I guess the DS1000Z is an exception then but I find it hard to understand why it can't do it because it is so simple to implement.
I wonder the same thing every time it comes up.
So it seems the DS1054Z can do delayed triggering.
No, the trigger delay function can sort of replace trigger after delay which is useful in its own way but it is not the same thing as "runs after" delayed trigger.
I think I start to understand where the confusion is coming from. David Hess is looking for (delayed) B-trigger. This effectively means having 2 different time bases (time/div).
Oddly enough there were some weird analog oscilloscopes which provided a delayed A sweep. The 2215 being replaced by Pete F has a delayed B sweep but the 2213, which is its lessor brother, has a delayed A sweep which is what simple DSOs should be providing because as you point out, it is so simple. It was pretty complicated for the 2213 though so I do not understand what market Tektronix was thinking of. Maybe it was a way for them to distinguish the 22xx series from earlier oscilloscopes although they dropped this function in the later single timebase 2225 and the single timebase 22xx DSOs never had it.
I never cared much about the B trigger function until I started working with switching power supplies. (1) Set the A trigger to trigger off of the switching waveform, delay to reverse recovery, and then set the B trigger to trigger off of the reverse recovery waveform which would otherwise be difficult to pick out. Now you can view the reverse recovery in real time at any time/div with no jitter.
I remember long ago before I understood trigger after delay cobbling together a little circuit to select the rectifier recovery so I could trigger on just it.
(1) Also mildly useful to track down power line "buzz" in linear power supplies used for audio applications. Check the reverse recovery of the slow power line rectifier diodes just after the peak of the power line cycle. Place a 220 picofarad capacitor directly across each rectifier diode to fix.
"Where this becomes a problem, and this was discussed on these forums more than a year ago, is things like measuring jitter in a 1 pulse per second GPS signal. 20M points over 1 second is only 20MS/s yielding 50 nanosecond resolution which is worse than the jitter of many GPS 1 PPS signals."
Ok I do have to ask, out of curiosity, why would you be measuring the jitter of a GPS signal? Many years ago my apprentice built a master clock oscillator for our workshop and we used the Omega signal as the phase master to drive the local clock. However I'm interested in why you'd be measuring that GPS jitter outside of navigation needs.
The time acolytes have great interest in measuring jitter of the 1 pulse per second timing output available from GPS receivers. This signal is almost always synchronous to the GPS receiver clock which is asynchronous to GPS time itself producing jitter equal to the clock period. This jitter limits precision of a GPS disciplined oscillator over medium timescales unless it is corrected.
I have no idea why somebody would think working on a stereo audio system requires 4 inputs, that makes no sense. In fact most of my work was done by probing with a single channel, and that put bread on the table for many years without the world spinning off its axis. I've never really had much (or any I can think of) need for more than 2 channels.
I might want 4 channels so I could use them in pairs to make 2 differential measurements without expensive differential probes. Otherwise 2 channels (and an external trigger input) are plenty for almost all applications.
4 channels are also needed to fully decode SPI although as I recall, one of the recent budget DSOs can do it using 2 channels with the external trigger input as a 3rd channel.
While "more is better" in terms of bandwidth, I'm sometimes concerned that at the bottom end of the market (ie where I'm looking) models may be pushed beyond their real practical limits in order to provide better specs. In other words, a series of oscilloscopes, say 50, 100, 200 MHz. While the 200 MHz 'scope may indeed meet the -3db spec for its front end, the rest of the machine may not really be a 200 MHz oscilloscope and is just pushed up there because it looks good on paper. I don't know if that's a fact, but is definitely a concern.
Probing also becomes more difficult above 100 MHz and 200 MHz is as high as it is reasonable to still use a ground lead and that is marginal. For an analog oscilloscope, high bandwidth has another benefit; high bandwidth analog oscilloscopes use higher acceleration voltages producing brighter and sharper displays. For instance a Tektronix 350 MHz 485 with a CRT acceleration of 21 kilovolts has a better display (albeit smaller) than a 100 MHz 22xx series with a CRT acceleration of 14 kilovolts.
There is a use however for a high bandwidth oscilloscope in audio applications; it is very handy for detecting spurious oscillations or "snivets". I wish there was some way to link a video here without embedding it but as Emperor Joseph II would say, "Well, there it is."