Actives or passives ?
I'll probably keep an eye out for something like a P6339A or two.
One of these ?
https://www.ebay.com/p/1100242214
Seems expensive but buffered and passive, how does that work ?
LOL, ah sooo, it's really an active probe !
Nope, the probe head and cable are standard passive jobbys, but since the scope input is only 50
and not the usual 1 Meg (to be used with passive probes) *. That points to what "magic" is inside the box - an impedance converter (aka an buffer amplifier) that has 1 Meg input and 50
output impedance, but a (hopefully flat) gain of 1. Now
how you do that for the given bandwith (and with a constant phase delay as well!),
that's where the
magic comes in .
* The cable between probe head and scope is "1Meg impedance" as well btw, which explains why one can't extend it with 50
coax that might
look the same but isn't, most people try at least once and end up scratching their head why it won't work - I know I did