Tektronix 222PS scope any good? - Page 1
Forum section: electronics / testgear

author: BillWojo
author_rank: Regular Contributor
timestamp: July 21, 2014, 07:55:05 pm
content: I have a chance to pick one of these up that's supposed to be in good shape for 55.00 bucks. Figure it would make a neat portable scope. Are they any good?ThanksBillWojo

author: Andy Watson
author_rank: Super Contributor
timestamp: July 21, 2014, 08:18:22 pm
content: They are surprisingly "usable" for such a small scope. They have real twiddly knobs too. Performance is respectable for something that was made 20-25 years ago, but bear in mind that things have moved-on considerably since then. Trace width - memory - is very limited by today's standards (512 datapoints max IIRC).Given its age, I would expect the batteries to be shot unless somebody has bodged another set in (the originals are obsolete lead-acid). Also, make sure the channels work properly on all ranges - at the heart of each channel is an unobtainable Tektronix hybrid.Edit: And, the channels are floating. This can be a huge bonus if you require floating measurements; it can also be a pain for low-level stuff - the switching powersupply tends to inject noise into the measurements!

author: elliott
author_rank: Regular Contributor
timestamp: July 21, 2014, 08:48:31 pm
content: It is far more useful than any other portable scope you'll find for $55.They have 100ns glitch capture, which isn't the greatest, but usable for catching intermittent issues. The motor trigger mode is pretty unique.

author: Bryan
author_rank: Frequent Contributor
timestamp: July 21, 2014, 09:09:31 pm
content: Wonder if it is similar to the tear down Davey did on the 216.

author: edavid
author_rank: Super Contributor
timestamp: July 21, 2014, 09:33:53 pm
content: Quote from: BillWojo on July 21, 2014, 07:55:05 pmGrab it... if you don't like it, you could flip it for $150...

author: BillWojo
author_rank: Regular Contributor
timestamp: July 21, 2014, 09:48:28 pm
content: Just got off the phone with the guy. Doesn't have the power adapter. Says it worked fine last time he used it but now I would be buying it untested. Has probes, that's a bonus.BillWojo

author: Andy Watson
author_rank: Super Contributor
timestamp: July 21, 2014, 10:05:18 pm
content: Quote from: BillWojo on July 21, 2014, 09:48:28 pmThe official Tek wall-wart claims to be 18V AC at 880mA.QuoteI'm assuming it is the same as the 222A (same scope without the motor options), the probes are almost integral to the design. i.e. they are not on B.N.C. sockets. The probes do unplug but the plug and socket are non-standard.

author: BillWojo
author_rank: Regular Contributor
timestamp: July 21, 2014, 10:48:21 pm
content: What can I do to power it?

author: Andy Watson
author_rank: Super Contributor
timestamp: July 21, 2014, 11:01:16 pm
content: Quote from: BillWojo on July 21, 2014, 10:48:21 pmThe Operators Manual says:Quote

author: BillWojo
author_rank: Regular Contributor
timestamp: July 22, 2014, 02:13:07 am
content: Would a 18V lithium battery pack from say a Milwaukee drill work? I have M18 battery packs and charger. Would need to rig up a cable and adapter.ThanksBillWojo

author: elliott
author_rank: Regular Contributor
timestamp: July 22, 2014, 02:42:56 am
content: Should work fine.

author: spencerlinn
author_rank: Contributor
timestamp: January 14, 2015, 05:43:23 am
content: Sorry to bump an old thread (as my first post too!!) but believe it or not.. I think I may have just bought the scope you were looking at - like, the same actual unit. Listed on Philly craigslist, missing power adapter. I actually bought a Fluke 189 from the guy and told him I was looking for a small scope for driveway automotive work and he pulled out the 222PS missing the power cable and threw it in even cheaper to help sweeten our not-quite-there deal on the 189. He said it'd been listed a while and he had little interest since it was untested, but I figured for what he offered it for it was worth a gamble. Of course, thanks to this things ridiculously nonspecific input power specs, I just picked up the first power brick I could find and it fired right up and bob's your uncle! I did manage to lose the trace right off the bottom of the screen on the thing though.. this is my first time even using an analog scope with real fiddly knobs, but I suspect I'll get it figured out. It's also in nice shape and it's construction yellow with chunky black rubber grips and stuff… looks like it would've been sold by Nextel back when they were still in business hahaha. What a bobby dazzler!

author: edavid
author_rank: Super Contributor
timestamp: January 14, 2015, 04:12:43 pm
content: Quote from: spencerlinn on January 14, 2015, 05:43:23 amFYI, it's a digital scope.

