage and sometimes also ordinary diodes to protect them from reverse voltages if the Thyratron fires in an erroneous mode (one set of components per tube that is). I've built a few of the Russian designs with both ITS1A and ITS1B tubes and I've use the lower set of voltages and never had any mishaps. But before that when I experimented myself I could see that the Thyratrons misfired but fortunately I had the electrodes current limited with resistors so they weren't damaged as far as I could see, they behaved normally after turning of the voltages. /Martin On Saturday, 10 August 2019 17:34:22 UTC+2, Bill Notfaded wrote: > > Also... I've got a bunch of B tubes so I might just replace them all... > I'll try the one first and messing with the frequencies. > > Bill > >> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/915e4d71-5399-44b0-83c1-0a07e2016561%40googlegroups.com.
