cheap tek 500MHz passive probes on ebay. can they be used on any scope?

[dbator]

Hello,

Watch out with the P6139A probe.  Unless they've had their cables replaced, they had a whisker- or dendrite-growth problem in the cable that will short out the signal and drive you nuts.  It can be cleared by running some current through the BNC connector but only temporarily.  The only fix is to order a new cable from Tektronix, which I'm not sure you can still do.

Is that a confirmed information? Does that happen often? Is it possible to estimate the probability? Or maybe only counterfeit probes (if there are any on the market) are affected? I wouldn't want to spend about 100 USD for one probe and then throw it out. And I need 4 pcs.
I'm asking because I am about to purchase probes for my scope for which P6139A probes from Tektronix are recommended (capacitance of inputs on my scope is 13 pF). They are obsolete, but still available (second hand). I found some for sale on ebay, but from China which makes me suspicious.

I would purchase new probes from Testec, TT-HF-612 or TT-HF-612RA (with readout attenuator) instead, if they did not cost as twice as the P6139A.
Of course P6139B probes from Tektronix are available as new, but much more expensive than Testec probes, so too expensive for me.

[MarkL]

I have thirteen P6139A probes, nine of them purchased used.  In purchasing the used ones, I encountered two that had internal shorts, possibly from the whisker issue that KE5FX mentions.  The resistance on both indicated the short was at the probe end, so it could have also been the tip cartridge and not the cable; I don't know.  They were returned to the seller for a refund without further investigation.

At any rate, that was 5 years ago, and the nine I kept are still working fine.  The other four I bought new 25 years ago, and they are fine too.

So... I think the P6139A is ok to buy as long as you have a return option.  I would also try to get ones with as many accessories as possible (ground clip, sprung hook, color rings, etc. - see the manual) as genuine accessories can get expensive to buy individually.