I want to build a high voltage probe to calibrate my 1.5 kV oscilloscope CRT supply voltage.
Will just use this probe once to calibrate the scope so I don’t want to spend $200 on a probe and I mind the safety risks that it may involve.
Have seen several project examples. Some use several small resistors in series with capacitors in between. Others just resistors. Other just one HV resistor.
But before building anything I should consider what fits my multimeter DC Input Impedance which is 7.8 Mohm, right?
So what I need is basically a voltage divider capable of reducing the voltage 10 times. A 70 Mohm probe should achieve the 10x attenuation and bring 1.5 kV down to 150 V if I am not wrong.
I am planning to use one 50 Mohm and one 20 Mohm in series. Both high voltage resistors, rated at 1.5 kV and 1/2 W. Not planning to use any capacitors as well.
Frequency wise will I have any issues considering just this one time CRT calibration?
Is it worth a shot?