On Mar 16, 2012, at 1:32 AM, Peter Monta wrote: > Attached are some more renderings of John Seamons' WWVB data. This is > what one might expect from a receiver that knows when the phase > reversals happen and takes them out noiselessly---re-reversing the > out-of-phase bursts to recover an approximation of the usual WWVB > signal.
Thanks for the additional analysis Peter. Odd that there is significant phase jitter. I've added to my website the only other significant recording I made: ten minutes in the dead of night (2:27 AM MST, 9:27 UT). http://www.jks.com/wwvb/wwvb.html#10-min The phase data I extracted is the same as the two minutes of data I captured earlier. A constant pattern that repeats every minute. Certainly not the full protocol as described in the NIST paper. So maybe this test was to simply evaluate the phase modulation effects on receiving equipment (in which case it's shame we didn't find out earlier so we could do more boat-anchor compatibility testing). In an earlier message Dennis Ferguson points out that the paper doesn't fully specify the 11/14-bit minute-sync and 60-bit hour-sync codes. So it's not clear what they were actually transmitting. They do talk about using the 11-bit Barker code for autocorrelation. But the sync bits transmitted only match the Barker code if you interpret them a little bit out-of-order. _______________________________________________ time-nuts mailing list -- firstname.lastname@example.org To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.