State of the art oscilloscopes - 10 years ago - Page 1
Forum section: electronics / testgear

author: Howardlong
author_rank: Super Contributor
timestamp: December 07, 2014, 09:04:23 am
content: Folks,I came across this online this morning, a review of 20 odd scopes ten years ago.http://david.alfa-romeo.eu/elektro/Elektor_Electronics/2004/Elektor%202004-10.pdfI still have the TDS2024 that I bought around that time, and I did have a scope very similar (certainly in specs) to the the GW Instek GOS620, but ISTR it was rebadged.Pretty much under $1,500 it's all CRT apart from one outlyer that isn't recommended "for serious use".

author: Muttley Snickers
author_rank: Unknown
timestamp: December 07, 2014, 10:43:52 am
content: Not quite 10 years ago, I spent all of my superannuation on a TDS-1002 with the TDS2MEM Compact Flash Module.Not worth their weight in mud these days.But I still love it to bit's, my best investment yet.Muttley

author: kado
author_rank: Regular Contributor
timestamp: December 07, 2014, 11:33:35 am
content: Hi, thanks for sharing this link.Beside the Oscilloscope-Test there is a interesting article about a "poor man's (active) probe".Anybody who has built this probe in the past? Is this circuit worth to build and test it or did anybody have another / better solution for homemade active probes?Karsten

author: HighVoltage
author_rank: Super Contributor
timestamp: December 07, 2014, 11:42:46 am
content: 10 year ago, I used the Fluke PM3394B digital / analog combiscope and for some applications I still have them in use today.Thanks for sharing this great article

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 07, 2014, 11:52:56 am
content: Most of those, like all the CRT ones, were hardly state of the art 10 years ago - more like 15-20

author: rs20
author_rank: Super Contributor
timestamp: December 07, 2014, 12:15:02 pm
content: A mini-highlight for me is page 21, the Game Boy Car with two 3.5mm plugs that turns your Game Boy into "a digital scope". An early version of today's crappy mp3-players shoehorned into terrible oscilloscopes.2 channels, Bandwidth 0.1MHz, 1MSa/s. It has FFT!

author: Howardlong
author_rank: Super Contributor
timestamp: December 07, 2014, 12:43:36 pm
content: Quote from: mikeselectricstuff on December 07, 2014, 11:52:56 amAgreed, I presented it more to show the value we enjoy these days, but I couldn't think of a catchy way of saying that.Cheers, Howard

author: EEVblog
author_rank: Unknown
timestamp: December 07, 2014, 12:46:00 pm
content: Just did a TDS220 video. It will be 20 years old in a few weeks

author: tautech
author_rank: Super Contributor
timestamp: December 07, 2014, 12:51:18 pm
content: Quote from: EEVblog on December 07, 2014, 12:46:00 pmLook forward to that.I was given a "no-go" 210 a few years back, fixed it up and flogged it as I had a 2012B....now thats busted.

author: Howardlong
author_rank: Super Contributor
timestamp: December 07, 2014, 12:59:08 pm
content: Quote from: kado on December 07, 2014, 11:33:35 amI built one Jim Williams style a few months ago, and in fact that was how I found the whole magazine this morining even though I was only after the article about the probe, found scope article. My intention was to build it on a proper PCB instead, as I'm getting the chemicals out for doing a couple of other boards of my own design for something else anyway.The one I built Jim Williams style works but to fudge the front end capacitance I used a chip cap, and the response is hardly flat.

author: coppice
author_rank: Super Contributor
timestamp: December 07, 2014, 01:09:33 pm
content: That list of scopes captures an interesting moment in time. There are two Agilent digital scopes. One has a CRT and one has an LCD.

author: wn1fju
author_rank: Frequent Contributor
timestamp: December 07, 2014, 01:21:34 pm
content: Why stop at 10 years old? In addition to my new Rigol DS1104Z, I also have in my collection (seehttp://emperoroftestequipment.weebly.com/):Fluke PM3390BHP 1980BHP 54112DHP 54615BTek 2213ATek TDS350Tek 7603Tek 7633Tek 7904 (7000 series scopes with about 20 plug-ins)among others. While the waveform update rates are atrocious, the memory is tiny or non-existent, the measurement capabilities are poor, they are large, heavy and power-hungry, all unlike the Rigol, at least they don't lock up sporadically on boot-up, there is no delay jitter and the AC trigger coupling works!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 07, 2014, 02:01:42 pm
content: Quote from: EEVblog on December 07, 2014, 12:46:00 pmI wonder if there would be any interest in a review/opening up of a Tektronix 547, it's probably 50 years old.

