[time-nuts] WWVB software for PC

Vlad time at patoka.org
Wed Nov 2 13:46:55 EDT 2016


Chris,

Thanks for the quick reply ! I am thinking to use something like 
Raspberry PI + little "periphery" to transmit on 60Khz. May be General 
IO pins and some buffer (like 75179) plus loopstick antenna will do the 
trick. I have a NTP server in my lab which sync by 1PPS coming from 
T-Bolt. So, the source should be good enough to sync the wrist watch.

The uP project I have - was bought as a kit. So, I am not the 
author/creator of that. I just get parts together and put them to the 
nice project box.
I think I am capable to create such thing by myself, but its probably 
not worth to re-invent the wheel. I think the idea is already "in air"
For example: Circuit Cellar 2014 Digital Archive: Issue 288 July 2014, 
page 57-

The phase modulation is interesting feature to have. Its in my "long 
waiting list" to have a look to it more closely and probably try to do 
something like this.




On 2016-11-02 13:07, Chris Albertson wrote:
> If the PC's clock is being disciplined by NTP oe "whatever" the WWVB
> simulator would not even have to "know" and would just use the system
> clock.   So I doubt you will find a simulator that explicitly makes
> use of a reference clock.  For your purpose the PC's clock could even
> be set using Internet pool servers, typically this gets you to within
> a couple tens of milliseconds.  The GPS will keep the PC's clock ate
> the tens of microseconds level, You don't need that for setting wrist
> watch.
> 
> One problem is the new phase modulation that WWVB is using.  If you
> want to emulate that you might want to use an audio interface that can
> output the 60KHz RF signal directly.   Most audio interfaces only go
> up to about 20KHz.    You need the 60KHz interface so you can keep the
> phase aligned with the UTC second.
> 
> Software would be easy to write, just output 60,000 numbers per second
> to the port.
> 
> But if you already have a uP that can simulate WWVB why not just add a
> little bit of code you read the tie of day over a serial port
> 
> On Wed, Nov 2, 2016 at 9:05 AM, Vlad <time at patoka.org> wrote:
> 
>> I am wandering, if anybody seen the projects like WWVB simulation
>> (transmitter) using GPS/NTP/whatever as a time reference ?
>> I have something similar, which is generic PIC MCU with connected
>> WWVB antenna. This box generate WWVB signal for very short range.
>> However its handy for developing/troubleshooting the WWVB receivers.
>> There is no fancy parts on that - just an WWVB antenna, which many
>> "travel radio clock" has under the hood. Unfortunately those box
>> using internal oscillator and every time it needs the time to be
>> setup on it.
>> The reason to have "GPS-2-WWVB" could be use it to sync. some
>> watches without relay on WWVB signal propagation. Sometimes its a
>> challenge to get WWVB in big cities because of location and QRM.
>> 
>> --
>> WBW,
>> 
>> V.P.
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> 
> --
> 
> Chris Albertson
> Redondo Beach, California
> 
> Links:
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-- 
WBW,

V.P.


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