Tektronix an/usm-488 Accessories needed.  Please Help! - Page 1
Forum section: electronics / testgear

author: thewookie
author_rank: Newbie
timestamp: May 06, 2024, 02:15:39 pm
content: Good day all,Apologies if this is not the right place for this question. Any who, here goes.I am in need of some assistance with people more knowledgeable than myself in electronics test equipment.I am currently in a Tool control position of managing test equipment and tools for my job site. I have this Oscilloscope Tektronix an/usm-488, and it currently has no probes or any other accessories for it.My manager has asked me to locate some probes and and other accessories to replace the missing ones. He said the ones that came with it should suffice. However I have no idea what would have came with it, no part number to go by, therefore I don't know what to replace or even know where to begin.I did go to the Tektronix website and searched for the model number and it appears to me this model is no longer supported any more. Doing a Google search other accessories did come up for this unit, but since I don't know what it came with originally, I don't know what to get.If anyone could help with some advice that would be greatly appreciated. TIA

author: Ugur
author_rank: Regular Contributor
timestamp: May 06, 2024, 02:30:29 pm
content: Hello,This is a 100 Mhz old model analog oscilloscope, so you can buy 2 100 Mhz oscilloscope probes or 150 Mhz from any local dealer to take measurements with this device.You can also find the original accessory list in the attached picture.

author: bdunham7
author_rank: Super Contributor
timestamp: May 06, 2024, 02:31:59 pm
content: There is an information page at TekWiki (an independent website with info on vintage Tektronix products) here:https://w140.com/tekwiki/wiki/2235Your scope is a military version of the Tektronix 2235. The only standard accessories for the Tek 2235 were two probes, p/n P6122. These are still available used on eBay and I think there is even a new one on their now. However, there are many standard 10X or 1X/10X switchable probes available that will work with this scope. My recommendation would be the Probe Master 4905-1, or the 4905-1K if your users want a lot of probe connection options.https://probemaster.com/4900-oscilloscope-probe-basic-kit-150-300-mhz/

author: Ugur
author_rank: Regular Contributor
timestamp: May 06, 2024, 02:33:22 pm
content: Hello,If you want an original part, you can contact the official in Canada.Tektronix, 400 Britannia Road EastMississauga, ON L4Z 1X9Canada877-477-8192

author: thewookie
author_rank: Newbie
timestamp: May 06, 2024, 04:22:12 pm
content: Thanks all for the replies and advise.I will look into your suggestions. However, my company may not like or go for the ebay option. We may not have much of a choice if option are limited.Thanks again, Cheers!

author: thewookie
author_rank: Newbie
timestamp: May 06, 2024, 04:27:50 pm
content: Another question.How do I know if probes I am looking at on a site will fit mine? Are they pretty universal or are they specific to the brand and model?

author: Ian.M
author_rank: Super Contributor
timestamp: May 06, 2024, 04:54:45 pm
content: Probes for older scopes without probe auto-detection are near-universal. They nearly all have a BNC connector and are designed for the scope's 1 Meg input resistance. Obviously you need ones with the same or greater bandwidth to the scope if yoou want to make full use of it. However there is one fly in the ointment. The probe's compensation adjustment range must bracket the scope's input capacitance. Older scopes had a lot more input capacitance than modern ones. Back in the day 1Meg ¦¦ 30pF was typical. Nowadays for current scopes the capacitance is much lower, typically half of that. The manual says your scope's input capacitance is 20pF +/- 2pF.If your beancounters don't like EBAY, suitable probes from mostly the same far east sellers can also be found on Amazon.

author: artag
author_rank: Super Contributor
timestamp: May 06, 2024, 05:02:29 pm
content: Quote from: Ian.M on May 06, 2024, 04:54:45 pmOr electronics distributors such as Digikey. For example this generic probe (selected only because it's first in the search results for 'scope probe' and looks like it matches the requirement Ian.M gave) :https://www.digikey.co.uk/en/products/detail/digilent-inc/460-004/4840870Depending on your users and usage, you might choose to get solid, dependable but fairly expensive probes like the ones from probemaster or generic cheap ones like the above and regard them as disposable. But like any tool, it's best to get good ones and educate the users to treat them well.Note that it's extremely rare to have a sensible use for x1 probes - they have lots of disadvantages as Dave's video shows. So you might be better off getting some that are fixed at x10 rather than x1/x10 switchable, which can get accidentally switched and give you misleading results.Or put some tape over the switch.

author: bdunham7
author_rank: Super Contributor
timestamp: May 06, 2024, 06:01:37 pm
content: Quote from: thewookie on May 06, 2024, 04:27:50 pmThe easiest way is to just ask here with a link to a specific product you are considering. That way those of us familiar with probes can point out any issues. If you want probes that you are sure will work properly in a commercial or professional environment, you should probably stick with good brands and not get cheap generic switchable 1X/10X probes. Probe Master, Cal Test/BK Precision and Testec are all good sources for suitable generic 10X probes and there are others as well.However, if you really want dirt-cheap versions, try yPioneer from AliExpress. These should work:https://www.aliexpress.us/item/3256801867620289.html