The NIST WWVB transmitter antenna is very massive and very well documented: https://apps.dtic.mil/sti/pdfs/ADA299080.pdf
For receive on VLF there is no reason to go so big. A short whip produces plenty of atmospheric noise so there’s no purpose at going bigger. A loop (including ferrite core loop) has a useful null to remove local noise sources. A tuned loop with reasonable Q helps reject a lot of noise before it reaches the first active stage. Tim N3QE > On Oct 9, 2020, at 5:14 PM, John C. Westmoreland, P.E. > <j...@westmorelandengineering.com> wrote: > > Bob, > > Thanks for the answer; but does anyone actually have a documented > specification posted for one of these 'massive' WWVB 60kHz antennas > someplace? > > Thanks. > > 73's, > John > AJ6BC > > >> On Fri, Oct 9, 2020, 08:35 Bob kb8tq <kb...@n1k.org> wrote: >> >> Hi >> >> At least to me, anything dimensioned in the 100’s of feet is “massive” >> compared to >> the rod antennas normally seen in WWVB use …. >> >> The other point being that if the antenna is some sort of large loop, it’s >> going to be >> a good long ways away from the receiver. You get both a larger signal >> voltage and better >> isolation ….. >> >> Bob >> >>> On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < >> j...@westmorelandengineering.com> wrote: >>> >>> Hello All, >>> >>> Are there any design details someplace regarding these massive antennas? >>> >>> Thanks, >>> John >>> AJ6BC >>> >>> >>>> On Thu, Oct 8, 2020, 19:27 paul swed <paulsw...@gmail.com> wrote: >>> >>>> Hello to the group. >>>> Ray as Bob mentions you are taking a 10s of uv signal to a logic level >> of >>>> maybe 4V. >>>> If the loop is any place close to the divided down signal, it will >>>> oscillate. It would take incredible shielding to protect the receiver. >>>> Thats why you often see a solution that doubles to 120 KHz and modifies >> the >>>> detectors to work at that frequency. That means hacking the radio >>>> internally. Not fun. The other really annoy effect is that the doubling >>>> slips phace due to noise and propagation. So if charting suddenly you >> get a >>>> 180 degree flip. Thats messy. >>>> The doubling solution can work. Search for carter and there are several >>>> others. >>>> But having tested and used all of the alternates and lots more on the >> east >>>> coast decided they were too much trouble. You should see the box of >> boards >>>> I have chuckle. >>>> For me I am very happy with the d-psk-r. Though in being above board I >>>> designed version 1 and Rodger and I did version 2. Its solid and no >> mods to >>>> any receiver. Everything has always been released to the time-nuts >> group. >>>> As they say have fun. >>>> Regards >>>> Paul. >>>> WB8TSL >>>> >>>> On Thu, Oct 8, 2020 at 5:39 PM <rcb...@atcelectronics.com> wrote: >>>> >>>>> Bob, >>>>> >>>>> I am using a ferrite rod antenna for the receiver. No outside antenna. >>>>> >>>>> Ray >>>>> >>>>> -------- Original Message -------- >>>>> Subject: Re: [time-nuts] WWVB Dephaser Question >>>>> From: Bob kb8tq <kb...@n1k.org> >>>>> Date: Thu, October 08, 2020 12:40 pm >>>>> To: Discussion of precise time and frequency measurement >>>>> <time-nuts@lists.febo.com> >>>>> >>>>> Hi >>>>> >>>>> A lot depends on your antenna setup. You can also swamp out the >> incoming >>>>> WWVB signal……. >>>>> >>>>> Bob >>>>> >>>>>> On Oct 8, 2020, at 2:07 PM, <rcb...@atcelectronics.com> < >>>>> rcb...@atcelectronics.com> wrote: >>>>>> >>>>>> I have read several different articles where the WWVB phase shift is >>>>>> eliminated by doubling the signal to 120 kHz. Several members of the >>>>>> list have built these units. >>>>>> >>>>>> Assume I build a circuit to double the incoming signal and use a >>>> schmitt >>>>>> trigger to get a 120 kHz square wave. If I then divide that signal >> back >>>>>> down to 60 kHz will that signal be strong enough to swamp out the WWVB >>>>>> signal? I'm guessing it will be since it is at the 5 volt level and >>>>>> somewhere in the +25 dBm or greater range. >>>>>> >>>>>> 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. >>>>> >>>> _______________________________________________ >>>> 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. >> > _______________________________________________ > 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.