It's not just the antenna's fault. Signals in a city propagate like
light in a maze. They are impeded by buildings, but at some
frequencies refract around buildings. Since many signals bounce off
of buildings and other structures, they occasionally interfere causing
"null spots" or "fast fades". There is also ground-effect attenuation
(ground interference from ground reflections) which can severely
reduce a signal.
Your best bet is probably to find a channel at the lowest frequency
possible, like AM 580 because lower frequencies can go around corners
more easily.
Mount the antenna as high as you can (e.g. consider buying headphones
with a built-in AM radio.) Most low-cost antennas are polarized
dipoles which means they favor signals coming from the horizon, and
are much less sensitive to signals from space or from the ground.
This means that once you have pointed the antenna STRAIGHT UP, you
should try to avoid tilting your head because this will cause an
immediate loss in signal strength. Alternately, you might get an
antenna that is less polarized but I don't know where you could find
such an antenna and you would need a better receiver.
Finally, make sure to find a radio with ALC, or automatic level
control. circuitry tries to keep the volume at the same level on a
constant basis. This might be helpful for pure attenuation fades, but
would not be useful for nulls or shadowing fades.
- Don Gillies
San Diego, CA
front end of the
E Willson <
[email protected]> writes:
>To most serious cyclists this may seem like blasphemy but I would like
>to listen to a radio on my daily trip. I have tried several portable
>radios, but none can keep a constant volume as the bike changes
>direction. It seems that the antennas are very directional, so that when
>the bike changes direction the signal strength changes drastically. This
>is true on either AM or FM. Any info on how to setup a radio so that the
>signal strength is adequate and uniform would be appreciated.
>Thanks,
>EJ in NJ