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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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21st Jan 2019, 1:42 pm | #1 |
Dekatron
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Oldest oscilloscope with dual timebase?
I was just pondering when the dual timebase oscilloscope was invented.
What is the oldest example known? |
21st Jan 2019, 2:44 pm | #2 |
Nonode
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Re: Oldest oscilloscope with dual timebase?
I'm not sure, GMB, but I've restored a Cossor 3339 Double Beam Oscillograph(Oscilloscope)from 1939 in the past, and a later 1941 339. "Search" will reveal a big thread. I've now passed them onto Mark James. Puckle & Gas Discharge Valve timebases came out in the 1930's if your interested.
Regards, David |
21st Jan 2019, 2:46 pm | #3 |
Octode
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Re: Oldest oscilloscope with dual timebase?
My guess would be the early Tek 500s with plug ins like the 21A & 22A.
Interesting question though. Chris |
21st Jan 2019, 3:56 pm | #4 |
Nonode
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Re: Oldest oscilloscope with dual timebase?
My guess would be the Tektronix 535 from 1954. Useful dual timebases need the trigger/sweep/holdoff state machine which was a Tektronix innovation, so I doubt any other manufacturer produced one before that. The 535 basically set the pattern for the 'modern' oscilloscope, with calibrated time and voltage measurements, flexible triggering and dual timebases.
Chris
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21st Jan 2019, 7:43 pm | #5 |
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Re: Oldest oscilloscope with dual timebase?
Firstly let me say not claiming a first here but hoping for some clarification.
I have a Cossor 1059 which has delayed and expanded timebase settings. It's all valve lots of them so most likely 1950's help would be appreciated Cheers Mike T
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21st Jan 2019, 7:49 pm | #6 |
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Re: Oldest oscilloscope with dual timebase?
A couple of pictures.
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21st Jan 2019, 8:38 pm | #7 | |
Dekatron
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Re: Oldest oscilloscope with dual timebase?
Quote:
In May 1959 they went into performance overdrive. They upgraded the 545 to the 545A, and introduced the 581 and 585 with "approximately" 100MHz bandwidth (they never quite managed that, and they downgraded them to 95MHz). And the bewilderingly complex 555 dual beam scope - essentially two independent oscilloscopes in the same chassis, and two guns and deflection systems in one CRT. They replicated that stunt in the much later 7844, with 400MHz bandwidth. I have a 585A and a 545A, both restored, but have not been switched on in a while. And of course a 7844. Pass the tablets and a glass of water.... Craig |
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21st Jan 2019, 9:05 pm | #8 |
Nonode
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Re: Oldest oscilloscope with dual timebase?
Obviously a good decade later, but Telequipment had a few interesting scopes.
The D55, D55A and D56 all had TWO separate timebases that could work together or separately. ie, one channel at one speed, the other at a different one (True dual beam with separate X and Y plates), or as a typical "delaying timebase". Then there were the D53, D53S and DM53A which had a single timebase, but with a useful trigger delay. That looks a bit like the Cossor shown earlier judging by the front panel. I think their first conventional dual timebase was the D67. Les. |
21st Jan 2019, 9:38 pm | #9 | |
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Re: Oldest oscilloscope with dual timebase?
Quote:
While some other firm might have made an instrument with dual timebases using sync injection, they won't have worked very well. Tek as the first one with a useable dual timebase is a good bet. David
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21st Jan 2019, 11:08 pm | #10 | |
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Re: Oldest oscilloscope with dual timebase?
Quote:
Chris
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22nd Jan 2019, 11:25 am | #11 |
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Re: Oldest oscilloscope with dual timebase?
I think the Cossor 3339 looks like a single timebase double beam scope.
So any prewar dual timebase scopes? I was wondering if dual timebase scopes came about for examining video waveforms, so perhaps starting life in the 30's ? The display of the wartime navigation system GEE is effectively a dual timebase scope I would say, so I was wondering whether this was the first use of that idea or an application of existing technology. |
22nd Jan 2019, 4:52 pm | #12 |
Octode
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Re: Oldest oscilloscope with dual timebase?
Cossor had the 1212 and dual timebase 1220 in the late 50's. Advert in Wireless World. But exactly when I don't know.
It was better than the 545 because you could select which channel you wanted to trigger on, not the composite waveform going to the deflection plates. |
22nd Jan 2019, 7:04 pm | #13 |
Nonode
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Re: Oldest oscilloscope with dual timebase?
Right enough GMB , Cossor 3339's & 339's just had single timebase circuitry, but I just mentioned them as during my initial research several years ago, I read that Cossor were at the forefront of timebase research in the 30's & during the war. The first double beam scope I worked on in the RAF was the Hartley Electromotives 13A from the 1950's, but I cant remember if it had dual timebase circuitry. I don't think so.
Regards, David |
22nd Jan 2019, 7:38 pm | #14 |
Octode
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Re: Oldest oscilloscope with dual timebase?
Oldest Oscilloscope with Dual timebase.
