[time-nuts] WWVB Dephaser Question

[paul swed]

Seriously nice 1mv yikes! Big antenna. I used the small loop antenna
some2-3 ft diameter. In Ma. that always was something like 10-30uv during
the day. Now with a 10' per side square loop its a solid 60-200uv per day.
Night always goes way up even to the 1mv and higher level.
I am also challenged often by MSF out of England. It can easily
override wwvb.
The antenna has about 800Ft of wire. Its actually made of shielded ribbon
cable with preamp and line driver. Really no magic. Transistors are 2n3904s
Cheap cause lightning likes them for lunch. The antenna is 140' from the
house so no real leakage issues.
You arr right your leakage is not 5V. Really really hard to say what it
would be. But much of the noise would actually travel down the coax to the
antenna. What I do know is that in experimenting on occasion there was
enough leakage to upset things.
The simple 2-3 devices never worked worth a darn out here and I tried all
of them. Simple is a good way to design, but not in New England. For you I
would follow the max carter approach. Yes you have to hack the receiver but
its simple.
I hate hacking these beautiful receivers so thats why the dpskr exists. I
wanted the receivers to work like they used to without unique hacks for
each one. The latest dpskr has 11 outputs. Hard to believe I have used most
already.
Regards
Paul
WB8TSL

On Fri, Oct 9, 2020 at 12:20 AM <rcbuck at atcelectronics.com> wrote:

> Paul and Bob,
>
> Thanks for the comments. I figured I wouldn't be able to get a 60 kHz
> signal anywhere near a WWVB receiver. I just wondered how bad the signal
> leakage from the divider IC would actually be. It is at a 5V logic level
> but I don't know if that means 5V of signal radiation.
>
> I was trying to come up with a simple way (2 or 3 IC solution) to detect
> the phase changes to decode the time data. I'm not interested in using
> the signal for frequency measuring purposes. Doubling to 120 kHz doesn't
> work for detecting the phase change because the change disappears.
>
> I've looked at the block diagram of the ES100 module for hints. They are
> doing something that doesn't require a lot of  processing power as they
> are running the processor at 16 MHz. I guess the processor could have a
> PLL in it to increase the CPU clock speed. Somehow they are using that
> 16 MHz as part of the demodulation scheme. They show the ADC and
> oscillator feeding into a demodulator block. But 60 kHz isn't an integer
> divider into 16,000,000.
>
> Paul, so far I only have 5 or 6 boards but I'm sure I will have more as
> I continue testing. I'm in Phoenix so the WWVB signal is fairly strong
> here. The WWVB coverage maps show the signal as being 1mV during the
> day. I know my wrist watch will synchronize during the day when I
> replace the batteries.
>
> Ray
>
> -------- Original Message --------
> Subject: Re: [time-nuts] WWVB Dephaser Question
> From: paul swed <paulswedb at gmail.com>
> Date: Thu, October 08, 2020 3:43 pm
> To: Discussion of precise time and frequency measurement
> <time-nuts at lists.febo.com>
>
> 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
> > >
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