Interesting readout device in an old Tek R5030 scope - Page 1
Forum section: electronics / testgear

author: TerraHertz
author_rank: Super Contributor
timestamp: January 26, 2014, 05:21:42 am
content: I'm starting restoration of an old Tektronix R5030 scope, from around 1969. Nothing special about the scope itself except that it's very pretty, and since I haven't yet found a service manual the project so far involves just cleaning, fitting a mains IEC socket, and other mechanical fixups.But the scope contains an unusual device Tek came up with for readout of the attenuator and timebase settings.The front panel knobs don't have any numbers printed around them. Which is the first time I've ever seen that in an old scope. Nor is there any on-screen readout, unlike the later 7000 series Tek scopes.Instead they have a cute assembly using light bulbs and light fibers, in which the fiber ends are arranged at a front face to form the various numbers and letters they needed.At the moment the scope has a fuse-blowing problem that means this device is not lighting up. Pity. For a little while some of the legends did light up, but by Murphy's law that failed just as I was about to take photos of it. So did the sweep at the same time, and a power supply LV 3A fuse blew. So something died just then, somewhere in the scope. Fixing that will have to wait till I find a schematic.I've found a source for an original manual, but can't afford it (and the postage) atm. If anyone knows of an online pdf, please let me know. Or a cheap paper original, of course!Normally I'd try to restore stuff to original condition, but with this one, since I already had to hack it to add the IEC socket, I'd really like to replace all the incandescent bulbs with LEDs. If at all possible, given that they may be AC driven, and of course from a voltage source, as opposed to via current limiting resistors. Orange or yellow LEDs shouldn't make it look _too_ anachronistic. Ha. Or maybe I'll just go with blue, for a laugh.The scope is complete, I just had the covers and CRT fascia removed when I took the photos.Very interesting to see that Tektronix had this nice printed-anodized aluminum front panel technique perfected so early. I'd thought it was something they developed first with the 7000 series scopes. But apparently not - all the 5000 series scopes had it too. As well as an early form of the plugin module system that worked so well in the 7000 scopes.Incidentally I'm also looking for Tek 5103N-D12 and D13 mainframe scope manuals. Complete, unlike the partial copies at-http://bama.edebris.com/manuals/tek/5103n/Tek 5103N_v6.pdf 8MB-http://elektrotanya.com/tektronix_type-5103n_oscilloscope_instruction_sch.pdf/download.html38MBBoth of which are from the same original scan (eletrotanya copied the BAMA one, but somehow made the filesize 5 times larger while editing out the handwritten note on the title page that mentions it's incomplete.) Both contain only the lower module of the scope, not the upper CRT and deflection amps module.

author: SeanB
author_rank: Super Contributor
timestamp: January 26, 2014, 05:49:51 am
content: If you get it I would be interested in a copy for my one. Nice looking unit there.

author: PA4TIM
author_rank: Super Contributor
timestamp: January 26, 2014, 09:30:23 am
content: That system is also used in the "read out" of the Tek 576 curve tracer. Maybe the manual for that can help you.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 09:56:57 am
content: It's the same as my 5031 ! Here :https://www.eevblog.com/forum/testgear/vintage-tektronix-oscilloscope/Here is a doc, don't know if it's usablehttp://w140.com/tek_r5031.pdf

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 10:09:16 am
content: Many boards seems to be same as on my scope, and pdf should be ok for your scope.Light bulbs are easy to find and I changed almost all. You must be carefull for bulbs on board surrounding optic fibers. If one is broken, I think it will be difficult to repair it.When some bulbs go in short circuit, readout as strange display.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 10:21:51 am
content: I was wondering about differences between 5030 and 5031, and I've found : the storage ! So, the rest of the scope should be the same.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 10:28:58 am
content: Quote from: TerraHertz on January 26, 2014, 05:21:42 amError : 1MHz bandwith but 10uV/div sensibility, and true dual beam !

author: TerraHertz
author_rank: Super Contributor
timestamp: January 26, 2014, 12:42:12 pm
content: Quote from: Lunasix on January 26, 2014, 09:56:57 amThank you! I had looked on the tekwiki site, but only for the 5030. I didn't know there's a 5031 identical except for added storage tube.Incidentally, in that thread you mentioned there is no graticule illumination. Yes there is! See power supply schem, sheet 9. Ganged pot from the readout illumination pot, drives lights via Q772. The bulbs are under a clip-in cover at left of the CRT faceplate.I'm very happy to see the readout bulbs are driven with a variable DC supply. Now if I can find some suitable LEDs with built-in resistors....Ha ha... I had just put it back together, found a big enough plastic bag, wrapped it up, and put it in storage till I found a service manual. Funny how that usually works. The manual is a good quality scan too. Though I still pine for paper.Quote from: Lunasix on January 26, 2014, 10:28:58 amWell yes that's true. Also, I've never seen any other scope use the sweep knob to provide a range of attenuations of an external X signal. As well as the push-turn sweep magnify. That's a really multi-function single knob. It's neat how they can do that because the the knob positions are not numbered on the front panel. So they can be multiple things.Plus there's the dual current probe inputs, and differential or single ended inputs.The 'push-to-beam-find' brightness knobs are nice too.I think I'm going to like this scope.Only thing I can see that will be annoying is the single control for readout & graticule illumination. They should be separately adjustable.Hope I can find some rackmount brackets for it. I can make, but they won't look authentic.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 01:42:27 pm
content: On my 5031, there is no graticule illumination ! No bulb, and no wire to go to hidden bulbs. I've verified many times, and with this photo, there is no doubt.The black foam at left is over holes which could receive bulbs, as on yours.But, if I look at my original paper doc (specifically for this form factor, not for the rackable model), whe can see bulbs. Removed by a previous owner ?

author: c4757p
author_rank: Super Contributor
timestamp: January 26, 2014, 01:46:52 pm
content: Quote from: Lunasix on January 26, 2014, 01:42:27 pmThen why is there a knob for it?

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 01:55:51 pm
content: The knob is for the digital readout. But as I've corrected above, bulbs have possibly been removed, and why if it's true ?Now, I'm sure there was a scale illumination, removed before I get this scope near 1985.

author: SeanB
author_rank: Super Contributor
timestamp: January 26, 2014, 01:59:59 pm
content: Possibly the original owner did not want graticule illumination when using a camera, but wanted the scales to show up on the polaroid film.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 02:16:47 pm
content: Yes, that's exactly what I was thinking while you wrote your answer.Around 1985, I've got 2 same 5031 from a friend, repaired them and kept one, and gave the second to this friend. They ware at same state, I would have restored this scale illumination if one have had this and the second not. So, they have been removed on the 2 scopes.

author: PA4TIM
author_rank: Super Contributor
timestamp: January 26, 2014, 05:38:34 pm
content: I have a HP-122, graticule lighting was an extra option (in 1958) My HP- VNA does not have graticule lighting. But all my Teks do have it. If I remember well the Tek 577 did not have it too.

author: PaulAm
author_rank: Frequent Contributor
timestamp: January 26, 2014, 06:10:53 pm
content: You are correct on the 577. Neither the D1 nor the D2 display units used in the 577 had graticule illumination.

author: Lunasix
author_rank: Regular Contributor
timestamp: January 26, 2014, 07:08:19 pm
content: Graticule illumination appears on schematics and photos coming with the scope. It would have been more simple to disconnect it ! So, not totally clear.