Slightly OT: Differences between Tek TDS754A/C/D scopes

Does anyone happen to know the differences between the Tek TDS754A, TDS754C, and TDS754D digital scopes? I finally found a Tek manual that had a table of the specs for 744 vs. 754 vs. 784 vs. 794 and so on, but I've yet to find one that spells out the salient A/C/D changes. (As far as I can tell, the 754 and

784 moved in lock-step between A, C, and D...)

I suspect one of the difference was the change from that funky monochrome CRT

  • R/G/B LCD shutter arrangement Tek had on some of the scopes to a regular color CRT or LCD...

---Joel

Reply to
Joel Koltner
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I saw your post about that on Tekscopes, but the link you posted was screwed up by Yahoogroups. I wish all the guys would move to Usenet, I hate that crappy web interface. Could you re-post the link?

Some of the things I can think of off the top of my head:

  1. The D series would work with an external zip drive.
  2. On the A series, option 1M gave a record length of 130,000 samples, while on the C and D series option 1M was 500,000.
  3. On the C and D series there was an option 2M which increased record length to 8,000,000 samples.
  4. The D series introduced DPO acquisition mode.

From the manual: DPO acquisition mode reduces the dead time between waveform acquisitions that normally occur when digitizing storage oscilloscopes (DSOs) acquire waveforms. This dead-time reduction enables DPO mode to capture and display transient deviations, such as glitches or runt pulses, often missed during longer dead times that accompany normal DSO operation. DPO mode can also display waveform phenomena at an intensity that reflects their rate-of-occurrence. DPO XY and XYZ modes also provide intensity information by accepting continuous, non-triggered data from the input channels. This section describes how to use DPO mode and how it differs from normal acquisition mode. DPO automatically selects record length and sample rate to optimize the displayed image. DPO selects sample rates up to 1 GS/s and record lengths up to 500 K and compresses them to 500 pixels to produce the maximum display content.

I don't think that any of the TDS7XX scopes had a color CRT or a non-aftermarket LCD. At least I've rooted around in many of them and never seen one. I believe they used the shutter system to avoid problems with RGB convergence that a color monitor would have.

Reply to
JW

My TDS744 has a colour CRT.

Cheers

Phil HObbs

--
Dr Philip C D Hobbs
Principal
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Reply to
Phil Hobbs

and

Nope. It has a monochrome CRT with an LCD shutter glommed onto the front of the CRT tube. There is optical gel between the CRT face and the shutter. When the CRT finally goes bad it's possible to replace it, but you'll need to remove the shutter and put it on the new CRT. A very messy job due to the gel.

Unless somebody has modified your particular scope...

Reply to
JW

of

and

CRT

Sure looks like colour, but I'll take your word for it.

Cheers

Phil Hobbs

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Dr Philip C D Hobbs
Principal
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Reply to
Phil Hobbs

TDS754C,

of

and

CRT

Yes, it looks like color but it is the shutter that does the trick. More detail can be found on page 6 of this document:

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and
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There used to be a document about it on the Tektronix website, but it looks like it's no longer there. The electronics to drive the shutter can be seen here:
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Reply to
JW

Hi JW,

Try this:

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It'll want to save a ~2.9MB file named "TDS". Let your browser do so, and then rename the file so that it has a .PDF extension.

Page 1-3 there has a nice table ranging from the 520D up to the 794D.

Thanks!

This is what a helpful eBay seller told me as well:

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The Tek TDS54X revision A did not have some options available. These are 
communications trigger (2C), optical probe options (3C and 4C), hard drive 
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Reply to
Joel Koltner

I'm amazed how many parts that guy has! E.g., just for TDS500 series scopes alone:

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Reply to
Joel Koltner

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