[GreenKeys] Western Union Time Service

Doug Alderdice ka2wft at arrl.net
Thu Jan 8 21:30:40 EST 2009


At 07:51 PM 1/8/2009 -0600, Jim Haynes wrote:
>Yeah.  I have a friend who built a driver for the clock based on an old 
>Rado Shack product "time cube" that was a WWV receiver.  Those are no 
>longer available either.
>
>I found a cheapish WWV receiver on ebay, but it is totally undocumented 
>and microprocessor controlled, so I haven't taken time so far to try to 
>figure out how it works.

Don't forget that many of the one-board GPS receivers for embedded systems 
like the Rockwell Jupiter board or Motorola Oncore (the GPS rx in the early 
On*Star systems) and often available on the E-place have a user-accessible 
1 pulse-per-second "heartbeat" synched with the GPS constellation.  I have 
a spare board here waiting for time to play with that and use it to 
accurately control an old IBM time card punch clock I have.  Feed the 1 PPS 
into something that counts off 60 of 'em and pulse the minute on the clock, 
or count an hour to synch your SW clocks, etc.  You could also read the 
data stream out of the GPS boards with a microcontroller and pull out the 
time and work with it accordingly.  There's also a higher frequency very 
accurate signal available out of them (10 kHz?) that you can do things like 
synchronizing transmitters and receivers.  A guy in the radio club here is 
doing that to keep the club's UHF repeater spot on frequency; the thing is 
never more than a cycle or two off, if that!

The mind reels with possibilities...  now that we've really wandered away 
from teleprinters!!

73,

Doug, KA2WFT




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