author: PlainName
author_rank: Super Contributor
timestamp: December 07, 2014, 06:10:08 pm
content: QuoteGot one sitting on the shelf. Brilliant thing, albeit with limited spec.

author: denelec
author_rank: Regular Contributor
timestamp: December 07, 2014, 06:52:31 pm
content: Quote from: Alex Eisenhut on December 07, 2014, 02:01:42 pmWow! We had exactly this kind of scopes in the labs at University (late '80s). We also had HP tube based signal generators.State of the art material (in 1955).

author: cncjerry
author_rank: Unknown
timestamp: December 07, 2014, 07:18:17 pm
content: Quote from: wn1fju on December 07, 2014, 01:21:34 pmHear! Hear! Man how I agree. Another good example are the Tek TM500 series. With very few exceptions, the modules are easy to repair. The power supplies in particular are pretty clean and functional. I have three racks of them and am able to power separate sections of my projects with current limiting per stage using them.I also love my TDS744a/784a and my more recent TDS3054b. Both old but I see everything I expect to see with them and they don't lock up, jitter, freeze and stutter as some. I also don't need firmware after firmware upgrades.

author: Zero999
author_rank: Super Contributor
timestamp: December 07, 2014, 07:21:05 pm
content: Quote from: Howardlong on December 07, 2014, 09:04:23 amThe quiz is interesting.Anyone get it?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 07, 2014, 08:58:33 pm
content: Quote from: denelec on December 07, 2014, 06:52:31 pmSweet! I was in college in the early '90s and I used my 547 at home. I did the lab assignments with my Amiga and video capture system to insert pictures in the word processor. Not too bad looking on a 24 pin printer either!

author: Howardlong
author_rank: Super Contributor
timestamp: December 07, 2014, 10:02:05 pm
content: Quote from: wn1fju on December 07, 2014, 01:21:34 pmWell that was another hour of my life gone reading that!I'm interested in how you find the HP 1980B? I have one on its way to me that I bought a week or so ago, I always drooled over them when I was in my teens, never had my hands on one though. I can imagine the UI being a bit frustrating what with the single knob. My favourite scope from a UI perspective remains the Tek 24x5 series, it's all there, right in your face, almost no menus apart from for measurements and service, and they are simplicity itself.

author: wn1fju
author_rank: Frequent Contributor
timestamp: December 07, 2014, 11:03:26 pm
content: For Howardlong:Yup, the HP 1980B user interface is a bit annoying with the single knob to adjust all parameters. The tactile feel of the front panel is also a bit anemic. The "buttons," if you can call them that, do make a click sound when pressed. But if I remember, that is produced by a single solenoid that taps something upon any button press. But, the 1980B single knob pales in comparison to my HP 54112D - that one makes me want to throw something through the CRT whenever I fire it up. HP was proud of their 1980B when they designed it as the first microprocessor controlled scope. The four channels are nice, the spec-ed bandwidth is easily exceeded (as are most specs that HP conservatively published). That all being said, at least in the decades long ago, the "theorem" seems to be: Tektronix = oscilloscope, HP = spectrum analyzer. Can't go too wrong by that.

author: Howardlong
author_rank: Super Contributor
timestamp: December 08, 2014, 12:09:12 am
content: Agreed, although I have a Tek TDS460A here that I really struggle to fathom out every time I attempt to use it for more than anything rudimentary: I am still trying to figure out how to get a dual time base sweep on it. I have no real intention of using it for real work, it's become merely an academic exercise.The real scope for real work here is an Agilent 54831D 600MHz which, as you suggest with HP stuff, exceeds that, I measure 528ps rise time and 791MHz 3dB using a Jim Williams pulse generator and RF signal generator. The Tek 2467B I have goes to 551MHz 3dB, but doesn't fair as well on a pulse test, with 990ps being the best I can muster out of it if using the built in measurement system, although if I measure if with the cursors carefully on 500ps/div I measue 780ps.Anyway, I am looking forward to trying out the 1980b when it finally arrives. It has the four channels, digital storage, plot/sequence and key sequence ROM options whatever they do. I'd imagine the digital storage is little more than just that, a screen shot almost, and the single shot sweep in particular looks really a bit limited from the limited information I have.

author: westfw
author_rank: Super Contributor
timestamp: December 08, 2014, 05:09:48 am
content: QuoteI bought a TDS210 back when they were new. It was "OMG - a scope that will fit on my desk instead of needing a lab bench! Sold!"

author: coppice
author_rank: Super Contributor
timestamp: December 08, 2014, 05:46:32 am
content: Quote from: Howardlong on December 08, 2014, 12:09:12 amWhen I first saw a 1980b I thought it was a thing of wonder. I wondered where these guys had got the budget to buy one.The 1980b is really uninteresting when you use it for single shot storage. However, if you have the right plugin it will give you 1GHz bandwidth as a sampling scope, and that was pretty exotic in its day.

