Since the late '70's, I've been using a solid-state TEK portable 'scope with two channels, both internal and external triggering, and with delayed sweep capability. This started out with a TEK 465 (100 MHz) and soon became a 475A (250 MHz) with the DM44 multimeter/counter/timer. I still use the latter, with complete satisfaction, though I also have a TEK 2467B, which was bought not for its 4 channels or its 400 MHz bandwidth, but for its microchannelplate photomultiplier, which enables me to see rarely recurring events such as occasional metastability on the signals under study. There's a no-photomultiplier version of this instrument, the 2465B, which might be just the thing for a current-generation developer.

I recently bought a couple of 'scopes for a client and went to eBay for them. I've found that a TEK 475 (200 MHz) costs, typically, <$200 or perhaps $50 more for the 'A' version (250 MHz) when the DM44 option is installed.

I've also noted that there are many logic analyzers avaialble at very reasonable cost.

For microcontroller design, an instrument capable of sampling at 4x the clock rate ought to be adequate, and, with a little experience, what the logic analyzer will do, among other things, is tell you where to attach the 'scope for further study.

If you ask the right questions, buy the instrument in a "complete" state, i.e. with all its attachments/accessories, it's unlikely you'll be "burned." If you take the transaction too lightly, expect the seller to do your work for you, your chances of being slighted go up considerably.

If you buy an oscilloscope, whether new or used, be certain you know what ancillary equipment you'll need, e.g. probes, etc. Likewise, if you buy a logic analyzer, you should be familiar with it at least to the extent that reading the manual will prepare you. In short ... get the manual first, read it, and from that you'll know how to verify that the instrument you obtain is properly functional. It's very important you know what equipment you need when looking for a logic analyzer, BTW. Often the pods, lead sets, ground straps, pin-grabbers, etc. cost more than the instrument itself if you buy them separately. Many used logic analyzers, though fully functional in the condition they're sold, are totally useless because they lack some critical component. Further, if you intend to move data from the LA to your PC, you'd better know what software is required and how you're going to get it.

good luck!

Richard Erlacher