A Simple, Valve Curve Plotter

[ppppenguin]

I'm a great believer in hooking up ad-hoc measurement rigs with a couple of power supplies, odd pots, meters and croc clip leads so I like your basic approach. You can learn a lot that way too. You can also get think badly wrong but that's all part of the learning experience.

Or you could do it in style: http://www.dos4ever.com/uTracer3/uTracer3.html About £160 for the kit at current Euro exchange rates. I'm seriously considering getting one.