# WWV/WWVB RCVR Schematic

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Howdy all,

#### stevez

I purchased an "atomic clock" for $15 locally and read the information provided with the unit. What I recall was that the clock would run un-synchronized most of the time but on the occasion that a signal/data was present the clock would reset/update to the current time. The mfr said that a sufficient signal was likely to be received daily for even a very short period in most areas of the country. As I recall, my clock receive frequency was 60 kHz but my memory may be incorrect. I think there is a feature on my clock that warns of more than a certain period of time passing since the last update - not sure if it was 24 hrs, 48 hrs or more. #### Sceadwian ##### Banned I wonder if you could receive the 60khz signal directly with an opamp, all you'd need is a loopstick antenna and some filters. By far the WWVB signal is the strongest at 75kw's but that's a data only signal. However the bonus for the 60khz signal is that the frequency of the 60khz carrier wave itself is a frequency standard. NIST: Time and Frequency Division - Division 847 has all the information. #### Mikebits ##### Well-Known Member If I correctly recall, WWV is transmitted in the HF band at 5,10, and 15 MHz. The modulation is both AM and sideband. You could always try WWV online http://tf.nist.gov/service/its.htm Last edited: #### RadioRon ##### Well-Known Member Last edited: #### bigkim100 ##### Banned I have a clock radio that supposidly sets itself using information provided through the 120v line. It also has battery back up that allows it to be used without the 120v input, so you can set a bogus time while its running on batteries, then when its plugged in, its actualy kind of cool to watch the unit scream to the correct time. I have never seen much info on decoding info provided thru the 120v line. #### MikeMl ##### Well-Known Member Most Helpful Member ... I have never seen much info on decoding info provided thru the 120v line. The time data isn't coming via the ac power line. The clock radio has a WWVB 60Khz receiver and decoder. It may use the AC line cord as part of the 60KHz antenna. Last edited: #### Dean Huster ##### Well-Known Member The "atomic clocks" you buy at Wal-Mart for$15 or \$20 are truly radio-controlled clocks that typically update when you first install the batteries (at least within an hour of installing the batteries) and after that, update the time only once per day, usually in the wee hours of the morning. I don't know that the receiver can be pulled from the clock for use in other circuits.

You can probably make a better clock by simply using an ovenized crystal for the timebase and then setting the clock via WWVB. WWVB is a better source for time as it's signal isn't affected as much by the ionosphere with otherwise causes major phase shifts in the HF WWV broadcasts. The 60 KHz carrier frequency is derived from the master clocks. However, so are the HF carrier frequecies of WWV at 2.5, 5, 10, 15 and 20 MHZ. That's why you could always used them to zero-beat a shortwave receiver's crystal calibrator.

I doubt that the Wal Mart clocks are much more accurate than 2 or three seconds per day. The updates would cause a mohor shift in time.

The clock receiver in those Wal-Mart clocks may not be able to be run "out of their orignal box) in that they may not be able to receive upon demand.

Dean

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