Clock/Calendar Project: The Radio Receiver

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Well the first thing I needed was the WWVB receiver. I wasn't going to try to make one myself because that would be a whole project in itself and really not my specialty. I'm sure I would not end up with something that would work as well as what an expert made.

So, I looked around the web for some place that sold a WWVB receiver module and antenna. I found a few, but unfortunately none of them had any for sale now; the model that they had sold was now discontinued for some reason with no replacement.

I found one place that seemed to be a manufacturer, but they wanted more for a module and antenna than the cost of a cheap radio controlled clock that could be bought commercially, and I wasn't comfortable buying from such a place.

Instead, I took a chance and bought the cheapest commercial radio controlled clock I could find in the hopes that it would contain a WWVB module and antenna that would be easily extractable.

Here is a picture of that clock, brand new in its package:


And here is a picture of it opened up:


The picture is a bit blurry; I must have done it freehand. I think it's clear enough to see the antenna at the top, and to the left of the PCB you can see that the WWVB receiver is indeed a separate module soldered into the larger PCB. The red wires are Kynar wire-wrap wires I attached to the header pins of the module to probe to make sure I knew what each of them did.

Here is a picture after I extracted the antenna from the clips and glue:


And here is a better picture with the antenna extracted and the main PCB and LCD display removed from the case:

In this one it's clear to see the small module attached to the antenna and the four small pins that are soldered to attach the module to the main PCB.

And finally, here is the antenna and WWVB receiver module completely extracted from the clock:


Those four pins are the interface to the module. Two are for power and ground. One is to enable or disable the receiver (probably for power saving since it's from a battery controlled clock). The final pin is the demodulated WWVB signal that I need to look at to determine the time code.

So that's how I got the heart of the radio controlled clock/calendar!

Next time I will discuss the other parts I used to complete the design.

 

I haven't, but I'll check to see if it has one the next time I take a picture. It's just a little point-and-shoot thing.