From: Conan Ford
Organization: Your Company
Newsgroups: rec.radio.shortwave
Date: Fri, 18 Jun 2004 03:28:38 GMT
Subject: 6315kHz - What is ist?

Greg wrote in
:

6315 kHz - choose your mode. What is it? A beacon of some kind?
Never heard this before.

Greg

27.97N 82.00W


http://homepages.donobi.net/nkarc/2003aug.html - near the bottom, under
"Checking HF Propagation":

"Recently, I came across an article in the March, 1996 issue of QST
entitled “Which HF Band is Open“ written by Frank Wolfe, NM7R. The
article describes the Maritime Coastal Stations and their operation.
“These stations are located all over the world, and are used by ships
for commercial radiotelex traffic. The mode used is called Narrow Band
Direct Printing (NBDP) radiotelegraphy. Also called SITOR, this is the
commercial cousin to our AMTOR mode. The ship station operator uses his
transceiver to connect the ship station with the shore station. The
shipboard operator can then use the worldwide Telex network to send
messages to virtually any commercial teletype terminal.

When message traffic is being sent, you’ll hear the familiar chirp sound
as data is transmitted and acknowledged. These sounds are similar to the
AMTOR signals in the amateur digital subbands. When idle, thestations
transmit a marking signal that serves as a propagation beacon for the
shipboard operators. This allows the operators to determine which
stations they can work, and whether a particular station is busy or
available. The marking signal sounds like a purr-purr followed at
intervals of a few seconds with the station’s call sign, usually
composed of three letters, sent in Morse code.

The stations are commercial and run 10 to 15 kW. An amateur signal might
be two to four S units below the strength of the beacon signal. They
transmit within narrow frequency segments: 4.210 to 4.218 MHz, 6.314 to
6.328 MHz, 8.417 to 8.433 MHz, 12.579 to 12.609 MHz, 16.807 to 16.843
MHz, 19.680 to 19.690 MHz, 22.376 to 22.413 MHz and 26.100 to 26.110
MHz."

Okay, I was aware of the Maritime Coastal Stations and of SITOR. Now I can
attach the sound to the names. The station I heard must have been sending
its idle signal. I did hear another station under it, as Patty indicated.

Good info, thanks!

Greg