First, here's the "why" of what I want to do. I repaired my HP 3468a bench meter, but the cal data got lost. I am content if it matches the accuracy of my Siglent 3055, so I plan to use that meter as a transfer standard. Honestly, I don't need a pro level cal.
Ok, with stuff I already have, I can cal almost every function of the meter. The main thing I lack is an AC voltage source in the proper ranges. Since I do some tube stuff, a high voltage adjustable AC supply (say, up to maybe 450 volts or so) could be handy. So I am gonna build one and use it to cal my meter.
My plan is to start with maybe an LM317 based adjustable DC supply, use that to power a VCO, and use a transformer to step up the voltage.
So about the VCO? I know I could do a fixed 60Hz design, but this is for fun too, and I want dumb capabilities I don't need. I'm a hobbyist after all.
So, I'm thinking say, 10s of hertz to maybe a kilohertz. If I ever have to mess with some 400Hz stuff, I'd be covered. I plan to make the thing mcu controlled too, if that matters. I probably don't need the purist of sine waves, but in the spirit of excellence, that's a plus.
My gut says Wien bridge of some sort. But I'm open to anything, including a square wave gen that I filter into a sine. I plan to conjure a simple counter in order to have a readout, and possibly to use as a feedback mechanism to stabilize the frequency. I am looking for an excuse to play with PLLs too if that is a useful element.
Ideas?