I got it up and running! I just replaced Q6 which someone had replaced with a BC327-25, but looking at the circuit diagram I couldn't understand how a PNP transistor could work there so I replaced it with a BC547B as I didn't have any BC337 which was used in the other position.
I also repaired the trace where it had been cut close to the right trim potentiometer for the SCR/UJT control, it should connect the wires from the big electrolytic capacitor down to the three half watt resistors (two of which are 10 Ohm resistors). The Nixie voltages (+200V, +197V and +100V) were a little bit high so I had to turn the left trimmer to its leftmost setting to get the lowest output voltage at the 230VAC Mains voltage we have here in Sweden - I guess these will have to be adjusted when the electronics is connected as there is no feedback in the regulation loop, so I might have to adjust the left trimmer again. Adjusting the right trimmer to far to the left is dangerous as the output voltage rise sharply up to the full wave rectified mains voltage and above, so be careful if you do this!! The positive and negative voltages for the ic's is also high without a load so I'll have to see if I can figure out what resistor to load these voltages with so I can see if they will deliver enough current. I've included a new circuit diagram here with the corrected Q6 transistor and some other small corrections I found while checking it myself. /Martin -- 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/e195640a-4812-4360-b97c-7f4ddf2d21b0%40googlegroups.com.
Schematic Design_ SCM Marchant 414 20191021-2229.pdf
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