On Sat, 11 Sep 2004 21:16:40 +0000, Matthew&Wendy wrote:

On and around August 31, 2004, I was in North Carolina. I was receiving a
signal that could be heard from 4520 to 4560 kHz. On AM, it sounded like a
hi-low-hi alarm or tone. On USB, the tone is a "ray gun" from high to low,
snip

CODAR it's been there for years