I am working on an AC Voltage Calibrator project. See reference below from reply #82 for the latest version.
https://www.eevblog.com/forum/metrology/an-experimental-ac-voltage-calibrator/75/Am now in need of a very stable amplitude low noise signal source, ~1vRMS 20-20KHz, to drive the calibrator.
I have tested several signal sources, commercial and home-made, and most have fallen short wrt either amplitude stability or noise.
Wavetek Model 80 function generator
Leader LAG126S audio generator
Chinese low distortion audio range generator kit
ASUS Xonar U7 PC USB sound card
Obviously there are dozens of good designs out there that can generate stable audio frequencies. What I am looking for is an affordable one to work with.
Ideally, for this project, a generator that stabilises in amplitude (<60uV/min) within ~30 min and has less than 30uVpp noise on a 1v/1KHz signal would be OK.
Looking for suggestions on equipment or designs. I will post more info and the results of my tests soon.
How good is your audio frequency generator for amplitude and noise in a metrology role?