Buying a differential probe - Page 1
Forum section: electronics / testgear

author: jgore
author_rank: Contributor
timestamp: February 26, 2014, 06:50:12 am
content: I want to get a differential probe and was hoping that someone could provide direction. I was looking at the HP 1141A. The current ebay prices of these seem to be higher than most of the past sales. Most of the cheaper ones are missing some of the adapters and sell without the 1142A power (although the power modules are plentiful and well under $100)Another one I have looked are those by Pintek - they run $2-300 or so.I don't have any particular application in mind, but is not for really high voltage work or high frequency. I just seem to occasionally have a case where it would seem useful - like audio, or transformers. I can do differential X-Y on my scope, but it ties up 2 channels and also my 1074z can't do further measurements, math or FFT on the X-Y which is a pain.So - any recommendations? Hold out for an HP? Or go with a Pintek? Or something else? My budget is under $400. Am in the US.Thanks

author: kaz911
author_rank: Super Contributor
timestamp: February 26, 2014, 08:38:04 am
content: Quote from: jgore on February 26, 2014, 06:50:12 amI use two of the 1141/1142A combo's - and I'm very happy. Got them for a good price on eBay ($<250) and both came freshly calibrated. But that was a year ago. I use them for CANBUS debugging - and they work absolutely fine - but it is very old "tech" and needs the external power supply/probe interface. So they are space hogs... At some point I'll get some newer battery powered probes for taking on the boat with me.

author: jgore
author_rank: Contributor
timestamp: February 26, 2014, 05:50:49 pm
content: How about a Tektronix A6902, which looks like it isolates the channel from ground, so that you use the probe and its grounding clip to get a differential?

author: MarkL
author_rank: Unknown
timestamp: February 26, 2014, 06:00:35 pm
content: Quote from: kaz911 on February 26, 2014, 08:38:04 am"Old tech" maybe, but some of these differential probes can get quite expensive. External power supplies allow you to move them between different vendor scopes, and also onto different types of equipment like spectrum analyzers.It's less convenient, true, but preserves your probe investment. If cared for, good active probes can be useful through several generations of scope buying. I don't mind the external supplies at all.

author: Kjelt
author_rank: Super Contributor
timestamp: February 26, 2014, 06:17:30 pm
content: Pico technology see farnell but also expensive.

author: kaz911
author_rank: Super Contributor
timestamp: February 27, 2014, 11:39:43 am
content: Quote from: MarkL on February 26, 2014, 06:00:35 pmI'm not planning to get rid of themJust get a portable one for usage "on-site"But I do wish the PSU's was a bit smaller *G* or had longer cables so I could stash them.

author: MarkL
author_rank: Unknown
timestamp: February 27, 2014, 04:01:21 pm
content: Quote from: kaz911 on February 27, 2014, 11:39:43 amRight, I should have paid more attention to what you were saying about battery powered.Whenever someone says they're buying diff probes, my brain immediately jumps to proprietary probe lock-in avoidance.

author: jgore
author_rank: Contributor
timestamp: February 27, 2014, 04:42:44 pm
content: The battery operated ones seem more convenient even at a workbench, have more options for voltage range and attenuation, and they are much newer than a 1141/1142A. I suppose there is a quality difference?

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2014, 12:35:31 am
content: I'm not a fan of battery powered test equipment so I choose to buy one with an adapter. I got it new from Ebay.