I've seen that probe from Andrew Zonenberg before. He has some really nice other projects also. I think the main issue with that probe is the tip capacitance is actually quite high for a resistive probe, and the bandwidth stops at 2GHz. Not sure why it was necessary to use those Vishay FC0402 resistors. Under 2GHz I don't think a normal 0402 resistor would have been an issue, and they are miles cheaper.
Glad you managed to fix your scope
I've never been good at fixing old oscilloscopes. Last time I took apart my HP 54111D, I managed to achieve nothing but waste time and stress out about killing myself on the CRT.
Nice tuning of that delay haha. Very nice match between the source/measured signal. But yeah, damn dude, that resistive probe is working a charm. Really nice. As always, I think there is a place for active probes above resistive probes. Where you want reduced signal loading, probably sub 2GHz, and for frequency response stability.
My original application was my actively quenched APD as a photon counting module, where I wanted to measure across a 1k ballast resistor restricting current through an APD. A passive probe had way too much capacitance and would have slowed down the response of the signal, a resistive probe would have made the ballast resistor ineffective and probably damaged the APD. An active probe was the only way that I could think of.
On another topic, I was considering a differential version of the probe. I've been playing around in LTSPICE, and I could probably get over 1GHz of bandwidth, with the same 0.7pF tip capacitance, +/- 30V input dynamic range, but I suspect my CMRR wouldn't be great without a bit of work on matching the two inputs closely.