It could be one of the GPS correction signals that transmit in the 300 to
315kHz range.

Pete

Jim Shaffer, Jr. wrote in message
news
On 05 Sep 2003 20:37:59 GMT, (J999w) wrote:

Sounds like the USCG ... got one here in Milwaukee 297khz ... sounds
like RTTY
(teletype) ... it's 30db over S9 here ... makes a nice reference signal
for
antenna work. I forget the official name for this type of LW service.

NAVTEX is only broadcast on one frequency (518) as far as I know. I
wonder if
you might be hearing Differential GPS?

Speaking of longwave, I have a loud digital signal on 100 kHz. Does
anyone know
what it is? LORAN?