The NOAA Weather Radio signal travels at the speed of light with a wavelength of about 1.85 meters, or just over 6 feet in length. At this speed, the signal would circumnavigate the earth 7 times in 1 second, yet the terrestrial coverage of the NOAA Weather Radio signal is much more limited. This is because at Very High Frequencies (VHF), radio waves overshoot distant locations. Relative to the traveling radio wave, the ground below recedes due to the earth's curvature. The radio wave continues on its way into space reaching the outer fringes of the solar system in a little over 5 hours time. Mountains and unusual atmospheric conditions can dramatically alter the terrestrial coverage pattern of the NOAA Weather Radio signal. Tropospheric ducting and ionospheric refraction, on rare occasions, have been known to carry VHF radio waves over hundreds or even thousands of miles. The current phase of the 11-year sunspot cycle will likely result in more frequent occurrences of ionospheric propagation through the turn of the millennia. Imagine hearing the coastal marine forecast from your kitchen on the plains of Nebraska!
If you can receive the NOAA Weather Radio signal clearly, from inside your home, then you need not make any changes. If however, the signal is weak, scratchy, or nonexistent and you live within 40 to 50 miles of a NOAA Weather Radio transmitter, then you can try a few things to improve signal reception.
The higher the antenna, the better. If your weather radio has a built-in antenna, try moving the radio to a higher spot, like a shelf or bookcase. Also, moving the radio to the area of your home facing the transmitter location, especially near a window, can produce a marked improvement of the signal.
Okay, let's try something else. Remember that the wavelength of the NOAA Weather Radio signal is around 6 feet in length. This means that an antenna resonant to the NOAA Weather Radio frequencies (162.400 MHz - 162.550 MHz) will best serve listening at a length of 6 feet or greater. To achieve this, cut a piece of copper wire to extend the overall length of the antenna to 6 feet or longer. Attach the wire to the end of the radio antenna by using an alligator clip, or any clamping device, which will ensure a steady contact of the copper wire to the radio antenna. Ideally, it is best to extend the wire vertically and as high up as possible. Extending the wire horizontally along the ceiling may work for you, but the NOAA Weather Radio signal is vertically polarized, meaning by theory, a vertically extended antenna will out perform a horizontal one. Do what works for your locale.
I still can't hear anything and I live within 50 miles of the transmitter...
If you have a weather radio with a built-in, fixed antenna, you may be out of luck. We've done our best in the above steps. However, if your radio has an external antenna jack, or a detachable antenna connection, then we have the means to employ an outdoor antenna. You can attach a coaxial cable from your radio to an external antenna mounted on the roof, in the yard, or on a balcony. Mounting the antenna outdoors and perched high will vastly improve the signal reception. But it does not come without a price. If you mount an outdoor antenna you must make provisions against the danger of lightning. This is done by grounding the antenna. Please consult your local electronics or radio outlet on the proper way to ground your radio system. Many popular handheld radio scanners have the capability to tune into the NOAA Weather Radio signal with the press of a button.
If you still can't pick up the NOAA Weather Radio signal, then please contact the NOAA Weather Radio Focal Point at our office.