The need to inspect pulse waveforms with slow repetition rates, such as in radar or sonar meant a repetitive timebase (synchronised) was almost useless. The trigger delay was the first attempt to resolve this. Often referred to as a delayed timebase. I suspect the Solartron D300-CT316 (CD568) of 1954 was the first in UK, a RRE design, perhaps from wartime. This trigger delay was used in the Cossor 1035, mark 111 of 1956, (but not the earlier Mark1of 1949). And Solartron CD711-CT414 of 1960. Later in Cossor CDU110 of 1966 and CDU150-CT531 of 1969. EMI/SE Labs used it in the EM102 of 1970. But this trigger delay is awkward to use and once you have used a true dual timebase, you will never want to go back. It seems the dual timebase was first introduced by Tektronix, with the 535/545 in 1954/55. I await further comments from the Tek experts. But rapidly imitated by others. By Hewlett Packard from almost their first scopes; the 140 series from 1965 and 180 series from 1966. Marconi on the 2210 from 1968. From mid 1960's everyone seemed to offer either single TB models, and a more expensive dual timebase version. The trigger delay has disappeared. Tek 543 was single TB, Tek 545 was dual. Solartron CD1212-CT484 was single TB, CD1220 was dual. The Cossor CDU160 or 3100 and Solartron CD1740 of 1972 are both dual TB. The Tek 453 and 454 portable with dual timebase were from 1967. The competing HP1700 series and HP1740-1741 were 1971 and 1975. Picking up David Simpsons point, the Cossor experts on timebase design were OS Puckle (of the Puckle timebase) and BC Fleming-Williams, who developed the transitron, sanatron, phantastron timebases for use in war time radar. Both employed by Cossor. The Hartley 13A is single TB, no trigger delay. A curiously old-fashioned design for 1953. But all these had the option of a triggered timebase as well as synchronised, so you could use it with pulse waveforms. The dear old Metrovick CT52 of 1952 used a Y delay line so that you could see the start of the actual pulse, instead of the next one by the use of trigger delay. Ten years later, all high speed scopes have a Y delay line and we think nothing of it. It looks from the photo posted by MikeT (CobaltBlue) that the Cossor 1059 has the trigger delay system. wme_bill Last edited by WME_bill; 22nd Jan 2019 at 8:07 pm. |
22nd Jan 2019, 9:04 pm | #15 |
Nonode
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Re: Oldest oscilloscope with dual timebase?
Excellent info Bill. Brought back more RAF memories - the CT316, I remember servicing those. Used by the guys in radar bays. Then the HP180A's - replaced the Hartley CT436's(which had in turn replaced the 13A's). CT52's eh - Mark James kindly gave me one about 18months ago - a lovely old wee gem.
Regards, David |
23rd Jan 2019, 7:20 pm | #16 | |
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Re: Oldest oscilloscope with dual timebase?
Quote:
the 555 the 556 the 565 and I think also the 535 was the first Tek with 2 Time Bases, means the 535 no A, in the old brown case with handles from left to right. greeetings Martin
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25th Jan 2019, 4:05 am | #17 |
Dekatron
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Re: Oldest oscilloscope with dual timebase?
Also found this one
http://photobucket.com/gallery/user/...NS5qcGc=/?ref= Mike, you have just solved a long standing mystery. I had one of those 1059's nearly 50 years ago but had forgotten the model no. and couldn't locate an image on line. It lived on a "dinner wagon" which buckled under the strain. I think the 50Mhz calibrator Z-modded the CRT with marker pips, and remind me, what valve type graced the Y amps? Wasn't there a delay-line between all the anodes? I remember being very pleased with myself by finding and repairing multiple faults, and getting it going. Unfortunately my pleasure was short lived because the CRT heater went O/C I managed to weld the break with HV a time or two, but ultimately, it was doomed. I rather naively wrote to Cossor asking for help. Yours is S/N 260, mine was in the 100s. I wonder how many were made and what their target industry was.
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25th Jan 2019, 9:14 am | #18 |
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Re: Oldest oscilloscope with dual timebase?
Yes that photobucket picture is also of my scope.
Pretty certain the Y amps use EL81's I have so far been able to find virtually nothing on this scope. ISTR that the date codes in this one are 1960 Perhaps start a new thread at some point Cheers Mike T
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30th Jan 2019, 6:12 am | #19 | |
Hexode
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Re: Oldest oscilloscope with dual timebase?
Quote:
We used the Tek 545 and 545B for radar service. The "delayed" (ie A TB Runs after Delay) and "triggered delayed" (A TB triggered after Delay) DTB was a godsend. Coupled with Y delay, it made looking at 2uS test pulses 100NM out to be at last feasible and practical. And it even made it possible to observe real returns from an orbiting Flight Check Aircraft at eg 60NM, and to examine Scintillation and other real path effects. Memories ... I used to teach radar, and the Tek 545B. At prac exam time, the students had to set up the CRO to observe the leading edge of say the eighth or ninth pulse from a triggered pulse train, all using triggered delayed TB. And they had to do this with Brightness turned down, so they could not see what they were adjusting. The trigger and delay controls on the Tek 545B were accurate and well defined. But I also wanted to add that one of the joys of using the Tek 545B in radar was that it had quite high beam brightness, as well as the revolutionary dual TBs. . |
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9th Feb 2019, 7:13 pm | #20 | |
Octode
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Re: Oldest oscilloscope with dual timebase?
Quote:
I found pictures of a slightly later 166E sweep delay generator plug-in & it looks very similar to the 1781A (from 1962) plug-in for the 175A scope I have, which wasn't available for long before it got redesigned as the 1781B. There is more from the memories of designer Bob DeVries on the the HP memory project website, see the "Designing plug-ins for the 160A oscilloscope" chapter; http://hpmemoryproject.org/timeline/...rt_03_chapt_10 And the 140A series with 1421A dates back to 1963. David |
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