[time-nuts] WWVB Dephaser Question

[paul swed]

John I don't think so as not sure how many have built a large antenna.
Certainly any of the old wwvb receivers have details and thats pretty much
what most people copy.
Essentially a 3 foot copper loop with numbers of turns of wire connected
together. Like 25 pair telco cable connected end to end. A large capacitor
is then put across the loop to resonate it at 60 KHz. Then the preamp. Some
use a FET transistor followed by a line driver transistor. Power is sent
over the coax so a blocking cap and inductor.
Really big is 10' by 10' using shielded 36 wire ribbon cable. ( did not use
all 36 conductors it was to much L but 800 ft worth. The shield acts like
the copper pipe and it must be broken so that it does not look like a
shorted loop. Add the cap and preamp.
In this case I built a 2 transistor NPN 2n3904 preamp.
On the large antenna I use a 2 X 6 post 4ft in the ground with cement. A
mast above that to support the antenna and to allow it to be turned a bit
to null MSF.
Thats it no real magic. Its been operational for 7 years with an occasional
transistor replacement. Also coax, darn woodpeckers!
Regards
Paul
WB8TSL


On Fri, Oct 9, 2020 at 5:14 PM John C. Westmoreland, P.E. <
john at 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 <kb8tq at 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. <
> > john at 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 <paulswedb at 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 <rcbuck at 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 <kb8tq at n1k.org>
> > >>> Date: Thu, October 08, 2020 12:40 pm
> > >>> To: Discussion of precise time and frequency measurement
> > >>> <time-nuts at 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, <rcbuck at atcelectronics.com> <
> > >>> rcbuck at 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 at 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 at 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 at 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 at 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 at 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 at 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 at lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>