What to do to my new-to-me oscilloscope? - Page 1
Forum section: electronics / testgear

author: Phoxtane
author_rank: Regular Contributor
timestamp: March 17, 2018, 12:36:27 am
content: I finally grabbed an oscilloscope, and I'm quite excited. It's a Tektronix 2213A from my university's surplus department, and I managed to grab it for 75USD!However, while I'm enjoying the old-school screen and watching the dot race past, I figure there were probably some maintenance items I should look at - but I've no idea what or if anything needs to be done. For starters, it doesn't have a fan, so I know I will probably not need to open it up and dust it out.Ideally I'd like to calibrate to be accurate as well, but I'm not sure how to start with that.How should I begin bringing this scope back to its full capability?

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: March 17, 2018, 02:21:26 am
content: Quote from: MaxFrister on March 17, 2018, 02:00:11 amYes, metrology is the voltnut weirdo corner of eevblog forum."Test equipment" would be more appropriate or "Repair" if the original poster finds something wrong and starts on a fix-it restoration journey. I believe the forum now enables the the thread creator to move the topic with a button, you no longer need to seek the aid of Simon.

author: Old Printer
author_rank: Frequent Contributor
timestamp: March 17, 2018, 03:04:24 am
content: Artek Manuals has both the service and user manuals available as downloadable pdf's for under $10. A worthwhile investment for anybody willing to pop the hood. I got the manuals for my 2225 and 475 from him and they are text searchable and the schematics are very readable. You might search the internet but many of the free scans are not very good and parts of the schematics can be illegible. One of the greatest things about older Tek scopes is the availability of info on them. Tough to say about parts, but the service manual will give you a performance check section, followed by an adjustment section. A full cal level adjustment requires some specialized equipment, but you can tell a lot with just a decent multimeter.

author: Phoxtane
author_rank: Regular Contributor
timestamp: March 17, 2018, 07:39:05 pm
content: I've gone ahead and moved this to the proper forum.

author: tggzzz
author_rank: Super Contributor
timestamp: March 17, 2018, 10:33:26 pm
content: Quote from: Phoxtane on March 17, 2018, 12:36:27 amI hope you enjoy using your scope.Your first task is to RTFM to find out how to use it effectively.Your second task is to understand the different types of probes, where and how to use them.Your third task is to use your scope.Your fourth task is to accurately define what is not working and what is out of spec.Your last task is to fiddle with the internals - based on what you find isrequiredby the fourth task.Fiddling with the internals too soon is likely to give, um, suboptimal results.

author: EE-digger
author_rank: Frequent Contributor
timestamp: March 18, 2018, 12:29:21 am
content: Pretty much what tggzzz said.Understand probes and probing, compensation and the effect of ground leads. It's amazing how many engineers and techs don't understand them fully after years of use.I always look inside whether or not I should. If it's filthy, a safe and easy way to effectively clean it is to hold a vacuum hose near an area and gently agitate the dust and dirt with a natural bristle brush. Avoid high velocity air as you will develop ESD and may cause damage.Some years ago, I bought a 2213A demo from Tek and loved it. One day it would not power up and I discovered that one of the power rails was shorted to ground. The challenge is that there were maybe 50 or so capacitors on that rail. By careful measurement I was able to track it down to 1 bad cap and all was good again. Never had another problem.For general use, you may want to take a look at dc accuracy (which will also cover your low frequency uses). If you can find schematics you can determine if there are any gain or offset adjustments. If not, just keep a mental reminder of errors. For critical amplitude measurements, click the Y knob into variable position (been a long time, I think it can do this ??) and adjust the trace amplitude against a known source. If your calibrator is accurate, use that. If not, build yourself another square wave oscillator with any CMOS, even a CMOS 555, and an adjustable supply voltage for it. An adjustable LDO is good for that.On a 60MHz analog scope, it's difficult to impossible to look at signals with low repetition rates. If you're trying to observe the characteristics (amplitude, shapw, etc.) of a low rep rate signal, if you can force your signal to repeat more often, you will be able to examine it.First scope is up there between first car and first child in excitement level it generates. Our favorite pizza shop is a mile down the road. The owner ran an electronics company in his former life. One week he was cleaning his basement and asked if I wanted some junk. While I chowed down on lunch, he disappeared and actually went home to get the stuff. He returned with a very nice GenRad Digibridge, digital readout and accurate but definitely no frills. The second items was an old Dumont / Fairchild 401 scope. I almost wet my pants. This was my first scope in my late teens, FIFTY years ago ! This ones needs lots of tube help so now is sitting on my shelf instead of his.Sorry for the long-winded story. Enjoy the scope !

author: alsetalokin4017
author_rank: Super Contributor
timestamp: March 18, 2018, 01:57:56 am
content: Tek 2213a is a fine scope for beginner. Beware: there are significant internal differences between 2213aand 2213, so make sure you get the right Service Manual.Further advice:If it ain't broke Don't Fix It !!