What probes are compatible with an HP/Agilent 54645D?

[Danny R.]

Hello!

I have found this forum recently, and honestly wish I found it sooner, but I'm very excited to explore electronics more seriously and with some help from the very knowledgeable people here. So here's to that!

The first thing I would like some help on is finding passive probes for my new oscilloscope (an HP/Agilent 54645D). I have no idea as to what would be compatible if I were to order new probes, or what people use for those that have the same line, but I'm just trying to get the best "bang for the buck" before I buy secondhand probes that came standard with the scope.

Thanks ahead of time!

[nctnico]

Any standard passive probe will do. Look at the ones from Testec. Stay clear from second hand passive probes; these usually are broken. Do yourself a favour and consider passive probes consumables. Buying such probes second hand is like buying used underwear.

One thing to watch out for is that the probe has enough compensation range. Every oscilloscope has an input capacitance and every passive probe has an adjustment range. For example: if a scope has an input capacitance of 15pf then the probe should have an adjustment range that covers 15pf (from 5pf to 20pf for example).

[tooki]

+1 for testec probes, they’re nice.

FWIW, the Keysight N2140A probes (the ones included with their low end scopes, which is how I’ve used them) are also nice and don’t cost a fortune, about $85 for a two-pack. They’re standard 10:1/1:1 switchable.

I also like the Tektronix TPP0100 (about $60 apiece).

I actually have come to prefer fixed 10:1 probes, like testec TT-LF 212 (about $25 apiece).

[richmit]

I think my 54645D had 15pF input capacitance -- it should be printed on the front of your scope right by the inputs.

I have been using Probemaster 4900 Oscilloscope Probe recently, and have been happy with them.  The compensation range is 10pf-50pf, so they will probably work.

[Danny R.]

Thank you all for the inputs!

I ordered and have received a set of Testec LF-212s. I just "tuned" them and they read well and feel nice, definitely worth the money and looking forward to all the fun to be had with them.

As a note for future reference, I found these probes on Newark for about $35 each. Minimal noise even at the 50 mV division setting with a ~4.5mV error margin (plus or minus). For the signals I'd be reading I think that'll be more than sufficient.