Old sampling scopes that have a diode sampler at the front end manage to avoid problems associated with more modern scopes.
A problem with scopes with amplifiers (and/or ADCs) is that they take a long time to recover from overload. The usual rule of thumb is therefore to ensure the entire signal is visible on the display, not off the top or bottom of the display.
That is a killer problem when trying to measure small perturbations on large (i.e. > the display) signals. A classic example of that is measuring the 0.1% settling time of an opamp, where you are trying to measure deviations that are only 1000th of the signal.
Diode ring samplers avoid the overload problem, because their operation is to detach the scope's amplifiers from the signal except when the signal is being sampled. Hence earlier large signals don't reach the amplifiers/ADCs, and hence they are not saturated.
Most people won't have such requirements, but when you have them you need to avoid non-solutions.
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On 08/05/22 17:08, JOE wrote:
Vintage sampling scopes can provide capabilities that are pretty amazing given the technology available at the time. However, they can be tricky to set up, are only usable with repetitive signals, and are definitely tricky to maintain and repair.
I'd suggest a SS analog scope to use to work on the units you collect. There are many to choose from. My preference for every day work is a 7K mainframe with an assortment of plug-ins. Personally I use a 7904A. I also have sampling systems, modern digital scopes. They all have their uses. If you do go with a modern digital scope I'd suggest a DPO. They better mimic displays you're accustomed to with an analog scope.
