LCD DSO advice

[Edward Cain]

   I'm thinking of buying a digital storage o'scope and have been looking at the Instek GDS-1102 and the Rigol DS1102E, both LCD and 100 MHz BW. Anyone here have any experience/opinions/advice on these scopes?
   I currently have 40 MHz and a 100 MHz CRT non-storage scopes but I'm attracted to the small footprint and the storage capability of these newer models.

Thanks,
Ed KJ4JST

[Opcom]

If you can stomach the ugly presentation and slow updating of the waveforms, they have much to offer besides small size.

In some cases, there are things you can do with them that can practically not be done with a conventional scope. Such as finding a repetitive single bad bit in a video data stream from a memory IC. but they do not make pleasing modulation monitors.

It all depends on what you want to do with it.
For alignment of radios or scrutinizing data, it is fine.
For intense scrutiny of an unpredictably-timed high frequency signal artifact, it is not the best.

Instek GDS-1102 250MSa/s Real-Time = about 25MHz tops (10 points per cycle). More like 10MHz (25 points per cycle).
The 100MHz bandwidth claim comes into play when the machine samples the signal over and over, and fills in the missing points.

This is necessary because the A/D converter may be fast enough to take samples, but there is a bottleneck somewhere, like transferring those numbers to memory, etc.

25GSa/s Equivalent-Time Sampling means it goes back and samples the signal at 250MSa/s 100 times then displays what was found. If the signal changed, it might not be seen and/or takes some extra skill to interpret what happened.

It is the real-time sampling rate that really matters, unless you have a repetitive waveform. Rigol DS1102E has a 1GS/s realtime rate according to the published info. It is likely the better one?

Since you already have analog scopes, adding a digital one would be an improvement to the toolbox and you could have the best of both functionalities.

[Edward Cain]

Thanks Opcom,
   The real time limitation you mention is just the type of info I was looking for. I think I'll look for something else to spend my money on.

Ed