§ 74.861   Technical requirements.

   (a) Transmitter power is the power at the transmitter output terminals and
   delivered  to  the  antenna,  antenna  transmission line, or any other
   impedance-matched, radio frequency load. For the purpose of this subpart,
   the transmitter power is the carrier power.

   (b) Each authorization for a new low power auxiliary station shall require
   the use of certificated equipment. Such equipment shall be operated in
   accordance with the emission specifications included in the certification
   grant and as prescribed in paragraphs (c) through (e) of this section.

   (c) Low power auxiliary transmitters not required to operate on specific
   carrier  frequencies  shall operate sufficiently within the authorized
   frequency band edges to insure the emission bandwidth falls entirely within
   the authorized band.

   (d) For low power auxiliary stations operating in the bands other than those
   allocated for TV broadcasting, the following technical requirements are
   imposed.

   (1)  The maximum transmitter power which will be authorized is 1 watt.
   Licensees may accept the manufacturer's power rating; however, it is the
   licensee's responsibility to observe specified power limits.

   (2)  If  a  low  power auxiliary station employs amplitude modulation,
   modulation shall not exceed 100 percent on positive or negative peaks.

   (3) The occupied bandwidth shall not be greater than that necessary for
   satisfactory transmission and, in any event, an emission appearing on any
   discrete frequency outside the authorized band shall be attenuated, at
   least, 43 + 10 log10 (mean output power, in watts) dB below the mean output
   power of the transmitting unit.

   (e) For low power auxiliary stations operating in the bands allocated for TV
   broadcasting, the following technical requirements apply:

   (1) The power of the measured unmodulated carrier power at the output of the
   transmitter  power  amplifier (antenna input power) may not exceed the
   following:

   (i) 54-72, 76-88, and 174-216 MHz bands—50 mW

   (ii) 470-608 and 614-698 MHz bands—250 mW

   (2) Transmitters may be either crystal controlled or frequency synthesized.

   (3) Any form of modulation may be used. A maximum deviation of ±75 kHz is
   permitted when frequency modulation is employed.

   (4) The frequency tolerance of the transmitter shall be 0.005 percent.

   (5) The operating bandwidth shall not exceed 200 kHz.

   (6) The mean power of emissions shall be attenuated below the mean output
   power of the transmitter in accordance with the following schedule:

   (i) On any frequency removed from the operating frequency by more than 50
   percent up to and including 100 percent of the authorized bandwidth: at
   least 25 dB;

   (ii) On any frequency removed from the operating frequency by more than 100
   percent up to and including 250 percent of the authorized bandwidth: at
   least 35 dB;

   (iii) On any frequency removed from the operating frequency by more than 250
   percent of the authorized bandwidth: at least 43 + 10log10 (mean output
   power in watts) dB.

   (f) Unusual transmitting antennas or antenna elevations shall not be used to
   deliberately extend the range of low power auxiliary stations beyond the
   limited areas defined in § 74.831.

   (g)  Low power auxiliary stations shall be operated so that no harmful
   interference is caused to any other class of station operating in accordance
   with Commission's rules and regulations and with the Table of Frequency
   Allocations in part 2 thereof.

   (h) In the event a station's emissions outside its authorized frequency band
   causes harmful interference, the Commission may, at its discretion, require
   the licensee to take such further steps as may be necessary to eliminate the
   interference.

   (Sec. 5, 48 Stat. 1068; 47 U.S.C. 155)

   [ 43 FR 13576 , Mar. 31, 1978, as amended at  52 FR 2535 , Jan. 23, 1987;  63 FR 36605 , July 7, 1998;  75 FR 3639 , Jan. 22, 2010]

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