From the FCC website
http://wireless.fcc.gov/service....issions

One-Way Transmissions

Q: What types of one-way communications are amateur stations authorized
to transmit?

Section 97.111(b) provides for one-way communications. In summary,
auxiliary, beacon, space and stations in distress are specifically
authorized to make certain one-way transmissions. Additionally, an
amateur station may transmit the following types of one-way
communications:
1 Brief transmissions necessary to make adjustments to the station;
2 Brief transmissions necessary for establishing two-way communications
with other stations;
3 Telecommand;
4 Transmissions necessary to providing emergency communications;
5 Transmissions necessary to assisting persons learning, or improving
proficiency in, the international Morse code;
6 Transmissions necessary to disseminate an information bulletin; and
7 Telemetry.

Q: What is an "information bulletin"?

The term is defined in Section 97.3(b). It is a message directed only
to amateur operators and consists solely of subject matter of direct
interest to the amateur service. The control operator of the station
transmitting an information bulletin is responsible for determining
that the subject matter is of direct interest to the amateur service.

Q: Does an amateur station transmitting information bulletins have to
share the channel?

Yes. Section 97.101 provides that each station licensee and each
control operator must cooperate in selecting transmitting channels and
in making the most effective use of the amateur service frequencies. A
specific transmitting channel is not assigned for the exclusive use of
any amateur station. Section 97.101 also provides that no amateur
operator shall cause interference to any radio communication or signal.
There is no exemption for amateur stations transmitting for information
bulletins.

Q: Is broadcasting prohibited?

Yes. Section 97.113 prohibits amateur stations from engaging in any
form of broadcasting or in any activity related to program production
or news gathering for broadcasting purposes.

Q: Is there an exception to this prohibition?

Yes, there is one exception: Communications directly related to the
immediate safety of human life or the protection of property may be
provided by amateur stations to broadcasters for dissemination to the
public where no other means of communication is reasonably available
before or at the time of the event.

Q: What is "broadcasting"?

Section 97.3 defines the term "broadcasting," in the context of the
amateur service, as a transmission intended for reception by the
general public, either direct or delayed.


Todd N9OGL