On 11/13/2012 06:04 PM, Tom Metro wrote: > Tom Metro wrote: >> I have several clocks in my house (and a watch) that all set their time >> using the 60 kHz radio broadcast time signal originating from Fort >> Collins, Colorado (callsign WWVB). > You can listen to what this signal sounds like here: > http://www.rescueelectronics.com/WWVB.html > > or here: > http://www.youtube.com/watch?v=0m5AT67Apvs > > > You can find receivers for the signal here (though this one is no longer > sold by Sparkfun): > https://www.sparkfun.com/products/10060 > > >> In any case, I've periodically searched online to see if anyone has >> built a circuit that either acts as a repeater for the WWVB signal, or >> emulates it, using a GPS receiver or Internet NTP server as a time >> source. > I've ran across this thread before: > http://www.radiobanter.com/showthread.php?t=62837 > > which suggests building a large coil as a passive field concentrator. > Others in the thread suggested creating an attic antenna, wiring it to a > preamp, and then inductively coupling the output to your clock (i.e. > running a few loops of wire around the clock's frame). > > Neither approach sounds like it would be effective if you want to boost > the signal to multiple devices spread throughout a house. > > > This thread shows a design for a 60 KHz transmitter driven by a micro: > http://doityourselfchristmas.com/forums/showthread.php?11305-60-khz-Transmitter > > This ntp mailing list posting: > http://lists.ntp.org/pipermail/questions/2011-June/029763.html > > asking about an NTP->WWVB emulator points to a commercial product: > http://www.c-max-time.com/home/index.php > > which costs $487, and is listed as discontinued by Digikey. The vendor > has other similar products, but no pricing or distributor information. > They look expensive. But at least this proves it is a viable idea. > > >> ...a graduate student project to build a repeater. > I think this is the paper (Google Quick View): > > Self-Powered Repeater for Radio Controlled Clocks > https://docs.google.com/viewer?a=v&q=cache:TZugYGZ-V38J:courses.engr.illinois.edu/ece445/projects/fall2010/project3_design_review.pdf+wwvb+repeater&hl=en&gl=us&pid=bl&srcid=ADGEEShH7T398ioCC9AvCDZcsg19K5GXGLi_UWxEfrXpChTdFFV-cJY93myUKG1yON1b4P-F70HpsYJc1dFRKDQXT5CbOV2uiDZ4E3y4SMFiWTtEcf0IyLDzJh5We0jtwTkG9NgOajHR&sig=AHIEtbQmMoopHpA-4JDXb4GO26QJcceKbQ > > (Original PDF): > http://courses.engr.illinois.edu/ece445/projects/fall2010/project3_design_review.pdf > > The paper doesn't address how they planned to handle feedback, nor does > it include complete schematics. It would take some legwork to track down > the student to see if they actually built it. > > > I found a couple of places, one in UK the other in CA. I've got the same problem. My nighttable cl;ock syncs every once in a while, and my watch always syncs because I leave it on the window sill. http://www.pvelectronics.co.uk/index.php?main_page=product_info&products_id=7 http://www.canakit.com/wwvb-nist-radio-time-receiver-kit-wrl-10060.html Out of stock
-- Jerry Feldman <[email protected]> Boston Linux and Unix PGP key id:3BC1EB90 PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66 C0AF 7CEA 30FC 3BC1 EB90
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