Starting 1970 I used a modified Tracor 599H on WWVB with excellent results. It had a mechanical counter with 100 nsec, resolution. Noisy but perfect. Yes you have to take Ionosphere sunrise and sunset in to consideration and the hourly shift, but being a very early riser 4AM because of Europe no problem. Better than 2 E-11 per day and 4 E-14 per month.
In the 90 ties with my FRK having temperature and aging control frequency was better than 1 E-12 all the time. Bert Kehren In a message dated 11/19/2018 9:58:39 PM Eastern Standard Time, [email protected] writes: HF propagation of WWV or WWVH is horrible compared to VLF propagationof WWVB at 60 kc. In this video the 5 mc WWV signal from Ft Collins,Colorado is being received in New Jersey. It was compared against astable 5mc crystal source. You can see a shift of a few cycles persecond over a few seconds. This is due to the movement up or down ofthe ionosphere at a substantial fraction of the speed of sound. Iunderstand that it can be as bad as a part per million short term atsome frequencies. The 10 mc and 15 mc broadcasts may be better orworse at various times of day. I have spent many hours watching WWVB in the days when they had theold format. It was good to a part per billion except just beforesunrise and just after sunset. Then it degraded to either + or -5parts per billion for about 30 minutes. https://www.youtube.com/watch?v=nf9KWfS9QBs _______________________________________________time-nuts mailing list -- [email protected] unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
