Recent tests have shown that CATHODE voltage breaks down at ~130V, continually leaking current and progressively dropping voltage, making febiad CATHODE testing impossible.

Thursday, January 23, 2025, 15:18    disconnected cathode wire from TBHT feed through, simply suspended in cage.

voltages are held for ~1min prior to increase. current will be reported after 1min and stable.

100V - 0.000mA

120V - 0.000mA

130V - 0.000mA

140V - 0.000mA

150V - 0.000mA

170V - 0.000mA

200V - 0.000mA

Thursday, January 23, 2025, 15:42

Reattached the CATHODE line to TBHT feedthrough. Removed the 100||100kΩ resistor pair that connects TBHT to HVC.

Same process as before:

100V - 0.000mA

120V - 0.000mA

125V - 0.000mA

130V - 0.000mA

135V - 0.000mA

140V - current limit ---> dropped to 52V

venting chamber to investigate lines.

Thursday, January 23, 2025, 17:05

removed piece of broken ceramic that held the coil terminal

still current leaking, but it's not as immediate or as shorted. more resistive.

__V__mA__

30    0

35    2.4

40    6.1 

45   12.2

50   19.5

55   32

60   gradually ramped up to limited

Thursday, January 23, 2025, 17:10

Disconnected COIL terminal.  Behaviour still similarly bad. Doesn't seem to have improved.