I'm experimenting with some low noise regulators, and want to do some meaningful measurements to compare them (and hopefully compare to published specs).
I have an HP 3561A FFT analyzer, which can probably be beaten these days by a sound card, but has the advantage of absolute calibration and GPIB to dump data. I also have a very low noise 40dB audio amplifier that covers <10 Hz to >100 kHz. I've tried just looking at the regulator output with the analyzer, with and without the amp, but am not sure what I'm seeing. In particular, even with a capacitor to block the DC, the analyzer indicates "Overrange" at a reference level below -5 or so dBV. That puts most of the noise spectrum below the bottom of the screen. Any suggestions on an appropriate test configuration, and on how to get readings that directly relate to the root-Hertz value shown by regulator data sheets? Thanks, John _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.