Scope probe question

Thread Starter

neanderman

Joined Aug 23, 2022
5
I'm a newbie to scopes, but i
have this HP 10x attenuating probe that isn't wired. I can figure out how to add a wire, but I'm puzzled. The lead entrance has continuity with the probe point. Is this normal and do I just need to insulate the wired end with some heat shrink tubing?

Also, what kind of wire should I use.
2022-08-2322.37.061709124451.jpgI
 

DickCappels

Joined Aug 21, 2008
9,509
That does not look familiar. Are you sure it is a scope probe?
If it is a scope probe the best solution, if available, is to use a cable with characteristics similar to the original cable.
 

Ya’akov

Joined Jan 27, 2019
6,855
That does not look familiar. Are you sure it is a scope probe?
If it is a scope probe the best solution, if available, is to use a cable with characteristics similar to the original cable.
I agree, Dick. It doesn't look like a scope probe. It seems to be a single wire probe for a DMM or something similar.

Here is an HP 10x probe, which aside from the color scheme (the TS' photo does look like an HP product) is quite different.

tempImageYuoixI.jpg
 

rsjsouza

Joined Apr 21, 2014
368
As Dick and Ya'akov have hinted, this does not look like a probe. Do you have better photos that show the model number and the attenuation factor?
To me this looks like just the tip of a disassembled probe that has seen better days. The fact you can probe 0Ω on this piece is not surprising, as the 10:1 attenuation is done in conjunction with the wire and the small RLC circuit inside the probe's BNC plug - the tip alone does not do that.

Since finding the same type of resistive wire required for an attenuating probe might be difficult and the fact there are many very reasonably priced oscilloscope probes available in the regular channels (eBay, AliExpress, Banggood, etc.), I am not sure if it is worth trying to rebuild a probe out of this part.

At any rate, good luck in your projects and welcome to the electronics world!
 

DickCappels

Joined Aug 21, 2008
9,509
I have bought a few knock-offs of 60 MHz Tektronixs probed for use with a 60 MHz scope, and they were inexpensive but lasted a few years and in direct comparison with the original probes I did not see a difference in performance. The only thing to watch out for is the termination capacitance. The probe must be able to frequency compensate its attenuator (screwdriver adjustment) to match the input capacitance of the scope.
 

Thread Starter

neanderman

Joined Aug 23, 2022
5
I have bought a few knock-offs of 60 MHz Tektronixs probed for use with a 60 MHz scope, and they were inexpensive but lasted a few years and in direct comparison with the original probes I did not see a difference in performance.
Thanks for all the input. I'll look for a working probe.
 

dl324

Joined Mar 30, 2015
15,439
I can figure out how to add a wire, but I'm puzzled. The lead entrance has continuity with the probe point. Is this normal and do I just need to insulate the wired end with some heat shrink tubing?

Also, what kind of wire should I use.
It looks like a variation of one of these probes.
1661871168578.png
The dark gray ones are Tektronix. The other is HP.

On the Tek probes, you can see the ground connection on the left where the cable is attached. The wire is coax and the signal conductor is isolated from the grounded parts.

You can't use any type of coax for a scope probe. Tektronix used a kinked resistive wire so they could control the distributed R/C characteristics. HP and others probably employed Tek's idea.
 
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