Analog VS Digital Scopes for Glitch Captue

Another Twitter question, a demo of the vast superiority of digital oscilloscopes compared to analog scopes when detecting infrequent glitches. And the importance of Persistence mode in debugging.

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#ElectronicsCreators #Tektronix #oscilloscope

[DrFrank-xjbc]

Once upon a time, there were pure analogue scopes, which had a special cathode-ray tube with analogue persistence, i.e. storage tubes.

[joehubler]

The technique I used on an analog scope back in my day, required a time exposure with a polaroid. yep, I'm that old.

[jenniferwhitewolf]

This is why I have a Tek 7834, Storage scope. It has 'persistence' too, long before Tek, actually Hiro Moriyasu at Tektronix, invented the digital scope. I happen to own Hiro's personal 7704A/P7001 digital scope, and a Tek 7D20 Programable Digitizer for 7000 mainframes. Surrounded by the high end 7000 series mainframes, the 2247A with digital co-processor, is my only pure digital scope, a Siglent 200MHz SDS2202x-E. It mostly gets used in FFT mode being fed from the residual out of an analog Tektronix AA501A distortion analyzer.

[borislipschitz]

I clearly recall older Tektronix scopes (digital ones) having "peak detect" sampling mode. This helped A LOT with spotting glitches.

[caggius]

Takes me back 40 years to when I had to create an almost identical test signal, runt and single bit jitter, to test an early hard disk head amp signal detector board….

[cnxunuo]

Great use case for a Tek 2467B MCP CRT!

[byronwatkins]

Turn up the vertical gain on the analog scope so the brightest horizontal lines are off-screen. This avoids burning the phosphors and makes your eyes slightly more sensitive to the rare events. If you suspect a glitch, this often makes it visible. You can also tweak the focus (and astigmatism if it is equipped). Older analog scopes had less brightness limitation to protect the phosphors and were more useful for this... but required more care to avoid damage.

[BlackEpyon]

My first analog scope (Beckman Industrial 9020) got more "glitches" from dirty pots than anything. Still have it. One day, when I get around to it, I'd like to take it fully apart and give the thing a good cleaning so I can pass it on to somebody else, because it served me well for years, and is a very nice entry-level scope.

[reinerfranke]

The microchannel plate in Tek 2467 and 11300 can show rare events.

[Seiskid]

This is a good video - had no idea my scope had this feature - just checked - it does indeed.

[OneBiOzZ]

Something i would like to see (and have been bitten by) is if you can actually run these scopes for a week while they capture in either infinite persistence or in masked pass/fail mode without crashing/locking up/overheating

[Evergreen]

So now is there a better use case for an analog scope. Something that it will catch or see where a digital scope won't see it?

[delatronics]

Interesting to actually see what jitter looks like.

[milk-it]

Love it. You should write a course on how to use an oscilloscope ;-).

[reedreamer]

Dave - you left out the Siglent SPO (Super Phosphor Oscilloscope) effect! Being a SPO fan-boy I feel a little left out - ; (

[waew]

Dave - you know that you can "swipe" those un-displayed Math waveforms off of the screen.... Just swipe the "badge" off the bottom of the display...

[LutzSchafer]

Yeah but a decent analog tek scope also has a dual time base and holdoff. If setup right you can dim the first time base and then see your runt pulse.

[Retep]

Analog scopes with digital readout like the one in this video have some dead time during which instead of the waveform the text on the screen is drawn. Turning off the readout avoids this dead time. Would it make glitches clearly visible? Probably not.

[proluxelectronics]

I don't get it, a pure analogue scope would not be taking time to do things like on-screen graphics, just the phosphor decay and high speed eyeball refresh rate, (what happened to emoji smily face)

[gerardoromano]

Hi at 2:50 It´s electron not Photons LOL, anyway, great video Dave! Cheers