Ryo wrote:
The reception of my favorite FM stations has markedly degrade
recently. I've been wondering why. Today, I realized one of
my two radio receivers was receiving a different FM station
at the same frequency while the other receiver was receiving
my favorite station. Both receptions were very bad (noisy).
Eventually, the second receiver switched back to my favorite
station and the receptions of both receivers improved.

I'm puzzled. First of all, is the bad reception of the original
station due to the second station? If so, is there something
I can do? such as complaining to some authority? I thought
the authority takes care of the allocation of radio frequencies
so that overlapping like this will never occur. Also, is there
a table showing which station has which frequency? I live
in Honolulu, Hawaii, USA.

http://www.fcc.gov/mb/audio/fmq.html

Were you able to identify the second station? What is the original station?

Honolulu is an unusual market in that many powerful stations transmit
from low sites within the city. This means that the local stations are
VERY strong - and tend to overload receivers. This can cause a station
to come in on a frequency it isn't actually broadcasting on.

Of course, it's also unusual in that it's a VERY long distance to any
other market! I count 27 FM stations in Honolulu. 13 of them have no
other station on the same frequency anywhere in Hawaii. Four have
another station but it's of less than 250 watts. Seven have another
station but it's in Hilo, on the opposite side of the mountain on the
Big Island. That leaves five Honolulu stations that share a frequency
with a station elsewhere in Hawaii where tropospheric propagation might
be possible.

Propagation to the mainland *is* possible (believe it or not!) but I
doubt it could be strong enough to interfere with the powerful local
Honolulu stations, especially those whose transmitters are in the city.
I think receiver overload is a far more likely problem.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com