Thought this might be of interest................

https://www.ebay.co.uk/itm/384042630024?

On Mon, 13 Sep 2021, Ken Eckert wrote:

Thought this might be of interest................

https://www.ebay.co.uk/itm/384042630024?

That "Add to basket" on UK site is a charm :)

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I would guess that this contains one of the TDR generator hybrids used in the SD-24. The same hybrid is used as the (very fast) calibrator on some Tek sampling scope mainframes.
I bought a "parts" SD-24 and was able extract the step generator for use with my HP 54121A. It is significantly faster than the native 54121A step generator.
--John Gord

I used an Agilent 33120A arbitrary waveform generator instead if a time mark generator. It costs less, and you can use it for many other things too. I don't know of there are any important differences which make the 33120A impossible to use, but I was not aware. So I just did it, and it worked fine. The signal you see is from the 33120A.

https://www.jacmusic.com/techcorner/INSTRUMENTS/TEKTRONIX/5113-Scope/Cardiac2-250.jpg

The main feature of the Tektronix 067-1338-0x is the step rise time of under 20ps. The 33120A arbitrary waveform generator is much, much slower.
--John Gord

I see what you mean. Yes 20ps is really fast. I am sure that is usefull for some cases. The 33120A can never do that.

I checked what the 33120A could do with my SC504 scope, which is 80mHz. The 33120A can repeat the signal at 1mHz. I could verify the 0.1uS/div with it. 10 repetitions, and 1/5 of the last division too slow. So 2% too slow. I could not verify the fastest range 50ns/div any more. But at any lower range it is 2% too slow as well. So just when I make no mistake, with the 33120A I could see this 80mHz scope time base is 2% off.