Charles,
I looked at my thing with a big highBW DSO from LeCroy; i zoomed in, the out put signal still looked awful when amplitiude was close to zero.
i am not too much a wiz of discrete SS circuitry but with opamps i am familiar.
Just looked into my AnalogDevices databook, they have cheap multiplier ICs. Like AD633.
One input is the sine wave, the other the decay from an RC switched off. the AD633 can deliver 40mA with output shorted, so a series output resistor determines output Z.
See, i build the thing, maybe make a PCB, then i move on with more important tasks w/o caring if i could squeeze another few cents out of the electronics.
I looked at my thing with a big highBW DSO from LeCroy; i zoomed in, the out put signal still looked awful when amplitiude was close to zero.
i am not too much a wiz of discrete SS circuitry but with opamps i am familiar.
Just looked into my AnalogDevices databook, they have cheap multiplier ICs. Like AD633.
One input is the sine wave, the other the decay from an RC switched off. the AD633 can deliver 40mA with output shorted, so a series output resistor determines output Z.
See, i build the thing, maybe make a PCB, then i move on with more important tasks w/o caring if i could squeeze another few cents out of the electronics.