New Scope Probes - Page 1
Forum section: electronics / testgear

author: eddy66t6
author_rank: Contributor
timestamp: April 25, 2013, 04:25:08 pm
content: Hey guys, just picked up a new Tektronix TDS 320 for home use there, but... no probes! Any suggestions for a decent brand sub 100 Euros? Pomona 4550B seems to be coming up a bit....Many thanks...

author: casinada
author_rank: Frequent Contributor
timestamp: April 25, 2013, 06:06:39 pm
content: Try to get new old stock of Tektronix probes from e**y.For Low Freq 1xhttp://www.ebay.com/itm/Tektronix-P6101A-34MHz-1x-Passive-Probe-NIB-/380608005221?pt=BI_Oscilloscopes&hash=item589e014465For 100Mhzhttp://www.ebay.com/itm/TEKTRONICS-P6109B-100X10-MHZ-TEST-PROBE-/261204540771?pt=LH_DefaultDomain_0&hash=item3cd100fd63If you're patient you can probably find them for less.

author: nctnico
author_rank: Super Contributor
timestamp: April 25, 2013, 06:19:58 pm
content: Quote from: eddy66t6 on April 25, 2013, 04:25:08 pmGet some Testec probes. They are excellent and cost little money.

author: branadic
author_rank: Super Contributor
timestamp: April 25, 2013, 06:50:19 pm
content: And don't forget to build an active probe for low budget:10:1 DC-500MHzhttp://welecw2000a.sourceforge.net/docs/Hardware/Aktiver_Tastkopf_mit_OPA659.pdf10:1 AC up to 1GHzhttp://www.elektrotanya.com/files/forum/2009/10/e04a036.pdf

author: casinada
author_rank: Frequent Contributor
timestamp: April 26, 2013, 01:11:30 am
content: It is fine to make your own probes or get no brand ones but it is good to at least have one of the real ones to use as a reference. You can have it as a standard to compare the other ones you build yourself.

author: nctnico
author_rank: Super Contributor
timestamp: April 26, 2013, 01:32:35 am
content: Even the 'good' probes are just a needle in a 'pen' attached to a wire. There really is no difference. Probes whether they are cheap or expensive will wear out and need replacing after a few years of use.

author: w2aew
author_rank: Super Contributor
timestamp: April 26, 2013, 01:57:59 am
content: Quote from: nctnico on April 26, 2013, 01:32:35 amI respectfully disagree. High quality 10x probes include carefully designed attenuation and compensation circuitry, special lossy cable, high quality material selection, etc. I have many Tektronix passive probes that are in excess of 20 years old, well used, and still in very usable shape.

author: skipjackrc4
author_rank: Regular Contributor
timestamp: April 26, 2013, 02:44:49 am
content: Quote from: w2aew on April 26, 2013, 01:57:59 amThis. I have some old Tek probes that are still in excellent shape, and they can be dirt cheap on eBay (at least for the 100MHz ones). Even disregarding electrical properties, using a well built probe is much nicer than some cheap thing.

author: eddy66t6
author_rank: Contributor
timestamp: April 26, 2013, 11:53:28 am
content: What a response, a lot to take in! Looking at a few items on the 'bay now, and had never considered making a set, might be a little something for the upcoming holidays!All the same, borrowed a set of probes to check it out, it doesn't seem to be a bad scope for 250 quid!

author: nctnico
author_rank: Super Contributor
timestamp: April 26, 2013, 01:51:57 pm
content: Quote from: skipjackrc4 on April 26, 2013, 02:44:49 amBuying used probes is like buying used underwear. I'm not kidding; who would sell a perfectly good probe or their comfortable underwear? There is so much that can be wrong with a probe that you're always better off buying new ones. As soon as a probe starts to develop intermittant problems I throw the whole thing in the bin after I cut the wire so nobody gets tempted to pick it up and use it again.

author: BravoV
author_rank: Super Contributor
timestamp: April 26, 2013, 02:12:48 pm
content: Quote from: nctnico on April 26, 2013, 01:51:57 pmHow about your kid or whoever inherits when you passed away suddenly leaving them clueless with all your cool gadgets, and all of those stuffs ended with at pennies priced at fleabay ?Yes, I'm a proud owner of old Tek 400 Mhz passive probes, bought used, dirt cheap and still in pristine condition.

