CRO probes, Opinions - best place to buy ?

"kreed"

** Farnell in One have these low cost 250 MHz, 10:1 probes.

Might be better made and last longer - might not.

BTW:

The whole business of CRO probe bandwidth ratings is quite deceitful & full of traps for the unwary.

Eg:

The quoted 250 MHz figure only applies to the 10:1 position - it is very much lower at 1:1.

The source impedance must be 50 ohms to achieve the claimed bandwidth.

The probe has around 15 pF capacitance = 42 ohms at 250 MHz !!

Darn long way from 10 Mohms - what ???

For most RF and wide band measurements, it is far better to use some 50 or

75 ohm coax and a matching terminator at the CRO end of the cable.

Then the load impedance is a fixed, known value and bandwidth is limited only by the CRO itself - NOT by cable reflections and standing wave impedance nulls.

....... Phil

That's a pretty good price for a 250MHz probe. Buy one and try it. I've found the "cheapie" high bandwidth probes to be pretty good in general.

Make sure it comes with the accessory pack with the high speed ground pin attachment, essential for high bandwidth work.

Dave :)