Sec. 74.901  Definitions.

    Attended operation. Operation of a station by a designated person on 
duty

[[Page 451]]

at the place where the transmitting apparatus is located with the 
transmitter in the person's plain view.
    Equivalent Isotropically Radiated Power (EIRP). The product of the 
power supplied to the antenna and the antenna gain in a given direction 
relative to an isotropic antenna radiator. This product may be expressed 
in watts or dB above 1 watt (dBW).
    Instructional television fixed station. A fixed station operated by 
an educational organization and used primarily for the transmission of 
visual and aural instructional, cultural, and other types of educational 
material to one or more fixed receiving locations.
    ITFS response station. A fixed station operated at an authorized 
location to provide communication by voice and/or data signals to an 
associated instructional television fixed station.
    Main channel: The main channel is that portion of each authorized 
channel used for the transmission of visual and aural information as set 
forth in Sec. 73.682 of this Chapter and Sec. 74.938 of this subpart.
    Point-to-point ITFS station. An ITFS station that transmits a highly 
directional signal from a fixed transmitter location to a fixed receive 
location.
    Remote control. Operation of a station by a designated person at a 
control position from which the transmitter is not visible but where 
suitable control and telemetering circuits are provided which allow the 
performance of the essential functions that could be performed at the 
transmitter.
    Studio to transmitter link (STL). A directional path used to 
transmit a signal from a station's studio to its transmitter.
    Subsidiary channel: A subsidiary channel is any portion of an 
authorized channel not used for main channel transmissions.
    Temporary fixed ITFS station. An ITFS station used for the 
transmission of material from temporary unspecified points to an ITFS 
station.
    Unattended operation. Operation of a station by automatic means 
whereby the transmitter is turned on and off and performs its functions 
without attention by a designated person.

[ 28 FR 13731 , Dec. 14, 1963, as amended at  35 FR 4705 , Mar. 18, 1970;  48 FR 33901 , July 26, 1983;  49 FR 32596 , Aug. 15, 1984;  55 FR 46013 , Oct. 
31, 1990;  60 FR 55483 , Nov. 1, 1995]