630 m band

Antennas used to transmit in the 630 m band must not exceed 60 meters in height above ground level.

Amateur stations in the 630 m band shall only operate at fixed locations. Amateur stations shall not operate within a horizontal distance of 1 km from a transmission line that conducts a power line carrier (PLC) signal in the 135.7-137.8 kHz or 472-479 kHz bands. Horizontal distance is measured from the station's antenna to the closest point on the transmission line.

Prior to commencement of operations in the 630 m band, amateur operators shall notify the Utilities Telecom Council (UTC) of their intent to operate by submitting their call signs, intended band or bands of operation, and the coordinates of their antenna's fixed location. Amateur stations will be permitted to commence operations after the 30-day period unless UTC notifies the station that its fixed location is located within 1 km of PLC systems operating in the same or overlapping frequencies.

Amateur stations in the 630 m band shall not cause harmful interference to, and shall accept interference from: Stations authorized by the FCC in the maritime mobile service and stations authorized by other nations in the maritime mobile and aeronautical radionavigation services.

Amateur stations in the 630 m band causing harmful interference shall take all necessary measures to eliminate such interference - including temporary or permanent termination of transmissions.

Amateur stations transmitting on the 630 m band may not emit an angle-modulated (FM or PM) emission that has a modulation index greater than 1 at the highest modulation frequency.

Amateur stations transmitting on the 630 m band may not emit a non-phone emission that exceeds the bandwidth of a communications quality phone emission of the same modulation type. The total bandwidth of an independent sideband emission (having B as the first symbol), or a multiplexed image and phone emission, shall not exceed that of a communications quality A3E emission.

Only a RTTY or data emission using these specified digital codes may be transmitted on the 630 m band: Baudot, AMTOR, ASCII, or any technique whose technical characteristics have been documented publicly, such as CLOVER, G-TOR, or PacTOR, for the purpose of facilitating communications.

Amateur stations transmitting data emissions on the 630 m band may not exceed 300 bauds, or for frequency-shift keying, the frequency shift between mark and space must not exceed 1 kHz.

No station may transmit in the 630 m band with a transmitter power exceeding 500 W PEP or a radiated power exceeding 5 W EIRP, except that in Alaska, stations located within 800 kms of the Russian Federation may not transmit with a radiated power exceeding 1 W EIRP.

Contest activity shall not take place on the 630 m band. Non-contesting radio amateurs are encouraged to also use the contest-free bands during large international contests.