author: Unknown
author_rank: Unknown
timestamp: April 26, 2013, 02:39:42 pm
content: Quote from: nctnico on April 26, 2013, 01:51:57 pmYou can apply this same argument to other types of used equipment. How would sell a perfectly good Fluke 87? Who would sell a perfectly good Tek 2465? People that bought new equipment, no longer need it (company downsized, outsourced engineering/production, hobbyists changing priorities), or companies that go bankrupt / people that die.I've bought quite a number of used probes, some of them Tek probes from the eighties, and the only intermittent one was a cheap 100 MHz switchable one that was worth less than $50 when new. A lot can go wrong with a probe during its life, but a lot can also go wrong during design/manufacturing. Designing and manufacturing a passive probe, especially one with a bandwidth exceeding 100 MHz, is a non-trivial task. The tip of those Tek probes does not contain a simple of the shelf SMT resistor/cap, for example. The wire isn't RG-174 either. I would not trust an 'off-brand' probe without careful testing. Brands I would trust are HP/Agilent, Tektronix, Lecroy and PMK.

author: nctnico
author_rank: Super Contributor
timestamp: April 26, 2013, 05:13:59 pm
content: Quote from: alm on April 26, 2013, 02:39:42 pmA piece of equipment usually sits quietly on a bench. A probe is moved constantly, tossed around, maybe run over by an office chair, etc.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 09, 2013, 04:14:45 am
content: I'm about to get a scope on eBay, but they almost all come without probes... So I'm currently debating between some new BK Precision probes (for $50) and Cal Test probes ($40).Funny how the probes cost more than the scope will likely... As for used Tek and other brand probes on eBay, they almost always are out (and go) for just as much... and somehow I've got the feeling that a new BK Precision for $50 will mean more measurement confidence than an ancient Tek for $120...(But feel free to correct me if you think I'm wrong.)

author: JoeyP
author_rank: Frequent Contributor
timestamp: August 09, 2013, 05:12:57 pm
content: Quote from: alm on April 26, 2013, 02:39:42 pm+1 Here to. There is much more to a probe than a pin connected to a wire. I've compared performance and drawn out the circuits of a number of different probes, and can say that the difference is dramatic - both in mechanical integrity and electrical performance. Even the coax cable itself varies considerably from one model to another. The one-hung-low probes tend to be total crap in both dimensions. A well made Agilent or Tek probe can last many years in my experience. Yes, you could buy a worn out probe. You could also buy a worn out <insert anything here>.

author: dfmischler
author_rank: Frequent Contributor
timestamp: August 09, 2013, 06:16:55 pm
content: Quote from: Sigmoid on August 09, 2013, 04:14:45 amI disagree. I have half a dozen or so used Tek probes and they all still seem to meet the original specs (P6109B, P6114B, P6139A, ?). I don't think I paid more than $65 for any of them; some were a lot less. I get the impression that BK Precision simply rebadges whatever gear they can find for a good price.

author: JoeyP
author_rank: Frequent Contributor
timestamp: August 12, 2013, 04:55:34 pm
content: Quote from: dfmischler on August 09, 2013, 06:16:55 pmI've had similar experience. In fact, I view "BK Precision" as an oxymoron. They were ahead of there time decades ago, in that they were offering crappy chinese quality products long before anything was made in china

author: edavid
author_rank: Super Contributor
timestamp: August 12, 2013, 11:08:23 pm
content: It's only a 100MHz scope, and a fairly noisy one (although still nice). It's perfectly OK to get $5 probes from eBay. Or if you must have the readout pin, look for used Tek probes - either the P6109 mentioned, or the P6105.

author: macboy
author_rank: Super Contributor
timestamp: August 13, 2013, 01:49:14 pm
content: Quote from: JoeyP on August 12, 2013, 04:55:34 pmBK does re-badge, it's true. But not just cheap quality Chinese stuff. I have a nice BK DMM that is a re-badged Metrix (France) brand. The BK branded ones did cost significantly less than the OEM Metrix ones. Who knows why. I would buy BK again (after doing research of course).

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 13, 2013, 02:23:41 pm
content: Quote from: macboy on August 13, 2013, 01:49:14 pmLol yea, all the BK crap I've seen on eBay... My favorite is this little while analog portable scope that looks EXACTLY THE SAME regardless of the brand name (Tenma, BK Precision, etc.) XD Also its older brother, the one with the mustard-colored front panel.Anyway, I bought a pair of Chinese probes ($15 for a pair), even if I get better ones they should be good for backup... I'll keep a lookout for brand ones on eBay.(EDIT: The probes turned out to be from Hantek. They look and feel extremely well-made.)