100:1 probe for measuring ripple in a tube amp power supply

[David Hess]

High voltage x100 probes with 10 to 50 megohm input resistance indicating a shunt resistabance to attenuate the DC voltage still exist, at least in theory, but they cost almost $1000 now.  I think Testec used to have a lower cost one but apparently no more.

[vk6zgo]

The only time I've needed a x100 probe was as a "cheap & nasty" substitute for an active probe, back when such devices were prohibitively costly.
They were, of course, conventional ones, but the signal I was looking at required a device with around 100 M input impedance, & was of fairly high level, so it was (just) adequate.

[tautech]

The only time I've needed a x100 probe was as a "cheap & nasty" substitute for an active probe, back when such devices were prohibitively costly.
They were, of course, conventional ones, but the signal I was looking at required a device with around 100 M input impedance, & was of fairly high level, so it was (just) adequate.

Yes, an often overlooked advantage of the 100x probe is the low input capacitance, often well under 5pf.

[floobydust]

This looked reasonable, without the danger of AC-coupling being a problem.

[David Hess]

That is basically the P6009 schematic, shown below.  It takes a little more than the bare essentially to get 100+ MHz performance.