Tektronix 212 oscilloscope restoration  - Page 1
Forum section: electronics / repair

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: August 27, 2015, 06:50:39 pm
content: Restoring a old Tektronix 212 oscilloscope that I won off eBay. Very limited usefulness as Its top bandwidth is 500 kHz and it's maximum vertical sensitivity is 1 mv/ div. Bought it due to it unique size and to mess around with. When I received it, didn't want to power on, only red LED lit, so checks voltages and were OK and then spray contacts and pots with deoxit and pots with fader lube and came to life. Does have issues with is to be expected due to age, but at least for now triggers on both channels, which is a good sign. Will do a full rebuilt and bring back up to specs and rebuilt both battery packs as uses two 5 cells packs. Good thing is they didn't leak all over the place.

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: August 27, 2015, 07:18:58 pm
content: The tear downYou have to remove also this plastic screw for mid CRT support, before removing CRTThe two 5 cell battery packs

author: AF6LJ
author_rank: Unknown
timestamp: August 27, 2015, 09:03:12 pm
content: Very nice; I have a Tek portable scope in the garage I should do a tear down on. it works and is mid to early 1960s vintage.

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: August 28, 2015, 02:33:19 am
content: It back together for now. So now works perfect. Have to wait for some NiCd batteries to show up and then work on the battery packs. Capacitors have good ESR and tested within specs and when though calibration on service manual and was dead on. So no point in changing any components for now. Only issue it had was dirty switches and dead battery pack.

author: Martin.M
author_rank: Frequent Contributor
timestamp: November 07, 2015, 06:55:02 am
content: I cannot see one picture here...The µTek, 200 series have oftenly problems with destroyed boards by acid from bad batteries. So clean the ground board very good.This little scopes was not made for high bandwith. They have other specifications. Look for the sensitivity min. and max. !there was five different types:the 211, a single channel .5mcthe 212, a dual channel .5mcthe 213, a single channel 1mc with onscreen DMM (reading true RMS also, directly from the probe!)the 214, is a 212, but it have a storage CRT, very nicethe 221, a single channel 5mcI need a 211 t complete the little family herepicture: 212, 213, 214, 221, 222 (DSO)greetingsMartin

author: tec5c
author_rank: Frequent Contributor
timestamp: November 07, 2015, 07:54:45 am
content: Quote from: Martin.M on November 07, 2015, 06:55:02 am+1

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 07, 2015, 08:41:06 am
content: Hardly a workaround, but you can click on each picture to view it on Photobucket.Those hand-routed boards look really funky to me, thanks for sharing (and lucky the batteries didn't leak)!

author: Martin.M
author_rank: Frequent Contributor
timestamp: November 07, 2015, 02:11:15 pm
content: when you get a little 212 and you think that is so slowly and not useful today,there is some collecting people who will give 100$ and more for that scope.This scopes was a luxury bad expensive test equipment for engineers with enough money. So they are rare, not oftenly saled.here are the US catalog prices for new Tek 2121974 $7251975 $7551976 $8751977 $10001978 $10801979 $11901980 $13501981 $14751982 $15451983 $17101984 $17751985 $18951986 $20451987 $20951988 (not listed, end)greetingsMartin

author: jh15
author_rank: Frequent Contributor
timestamp: September 08, 2017, 04:57:34 am
content: Bummer about the photobucket ripoff scam.Download anything of value to you, it may fade away on the internet aka Animal Farm book.

author: carl_lab
author_rank: Frequent Contributor
timestamp: September 08, 2017, 06:11:43 am
content: Quote from: jh15 on September 08, 2017, 04:57:34 amOr better upload pics as attached files to the forum, open them in separate windows to get picture links, and finally insert the links as pics to your text.

author: jh15
author_rank: Frequent Contributor
timestamp: September 09, 2017, 05:37:52 am
content: Then Dave will get abducted by aliens. history of pictures kindled at 451 degrees yank, Maybe even probed.

author: JJB
author_rank: Newbie
timestamp: October 29, 2020, 06:59:06 pm
content: Hello.I now own this Tektronix that slept in the closet with friends. I have to change the batteries that are dead.In Europe the current is 220 Vots. I believe there was a specific version for this voltage.How to be sure that this is not the 110 Volt version?Is there a point of information somewhere to avoid toasting it?Thank you.

author: FransW
author_rank: Frequent Contributor
timestamp: October 30, 2020, 10:28:47 am
content: Please re-publish all pictures with the photobucket overlay.They blurr all technical details.Genius @work?Thanks, Frans

author: CaptDon
author_rank: Super Contributor
timestamp: October 30, 2020, 06:29:21 pm
content: BE AWARE, the batteries charge by being capacitively coupledto the A.C. Line!!!! Never plug the scope in without good batteriesin place and be aware of the weird things the scope will do ifplugged in to an improperly polarized socket, the fat blade isground!!!.