“Build” your own WeatherRadio receiver for less than $20!

Yes, thanks to the proliferation of the RTL-SDR project out there, you can have your own WeatherRadio receiver for less than $20! (Note these instructions are the 10,000 ft. view of what’s to be done. I’d assume that you have some RF experience before you even try this out.)

You’ll need the following materials:

  • A TV Tuner that features a RTL2832U Chipset (Tuner wouldn’t matter, although if you plan to use the dongle for other purposes go select one carefully)
  • Some bare copper wire
  • The RTL-SDR software stack (If you’re on Windows, look here)
  • SDRSharp
  • MCX connector to your favorite RF Connector. You can find those easily all over Google

For the bare copper wire part, you’ll probably want to build a quarter wave antenna. Those are easy to design and construct. (hint: Use the wavelength formula and multiply it by a 1/4, you’ll get your length that way)

After you get your hands on the TV tuner with that said chipset, you’ll want to install the RTL-SDR stack for your appropriate OS. Those instructions can be found in the RTL-SDR wiki.

Now at this point you have 2 options – you can either directly attach the TV Tuner dongle to your machine or have the another machine to stream the IQ signal to another machine on your IP network. Yes, since rtl_tcp is based on IP, you can in theory stream it over a WAN link given if you have the bandwith for it.

Now time for the tuning part – If you have a service monitor, then you can use that to generate a FM signal. Since your service tuner is presumably correctly tuned, you can use that to offset the PPM error of your RTL-SDR dongle. For my dongle that I bought off some random place, I found it to be +70. Record that value and use it when you fire up SDRSharp.

If you don’t have a service monitor, you can always use your local FM stations to tune your dongle. Unfortunately as I don’t have a service monitor, that’s what I used. Under normal conditions, it’s almost next to impossible to use a local FM station to tune the dongle as they typically don’t have much dead air time. However if you can find a FM station that has a reasonable length of dead air, you can use that window to tune your dongle to the right PPM correction value. The spectrum/waterfall view is your best friend at this point.

After tuning your USB TV dongle, try tuning to the follow frequencies:

162.400 162.425 162.450 162.475 162.500 162.525 162.550

Again they are in MHz, not KHz! And no, you typically can’t tune to those frequencies with your regular FM radio without modifying the tuner.

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