Ryo wrote:
Thank you all who responded!
Scott Dorsey wrote:
[. . .]
Also, is there
a table showing which station has which frequency? I live
in Honolulu, Hawaii, USA.

Yes, there a search engine on fcc.gov somewhere. But if you tell
me what frequency you wre listening to, I could probably make a good
guess about what was going on.

Thanks! My favorite station is Hawaii Public Radio (call sign KHPR)
at 88.1 MHz. I couldn't identify the other station. It was so noisy
and it was gone soon after I noticed its existence.

KHPR is occasionally subject to ducting from a station in the Big
Island whose call sign I forget. If you go to the station and look
in the public inspection file, they did a study on some of this stuff
back in the eighties.

What was the weather like outside when this happened?

Hmm. I guess it was a bit cloudy, a lot windy (but when is
it NOT windy in Hawaii? :-), and with some rain from time
to time.

Tropotunnelling or ducting would be my first guess.

This has just occurred to me, though it may well be a stupid
question . . . is it possible that a neighbor of mine is
(illegally?) emitting FM signals? I remember when I was a kid,
there were FM radio transmitters. Plugged into the audio
output of your stereo, such a transmitter sends the sound
as an FM radio signal, so that you can hear the music at the
far end of your house using a plain radio. Such transmitters
aren't sold any longer in Japan, where I'm from. What about
the US?

Yes, this does happen now and then. A lot of folks using XM or Sirius
satellite radio here on the mainland get little FM rebroadcasting boxes.
Some of them can cause external interference if they are not properly
installed. (Are these services even available in Hawaii?)

Next time it happens see if you can catch an ID.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."