Does it sound like this:
http://www.youtube.com/watch?v=ZBsR8cN-FpI

If it does you have heard a jammer. The most prolific user of this type of
jammer is Vietnam, but North Korea also uses a similar one fairly often.
Other users exist, but those two are the most frequent.

At that freq, 12180 kHz, I do not know who they might be trying to jam. The
Sound of Hope does use 12175 kHz, but not at that time, 1415z. Also, the
Chinese normally hit Sound of Hope with the Firedrake jammer, and that does
not sound like a siren. Again to support the Vietnamese jammer I often see
it pop up on fairly random frequencies, often with no station under it being
jammed.

T!


"John_A" wrote in message
...
It sounds like a police siren, in AM mode, now at 14:15 z, any have an idea
what this is ?