author: spencerlinn
author_rank: Contributor
timestamp: January 14, 2015, 11:14:48 pm
content: Quote from: edavid on January 14, 2015, 04:12:43 pmedavid you're right! Thanks for pointing that out. I just assumed that since it was old(er) and CRT that it was analog but I realise now that it's digital. I also realised that the triggering was a bit wonky and they just move the trace off the bottom of the screen when there's nothing to trigger on, and you can sort of see the glow from it. I didn't know that's how it was done, none of the LCD digital scopes I've used looked like they did that. I guess it's just due to the CRT display.Oddly, this thing has the original battery in it.. the one which evidently is impossible to find an original replacement. I've seen a few people put NiMH packs and even sealed lead acid by modifying the case, but I might tinker with some lithium rechargeable packs in series and an ebay balancing charger circuit of some kind since lithium ions and the chargers are pretty accessible these days and I like the idea of an intelligent charger since the original lead acid I believe was just fed a constant voltage like a car batt'ry.

author: Martin.M
author_rank: Frequent Contributor
timestamp: January 15, 2015, 06:31:34 am
content: that little Scope is a 10MHz , old DSOinside full smd, very hard to repair and to get spare parts.Related to the slowest scopes you can buy today new it is more slowly, this 10mc are not trustful.But it is a collectors one, I would love to own one for my mini Tek Collection*.If it is in working condition, except the battery, I would give 200$greetingsMartinTek221, Tek 212, Tek213*http://www.wellenkino.de/bilder/mini.jpg

author: spencerlinn
author_rank: Contributor
timestamp: January 16, 2015, 04:25:24 am
content: Honestly the main reason I couldn't pass it up was the condition. I hadn't seen one before this guy showed me this one, but could tell it was an older scope and of course, quite compact for what I presume is an early 90's unit.. I'm guessing, no idea how old it is though. But for a "portable" scope that was surely designed for electricians or automotive work which would be a tough life compared to a bench scope, I couldn't see any signs that it had ever been used - on a bench or under the hood of a car! Not a single scratch I could see, no burn-in at all on the CRT, tilting bail still completely intact, no dirt or wear on the knobs, and the original lead acid battery is in the darn thing, which I've since discovered is rare. I'm sure the lead acid is way past it's prime but still was cool to see it was still in the thing, and one oddball original probe (I think they came with two though.. and isn't easy to find a replacement so might have to try some homebrew probe projects I've found haha). So the only thing it was missing was the power supply, and since it runs on pretty much everything except wood pellets that wasn't a problem that I could see. My uses for it were limited to begin with, I'm not an EE guy by trade so I have to teach myself as I go, and I figured I do enough automotive work for this scope to be useful since I'm certain you could just solder up some alligator clips to a barrel connector and run it from a car batt'ry as well.I have to say the thing I really like about this scope is… definitely the design and look.That Nextel Orange with black rubber bits is just cool to look at, and the quality of the plastics and knobs and such seems very good for an early portable scope where I'm sure every design decision was a compromise.I guess it's not a bad deal then because I think I paid the guy $25 for it! (21.50€) I did have to deal with Philly traffic though so I figure with a pain and suffering tax applied it probably cost me $40.

author: Martin.M
author_rank: Frequent Contributor
timestamp: January 16, 2015, 07:07:17 pm
content: a good deal? You can be happy.In that condition (missing PSU and only one probe) ist still good for paying 200 Dollars for that instrument bec. it is so rare in the second hand market, or the owner call for a money what is tooo high to buy that.You must use original probes, not any other ! The internal resistance ist not the typical 1M like other scopes. read every day the ebay to find one.The day will come. And remember always, when you kill one of the inputs you have a big problem, not a smallTake care for that always.greetingsMartin

author: spencerlinn
author_rank: Contributor
timestamp: January 17, 2015, 06:05:45 am
content: Thanks Martin, for your input! I'll keep an eye out for another original probe since like you said, it's a bit of an odd configuration. You mentioned to be careful not to blow up an input.. is there anything that I should know as far as weaknesses specific to this particular scope? Maybe something I would think is ok for a more "typical" scope but these don't like? Or is it just that they're a pain to replace components if I blow it up ?

author: Martin.M
author_rank: Frequent Contributor
timestamp: January 17, 2015, 11:56:12 am
content: that scope is a very early smd unit, the work in repair is extremly. I think 5 boards and a very lot of wires...the parts are mostly custom, means Tek made. Its very hard to find a spareMuch better to repair are the early analog Mini Tek, they are build with wired parts.And for all Mini Tek: the CRT is obsolete, very hard to find. hat is direct heated 0,55 Volts, shock sensitive, do not put that in postage.greetingsMartin

author: spencerlinn
author_rank: Contributor
timestamp: February 12, 2015, 03:40:27 am
content: So basically… this probably isn't a great scope to use every day.. it's slow, small, limited, and if I blow it up, I'm gonna feel horrible… I need to get a good cookie-cutter, dime-a-dozen Rigol that they make 10 zillion a month and then I won't feel bad if I blow it up!