Hello to the group. It is really hard to see. I have seen it and it is as the NIST document states. It happens maybe every second or so out of 60-120K cycles I used a HP 3335 that allowed me to slew the phase. Its really hard to catch. Trace up very bright also. Regards Paul
On Mon, Jul 27, 2020 at 8:08 PM Dana Whitlow <k8yumdoo...@gmail.com> wrote: > That phase reversal when the waveform is not at a zero crossing probably > adds appreciably > more high frequency content than a phase reversal at a zero crossing. In > ham parlance, > I'd say it would introduce pretty severe "key clicks". > > Have you considered writing a program to generate the right waveform to > load into your > AWG? Then you'd have complete control. > > Dana > > > On Mon, Jul 27, 2020 at 6:08 PM <rcb...@atcelectronics.com> wrote: > > > I have been playing with the 74HCT4046 PLL over the last couple of days. > > I have the VCO running at 90 Hz and my AWG running at 90 Hz as the input > > source to lock the loop. The AWG is modulating the 90 Hz sine wave with > > a PSK signal at a 9 Hz rate. > > > > I slowed the signals down from 60 kHz to 90 Hz to better observe the > > phase reversal. I could see the reversal at 60 kHz but could not capture > > it for a single sequence photo. Attached is the jpg of what the signal > > looks like when it performs a 180 degree reversal. With my AWG the > > reversal always occurs at the top or the bottom of the sine wave instead > > of at the center like John Lowe shows in the WWVB document. > > > > I ordered parts from Mouser this morning to build the RF front end. > > Hopefully I will be able to get a clean enough sine wave from WWVB to > > see what their phase reversal actually looks like. Then I will have to > > come of with the best/simplest way to detect the change. As was > > previously mentioned, the normal phase needs to be detected at the top > > of the minute. That means it will take at least 2 and probably 3 minutes > > to obtain a valid date/time data transmission. > > > > Ray, > > AB7HE > > > > _______________________________________________ > > 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. > _______________________________________________ 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.