- The NOAA Weather Radio Signal
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- 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 !
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- Reliable Local Reception
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- 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 100 miles of a NOAA Weather Radio
transmitter, then you can try a few things to improve signal reception.
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- I can hear the signal, but it's weak and scratchy...
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- 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.
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- It's still pretty scratchy and weak...
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- 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.
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- I still can't hear anything and I live within 100 miles of the
transmitter...
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- 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.
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- If you still can't pick up the NOAA Weather Radio signal, then
please contact the NOAA Weather Radio Focal Point at our office.
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- NWR Focal Point
- National Weather Service Forecast Office
- 2341 Clark Carr Loop SE
Albuquerque, NM 87106-5633
- or
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- E-mail: sr-abq.webmaster@noaa.gov
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