Posted to this list just minutes before is a live on-line measurement demo. The hardware used is pretty simple. Just four inexpensive parts (and a computer) http://websdr.ewi.utwente.nl:8901/lichtnet/
On Fri, Jul 1, 2011 at 10:08 AM, Tom Holmes <thol...@woh.rr.com> wrote: > In thinking about how to implement a scheme to make the phase and frequency > comparison using what I have on hand, I considered the following as a > possibility: > > An ARB with a GPS derived 10 MHz reference set to 60 Hz. The one I have has > a very low jitter spec. It actually is a dual ARB so I could use the 2nd > independent channel to calibrate the phase detector > > A phase comparator, which I would have to construct or buy. The phase > difference output would be a DC voltage that could be calibrated. This is > the only piece that I know little about so suggestions on how to create this > would be appreciated. A 2-channel digital scope? A simple IC comparator? > Hey, it's only 60 Hz, how tough could it be? > > A 6-1/2 digit DMM that could either be polled at intervals of a few mSec, or > could be set to capture a number of readings for transfer to the PC. In > either case the data could be time-stamped. > > Sounds like fun! > > Tom Holmes, N8ZM > Tipp City, OH > EM79 > > >> -----Original Message----- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >> Behalf Of Chris Albertson >> Sent: Thursday, June 30, 2011 12:28 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] TEC party: hardware suggestion >> >> On Thu, Jun 30, 2011 at 1:38 AM, Achim Vollhardt <avoll...@physik.uzh.ch> >> wrote: >> > Time-Nutties, >> > >> > how about using a small uC (PIC/AVR) clocked with 100ns instruction > speed. >> > Start = 1PPS from GPS, Stop = 60 Hz Edge? Use internal capture hardware > to >> > count processor cycles in between. >> >> Recently posted plots show that all you need is an AC wall wart >> transformer and two resistors. a uC is total overkill >> >> The xformer and resistor voltage divider works because by dumb luck >> the pin in the rs232 port was designed to accept a signal that looks a >> lot like low voltage AC and even better, already has edge detection >> built in. Also by dumb luck someone already wrote the software to >> monitor the pin's status and time stamp transitions. This really >> is a case of pure luck. >> >> >> -- >> >> Chris Albertson >> Redondo Beach, California >> >> _______________________________________________ >> 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. > > > > _______________________________________________ > 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. > -- Chris Albertson Redondo Beach, California _______________________________________________ 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.