Cheap-ish oscilloscope probes? - Page 1
Forum section: electronics / general

author: FenderBender
author_rank: Super Contributor
timestamp: December 20, 2011, 11:56:56 pm
content: If you saw my other post, I just bought a Tek 465M for $80 shipped off eBay. I don't exactly know if it's working, but from the pictures, it was displaying two horizontal lines, so it seems that it's fixable if anything.I don't have probes and I've been looking around and they are expensive as crap. Jeez. $200 for a wire? Sounds almost as silly as the magical wire that audiophools use. Maybe there's something special going on, but...I'm looking for some decent quality probes that are maybe in the area of $25-40. I'm not too sure but it seems that 10X should be good?Any suggestions on some good value probes out there?Thanks.

author: joedevola
author_rank: Contributor
timestamp: December 21, 2011, 12:04:35 am
content: My requirements are fairly modest, I use the scope to trouble shoot audio gear, but I just use the cheap probes listed on epay for about $15 a pair. They work fine and appear to be of the same quality as the probes that came with my Rigol. If you are a professional and using them day in and day out for years for high bandwidth work, then you might justify higher quality probes, but if that was the case you would not have picked up an $80 second hand scopeCheersChris

author: FenderBender
author_rank: Super Contributor
timestamp: December 21, 2011, 12:43:41 am
content: Yeah I guess I'll just get a cheap pair. I've heard so many horror stories, but at at school we use like 30 year old oscilloscopes and dollar store probes, and I've really never had an issue...

author: Unknown
author_rank: Unknown
timestamp: December 21, 2011, 01:37:29 am
content: You should read up on how a passive probe works before you call it just a piece of wire. Just the cable is special lossy coax with a very thin conductor which is made in fairly limited quantities (much less probes in the world than audio cables). The capacitor is also quite critical, dielectric adsorption can seriously mess up your signal. Capacitors may also show a frequency dependence (capacitance changes as function of the frequency). Tek actually bought back their whole hybrid operation after selling it just for the proprietary knowledge on how to make the attenuation hybrid. One convenience feature of the original probes might be an extra pin that indicates the attenuation factor to the scope (if the scope supports this). Cheap probes sometimes also exhibit much more loading at high frequencies.That said, for low frequency use cheap probes are OK as long as they don't die. Original Tek probes are sometimes available for <= $40 on Ebay, although you need to check whether they have the necessary accessories (ground lead, grabber hook).

author: FenderBender
author_rank: Super Contributor
timestamp: December 21, 2011, 01:41:43 am
content: Yes, I know there's circuitry in the little box. I'm just saying: Some of them are REALLY expensive, and I think a modern industrial process wouldn't make them that expensive.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 21, 2011, 02:03:27 am
content: I think if you open up the cheapies,you'll find they use a far from modern industrial process.The important point is that mentioned in passing byalm,in that,it is a quite a small market.Why tool up to make high tech cheap probes,when you could put that investment towards consumer stuff where you do have a huge market?In the meantime,I suggest,buy the cheapies,& when they fail,as they will,replace them.Keep the bits from the broken ones,though,as you may be able to fix the next one that fails.VK6ZGO

author: FenderBender
author_rank: Super Contributor
timestamp: December 21, 2011, 02:13:17 am
content: Thank you. I don't mean to sound ignorant. Yeah my guess on the cheapies would be simple hand-soldered through hole components directly onto the wires and contacts themselves.