Hi I'm a teacher with a growing interest in electronics and robotics. I want to add a little more electronic theory to my class and start a robotics/electronics club. I know theory, but am lacking in practical experience. I've been thinking about buying an oscilloscope so I can show the students some of the transient effects and as an analysis/ learning tool for the club. I've spent the afternoon looking at stuff on the internet and there are a lot of general rules of thumb and how to use articles, but what I need is "what to buy" advice. I want to be able to show kids switch bounce, measure the flash rate of an LED, see the waveform of an RC circuit, see ripple and see how a cap can reduce it. It will have to be fairly simple stuff in the beginning, but over time I would like them to be able to build some fairly sophisticated analog and digital projects. So what do I need? Price is a concern as I'll have to buy the scope myself, I've rejected the sound card oscilloscope solutions as they seem too crude, though they're cheap enough that every student could have one, but what else? I think storage is a must and at least 2 channels, but what bandwidth and sampling rates will I need to provide good examples of haw circuits behave? Are any of the PC peripherals really useful? If so are their kits I could buy and assemble? Can I pickup a scope on eBay that will do the job for a reasonable price? What do I look for? Any recommendations would be appreciated.