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He3 corona tube + oscillocope

Posted: Wed Jul 30, 2014 5:36 am
by RealBorg
hi there,

I want to test my He3 tube (CHM32) by hooking it up to a power supply limited to 2400V (diode in reverse) and 25µA (10MOhm resistor) and wait for background impulses.

How should I connect the oscilloscope?
Would a simple voltage divider probe be sensitive enough?
Should I connect a capacitor and limit voltage to the oscilloscope with a diode?
Is it better to measure Delta-I by connecting the tube with inductive coupling to the oscilloscope?


Re: He3 corona tube + oscillocope

Posted: Wed Jul 30, 2014 3:18 pm
by Richard Hull
Either method should work, but simple capacitive coupling is hard to beat. Use a .001ufd 3 or 4 kv capacitor hooked to the tube's central wire and connect the scope through that. Of course, use the limiting resistor from the supply to the central wire to limit the current. Bring the supply voltage up slowly until you see pulses. You should put the scope on or near its lowest voltage setting.

I hope your scope is a storage type to catch the first pulse. Once captured you can adjust the scope to display the full pulse. reset to another trigger and capture and keep adjusting the scope until you have a nice pulse on the screen. This will tell you a lot about what kind of pre-amp your will need.

Richard Hull