turn your expensive oscilloscope into a $5 clock

Isn't that how they make multi-channel, multi-gigahertz digital sampling scopes? (More or less) Some high-speed ADCs, a bit of logic and a display.... :)

That?s exactly how they do it. Start with four DC to 20GHz preamps, split the output of each preamp to four 12.5GS/s ADCs each with a phase shifted clock and connect each ADC to a demultiplexer driving wide slower memory. While you are at it, take a split off your preamps and send it to your trigger comparator chip. (When you?re at Radio Shack, be sure to ask for the premium trigger chip). Now you just have to read back the acquisition memory, convert it to a raster image and send it to your $5 garage sale TV. Voila, you have a 20GHz, 50GS/s digital scope.

Bruno, this is cool. 5 bucks is a deal. If the freight is not too expensive, I'm going to order one.

Rene

Or knock on the door of the building supervisor and say "I will give you this expensive oscilloscope if you tell me what time it is."