1.5kv probe done.
ok, so what do I need to check now?
Looks pretty good.
The probe part looks a bit long you might want to slip some heatshrink over the end so only 1/2" (12mm), or less, of the tip is expose. That will prevent accidental shorts on other stuff.
The thing to do now is to test the probe on low voltage then gradually move up. If you find a problem don't continue with the higher voltages.
- Measure a 9V battery without the probe, then measure the 9V battery with the probe. You expect 9/1000 = 9mV.
- Measure a 100V supply without the probe, then measure the 100V supply with the probe. You expect 100/1000 = 100mV.
- Measure a 300V supply without the probe, then measure the 300V supply with the probe. You expect 300/1000 = 300mV.
- Measure a 500V supply without the probe, then measure the 500V supply with the probe. You expect 500/1000 = 500mV.
These don't have to be exact voltages the main point is to get some coverage across the range. Your meter provides the reference. For the higher voltages try to measure the actual power supply voltages not things like tube anodes. The reason is, the tube anodes have high value resistors and your meter will give you a false low reading because its 1M input impedance loads the circuit.
Record the points. If you can, record the value of the resistance feeding the supply rail. You will find the probe might be a little off (maybe +/-5% to10%) because of the resistor tolerances and possibly because your existing meter is loading the circuit.
There's a leakage test but I have to see what your meter can do.