author: RJFreeman
author_rank: Regular Contributor
timestamp: December 08, 2014, 05:53:29 am
content: Quote from: westfw on December 08, 2014, 05:09:48 amI purchased a 210 with the FFT/comms module soon after they came out as well, it was compact, relatively affordable (for the day), and very portable (I got the carry bag with it also) and I still use it to this day particularly for field service....

author: Muttley Snickers
author_rank: Unknown
timestamp: December 08, 2014, 07:24:03 am
content: I think that Tektronix should re-release the TDS200-1000 series cases as a promotional lunch box or tool box, I'd buy a couple.Muttley

author: tautech
author_rank: Super Contributor
timestamp: December 08, 2014, 07:30:46 am
content: Quote from: Muttley Snickers on December 08, 2014, 07:24:03 amYep, as Dave will attest, they would keep your lunch or tools dry.

author: Muttley Snickers
author_rank: Unknown
timestamp: December 08, 2014, 07:43:18 am
content: 20 year anniversary promotion,Well sort of were all this compact DSO stuff started from I guess.PS; I never accept version 1 of anything, my girlfriend is version 6.2Muttley

author: rs20
author_rank: Super Contributor
timestamp: December 08, 2014, 09:17:49 am
content: Quote from: Hero999 on December 07, 2014, 07:21:05 pmI'm not well-versed in transistor amplifier layouts (I mean, I know my amps with resistors on both the collector and emitter, gain = -R1/R2 but once we leave that realm I'm out of my comfort zone) so I don't fully grasp the question in the sense that I don't really know which topology is supposed to have a gain of 200. It doesn't seem at all surprising to me that it has a gain of 1800, because I have no particular expectation of what it should be at all. All that aside, SPOILER ALERT,I think it's strange that R4 is connected to the output, not to positive supply. That means that it's parallel to the fixed ~0.7V VBEof T2, and has a more-or-less fixed current running through it. VB, and therefore the output (=VE), can swing wildly with only small changes in IE(T1), since those changes feed in full through to IB(T2). Small changes in input leading to wild swings in output voltage = high gain in my books. The same argument could be made for R3 (in other words, T1 is missing a resistor on its emitter, so by the three-resistor **model** the gain is "infinite"), even though it's not so weird-looking to me intuitively, so, yeah, that's just a handwavy thought.How wrong am I?

author: pomonabill221
author_rank: Frequent Contributor
timestamp: December 08, 2014, 09:23:33 am
content: I have a Tek 7834 analog 400Mhz (in reduced scan mode), with a 7a18 / 7a13a / 7a22 verticals and a 7b92a horiz delaying time base plugins.Bought it about 10 years ago for 400 at a surplus store.Got the service manuals for it and cal'd it.It was the SAME mainframe that I used at Hughes Aircraft in El Segundo (EDSG) in the 80's... I know this because of the pencil marks on some of the knobs, and the coffee mug ring on the top of the cover!Trying to sell it now as I have the Rigol DS1052E (upgraded to the 1100), but of course shipping is ridiculous and nobody wants that old of a scope!A real oldie but goodie!

author: pomonabill221
author_rank: Frequent Contributor
timestamp: December 08, 2014, 09:25:28 am
content: R4 is positive feedback....R3 / R2 / R1 set the bias on T1 and signal is decoupled from T1's base by C1.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 08, 2014, 10:53:40 am
content: Quote from: Hero999 on December 07, 2014, 07:21:05 pmT2 is an emitter-follower. Since R4 sees a constant Veb across it, it acts as a current source to collector of T1.The LF operating point of T1 is set by the R1, C1, R2 LP filter, to bias T1 just into conduction. Then for small signal inputs T1 is acting as a current gain amp, into the very high impedance of the current source of R4. Resulting in very high voltage gain.On the topic of old scopes, I had a lucky ebay buy recently. Not a scope, but an original Tektronix 7000 Series Oscilloscope Product Line Catalog from 1973. 63 Pages, in perfect condition. I think the owner kept it sealed in a bag the last 40 years. A lovely piece of history.Anyway, another item on my 'to scan' list.Here are a few photos.

author: Howardlong
author_rank: Super Contributor
timestamp: December 27, 2014, 08:11:28 pm
content: Quote from: coppice on December 08, 2014, 05:46:32 amWell I finally received the unit just before the xmas break. Wow. As well as a bit of X-Y work before the break, I spent a few hours with "her" today, on real work. Just beautiful.Vid:http://youtu.be/BXOHyjeLAXMI must get out more.