GW Instek GOS-6112 Scope - Page 1
Forum section: electronics / testgear

author: 6of1
author_rank: Contributor
timestamp: February 19, 2017, 12:59:23 am
content: This is a first post for me, did do a search to make sure I didn'tduplicate, but hey, it may be. My apologies if so.Picked up a GW Instek GOS-6112 on fleebay a few days ago,just to dip my toes back into the test gear purchasing market (lastbit of gear I picked up was a DMM 20 or so years ago - but I digress)When I unboxed it, I was greeted with this:Oh well, like Dave says: Don't turn it on. Take it apart!First thing that caught my eye was this:What?! Ahh Delay line, methinks! Sure enough, schematic says:I was quite worried about that bent BNC at first, but no worries - it was just thatthe chasis was bent, I suspect whoever loaded it into the shipping box putsome pressure on it when they packed it (or the shipper put a bit toomuch weight around it -)Here is the Trigger section after straightening the little blighter out:For those into input and relay pornHere is the input section:And finally, the working product (please excuse the photo, I was too lazy to get outthe tripod and take a decent snap)Overall it seems to be a decent little scope, and will do the business for the timebeing until I can get a fixed shop set up again, in a year or so. I whipped up alittle signal gen using an Arduino Uno (yeah, I know) and it worked quite well.It also showed me how messy the square waves from my Ollllld (70s era)Digi Designer actually is (I've had this for a while, why I never bothered checkingit with my last scope, I have no idea)Any way, there it is, any one want to see more, I have taken a few highrez shots.

author: Alfredo.mqi
author_rank: Newbie
timestamp: April 04, 2017, 12:47:42 am
content: Hi I just bought one too it 's looking good for the price but, but I made a huge mistake in my country we use 220v AC and the fuse was in the 110V ac option, so in conclusion I blown out the oscilloscope, I just had seen part of the schematic, in your post, so I was wondering if you have the schematic of this oscilloscope and if you can share it with me.

author: 6of1
author_rank: Contributor
timestamp: April 04, 2017, 01:00:18 am
content: Sure...PM me your email address and I will send it to you as an attachment - it is about 2.2 mb

author: Alfredo.mqi
author_rank: Newbie
timestamp: April 04, 2017, 01:12:09 am
content: Thank you, I am so disappointed of my self 😫😫 so sad, on not paying attention to details.

author: ProBang2
author_rank: Frequent Contributor
timestamp: April 04, 2017, 01:52:02 am
content: Congratulations for your aquisition!The CRT-scope seems to be in a very good condition.I wish you a lot of fun with it.And I am astonished...How (and where) do you get the schematics for a GW Instek scope?I am searching for the schematics of a GOS 623B for many years...

author: 6of1
author_rank: Contributor
timestamp: April 04, 2017, 01:58:20 am
content: Found it on here:https://www.elektrotanya.com/gw_instek_gos_6103_6112_sch.pdf/download.htmlCheers...6of1

author: ProBang2
author_rank: Frequent Contributor
timestamp: April 04, 2017, 03:21:46 am
content: Thank you!Found there the schematics for the GOS 620. Maybe similar enough...

author: Alfredo.mqi
author_rank: Newbie
timestamp: April 06, 2017, 07:34:38 pm
content: After a couple of sad days I finally made it work again. Looks fine and functional.Lucky me only the varistor blown out.Next thing I will do is test some circuits.

author: 6of1
author_rank: Contributor
timestamp: April 07, 2017, 01:14:25 am
content: That MOV has seen better days!Looks like it did its job though...Fortunately it went and not the transformer.I like my Instek, it will do the job until I can put my lab back together(more or less) permanently.Well done, enjoy using it!6of1

author: luiziko014
author_rank: Newbie
timestamp: April 09, 2017, 03:56:14 am
content: Two days ago, I have the same problem with the same varistor with my gos-6112, But i cant test still,Do you test your Oscilloscope later when you change the varistor?

author: luiziko014
author_rank: Newbie
timestamp: April 09, 2017, 04:07:12 am
content: Quote from: Alfredo.mqi on April 06, 2017, 07:34:38 pmTwo days ago, I have the same problem with the same varistor with my gos-6112, But i cant test still,Do you test your Oscilloscope later when you change the varistor?

author: BMack
author_rank: Regular Contributor
timestamp: April 11, 2017, 06:00:42 am
content: Mind if I ask what you guys paid for these? I have one I (sort of) need to sell so I'm a bit curious about the market.

author: 6of1
author_rank: Contributor
timestamp: April 11, 2017, 01:45:27 pm
content: Mine was $80.00 (U.S. Dollars, or about $106.00 Canadian)

author: CharlieEcho
author_rank: Regular Contributor
timestamp: January 29, 2018, 02:19:31 pm
content: If anyone's looking, someone's selling off a bunch of these on eBay currently at $90 USD, and they look pretty clean:https://www.ebay.com/itm/GW-INSTEK-GOS-6112-100MHz-2CH-Oscilloscope/202133623210Not a seller I've bought anything from, but look to have good feedback.

author: someYguy
author_rank: Newbie
timestamp: February 16, 2018, 08:00:19 pm
content: I have two of the GOS-6112 scopes which I have been using for about 6-7 years now and they both still work great. Haven't yet had any problems with them thank goodness. They are great workhorses. I also have a Tektronix 2235 100mhz and it is nice but I prefer the 6112 due mainly to the cursors. I bought these two on eBay back then and if I recall I paid about $100 each. They have more than paid for themselves over the years and I think that they are a good bang for the used buck.

author: planner29
author_rank: Newbie
timestamp: March 14, 2018, 01:01:57 am
content: Thank you guys for this thread! I really didn't need another scope, but I wanted to try Dave's $50 scope method and so far, I have purchased 3 scopes for less than $150 (including shipping) total! I got the GOS-6112 for $30 offer on eBay + $30 shipping for a total of $60. It was the most expensive scope in the bunch and required about 20 minutes of work (and the schematics link posted here) to get it functioning perfectly!https://www.ebay.com/itm/GW-INSTEK-GOS-6112-100MHz-2CH-Oscilloscope/253452098160?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649I'll keep the GOS-6112 and probably give the Kikusui 5020 ($30 shipped) and the Protek 3502-C ($50 shipped) to students at the university where I work. The Kikusui and Protek required a few hits of contact cleaners and some VR adjustments and they are fully functional too.

author: someYguy
author_rank: Newbie
timestamp: March 21, 2018, 11:33:31 pm
content: Quote from: planner29 on March 14, 2018, 01:01:57 amVery good! What was wrong with your new 6112?. From the description on eBay it sounded kinda serious.

author: planner29
author_rank: Newbie
timestamp: April 03, 2018, 05:31:46 am
content: It wasn't very complex. I should have kept better notes as I recently worked on a half dozen scopes to give to students at the university where I work. I do remember replacing a ribbon cable on the CRT and some passive components that looked suspect. If I have time I can crack it open again and refresh my memory.