The Ebay HP scope repair and teardown thread - Page 1
Forum section: electronics / testgear

author: Iceclaw
author_rank: Contributor
timestamp: July 29, 2015, 03:08:38 am
content: Hi everyone,I'm new around here, as evidenced by my post count, so if this is the wrong place for this thread tell me and I'll move it. That aside, let's move on to the topic of this thread. I recently picked up aHP 1744Aoff of Ebay. The plan is to update this thread if it work or if it doesn't, fix it. I might do a few videos on my youtube channel, but I might not. One thing I will do, however, is write up every time I make significant progress with the repair of the scope. I'll attach photos of the scope when it seems necessary. Until then, I'll look through the manual. (Which is availablehere) It's expected to be here August 4th, so that'll be the next update from me.Until next time,RMEdit: Forgot to close an <a> tag properly.

author: TerraHertz
author_rank: Super Contributor
timestamp: July 29, 2015, 05:36:25 am
content: $2.75 !! Cool, I hope it's easy to fix. Maybe it even works right away, you never know.I have a HP 1743A, serving well as a 'simple stuff' scope.I like the ebay listing "comes with everything shown" and some of the photos are of an 8743B Transmission reflection test unit.Mistake? What mistake?

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: July 29, 2015, 11:09:55 am
content: "The Ebay HP scope repair and teardown thread"Deja vu? There was already a a repair and teardown thread for the 1744A, with pictures:https://www.eevblog.com/forum/repair/hp-1744a-analog-storage-oscilloscope-repair-thread/msg377336/#msg377336Maybe it makes sense adding yours to that thread instead, so that all information can be found in one place instead?

author: Iceclaw
author_rank: Contributor
timestamp: July 29, 2015, 05:08:37 pm
content: Quote from: Wuerstchenhund on July 29, 2015, 11:09:55 amShould i go ahead and add to it before i start posting anything major?

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: July 30, 2015, 06:19:41 am
content: Quote from: Iceclaw on July 29, 2015, 05:08:37 pmPerhaps once you get the scope you could post some infos plus a few pictures there, and then document your findings.

author: Iceclaw
author_rank: Contributor
timestamp: August 05, 2015, 08:04:42 pm
content: Update:Scope is here, and without spoilers, video and pictures will be up tomorrow.

author: Iceclaw
author_rank: Contributor
timestamp: August 07, 2015, 03:51:26 am
content: Quote from: Iceclaw on August 05, 2015, 08:04:42 pmSorry for the wait, the video is taking longer than I thought, so I'll get to posting it at a later date. But onto the scope.The first thought I had when I saw this thing was how yellowed it was, so after a quick clean and some retrobrite it cleaned up nicely. While I still need to clean out and check the internals, I want to wait until I check the calibration a bit more. I suspect that there would be nothing more than a bit of dust due to something on the front that took me a bit to notice. Can you spot it in the pictures? No? Well, the label on the top right says it all. "Hughes aircraft company".Enough with cleaning, let's see if this thing works. Now, I don't have probes and just want to check if I can get a trace. A small amount of wire later and, I'm seeing a nice cal wave. Now, I still haven't checked ext triggering or the big delay dial up in the corner. I'll leave serious calibration until I get some probes. But, I can still check timings and Volts per division. Theyseemfine, but I wont trust what I see until I get actual probes.Anyway,here'sthe photos for this post. The video is still being edited and will be up within the next few days.

author: Vgkid
author_rank: Super Contributor
timestamp: August 07, 2015, 04:01:03 am
content: Looks to be working(we will wait to see how well), I will await any updates.

author: tautech
author_rank: Super Contributor
timestamp: August 07, 2015, 04:45:11 am
content: Quote from: Iceclaw on August 07, 2015, 03:51:26 amGood starting CRO untill you can afford a DSO.If you quote this post you will see how the syntax is used to attach pics.Use Insert Image button.

author: helius
author_rank: Super Contributor
timestamp: August 07, 2015, 05:27:07 am
content: It's a nice scope but has such a small screen.Bonus points to those who know why they made such small screens on scopes like these.

author: Iceclaw
author_rank: Contributor
timestamp: August 07, 2015, 05:29:34 am
content: Quote from: helius on August 07, 2015, 05:27:07 amI'm going to guess because of storage mesh in the crt, but I dont know for sure.

author: helius
author_rank: Super Contributor
timestamp: August 07, 2015, 05:47:08 am
content: Well you're on the right track.This is an almost identical unit to the 1741A, also a storage scope, which has a larger screen (and an additional switch to act as a non-storage scope). By putting both specs side by side you will see something very interesting:1741A1744AStorage speed100 cm/µs1800 cm/µs

author: Iceclaw
author_rank: Contributor
timestamp: August 07, 2015, 07:14:39 pm
content: Update: Probes are here, and the scope iscompletelywithin cal. Triggering and delay works 100%. Not bad for $2.

author: e_sousa
author_rank: Contributor
timestamp: August 08, 2015, 08:04:30 pm
content: Quote from: helius on August 07, 2015, 05:47:08 amLooks like the tek 466 normal scan 150div/µs versus reduced scan 3000div/µs specs.It has a secondary graticule in the center with 0,45cm divisions for the reduced scan mode.

author: rf-loop
author_rank: Super Contributor
timestamp: August 09, 2015, 07:22:43 am
content: Quote from: e_sousa on August 08, 2015, 08:04:30 pmjust for fun one sidenote (and not so seriously)HP 1800cm/µsTEK 1350cm/µsOf course HP can do 4000div/µs if we insert 0.45cm/div grid.This is because also in Tektronix, as in every company, marketing peoples co work with peoples who write specs.After then Tek sales can write 7000 div/µs.. and tell that div is now... now it is very amazing speedwhat looks much better than HP's only 1800cm/µsAnd more, HP speed is full screen and including also variable persistence mode.Reading specifications is...

author: e_sousa
author_rank: Contributor
timestamp: August 09, 2015, 02:50:44 pm
content: Interesting stuff...I figured the different unit for writing speed was for that reason but after the conversion is done the difference is quite significant.Kudos to HP for having been more clear on these specs.