I've always noted that casual attempts to pick up 60 Hz with small antennas etc see more harmonics and other trash than actual line frequency. But if you're in an office environment, why not plug something in? It's quite easy to build a simple passive diode clipper/filter that will plug into a wall outlet and which will provide a sort of soft (but clean) squarewave at a voltage level convenient for lab instruments and with good protection against big spikes and other trash riding on the line.
If you're willing to do this and need help with a design, contact me off-list at k8yumdoo...@gmail.com. Dana On Tue, Jul 2, 2019 at 6:00 PM jimlux <jim...@earthlink.net> wrote: > There's some designs on the list (using a PICPET, for instance) to > measure the local line frequency and phase.. > > but the schemes we've discussed require connecting to the power line in > some way. > > What about a non-contact sensing approach? Something you could put in a > box and it would pick up the electric or magnetic field as the input? > > Just how strong is the field anyway? I've always been trying to cancel > or shield it or reduce it in some way, so I've never actually measured > it in a calibrated way. A 10cm antenna on a 1Meg scope probe looks like > about 40 mV peak to peak (for the 60 Hz component) along with lots of > other high frequency stuff (40 kHz and a few hundred kHz in my office) > from switching power supplies. > > I realize that in a office/industrial area you'll probably pick up all > three phases in some way. > > What about using a small loop? or a magnetoresistive sensor (like the > compasses in phones)? > > Has anyone tried any of these? > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
