By: Steve Hageman

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This project stems from an almost lifelong obsession of receiving WWVB on 60 kHz. Over the years I've built several WWVB receivers and time code decoders. WWVB transmits on 60 kHz and can be picked up almost anywhere in the USA with a suitably designed loop of ferrite loopstick antenna. WWVB has a simple BCD encoded time signal using very slow AM modulation. The time decoding has been done with a PIC and a low cost 16x2 LCD display.

The goal of this current project is to make a world class receiver using DDS digital tuning, all controlled by a PC. I intend to use Analog Devices AD831's to do the mixing on this design. In the past I have mostly used direct conversion, but since I moved to within 20 Mi of LORAN C station operating on 100 kHz, the old designs are having problems keeping time lock . Well, actually they don't lock at all anymore :-(

News Update: On October 19th, 1999 My daughter and I rigged up a 30 turn, shielded, 4 1/2 foot loop on an east-west fence in the yard. WWVB now beams in :), I finally have plenty of signal to decode WWVB time for most of the day. The old receiver probably still needs to have a 100 kHz notch filter, but things are much better.

Mostly I have just a paper design now, although the DDS circuit is leveraged off of my previous designs. I've played around with the mixers some and have built several preselectors.

In September, now December 1997, WWVB (Based in Boulder, CO.) is scheduled to increase power 4x. This should help a great deal.

For more information check out the NIST web site, search for WWVB.

Also see my WWVB decoder page.