[Code of Federal Regulations]
[Title 47, Volume 4]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR78.103]
[Page 772-773]
TITLE 47--TELECOMMUNICATION
COMMISSION (CONTINUED)
PART 78_CABLE TELEVISION RELAY SERVICE--Table of Contents
Subpart D_Technical Regulations
Sec. 78.103 Emissions and emission limitations.
(a) A CARS station may be authorized to employ any type of emission,
for which there are technical standards incorporated in Subpart D of
this part, suitable for the simultaneous transmission of visual and
aural television signals.
(b) Any emission appearing on a frequency outside of the channel
authorized for a transmitter shall be attenuated below the power of the
emission in accordance with the following schedule:
(1) For stations using FM or double sideband AM transmission:
(i) On any frequency above the upper channel limit or below the
lower channel limit by between zero and 50 percent of the authorized
channel width: At least 25 decibels below the mean power of the
emission;
(ii) On any frequency above the upper channel limit or below the
lower channel limit by more than 50 percent and up to 150 percent of the
authorized channel width: At least 35 decibels below the mean power of
the emission; and
(iii) On any frequency above the upper channel limit or below the
lower channel limit by more than 150 percent of the authorized channel
width: At least 43+10 log10 (power in watts) decibels below the mean
power of the emission.
(2) For CARS stations using vestigial sideband AM transmission: At
least 50 decibels below the peak power of the emission.
(c) For operation in the 17.7.7-19.7 GHz band:
[[Page 773]]
The mean power of any emission shall be attenuated below the mean
output power of the transmitter in accordance with the following
schedule:
(1) When using frequency modulation:
(i) On any frequency removed from the assigned (center) frequency by
more than 50% up to and including 100% of the authorized bandwidth: At
least 25 dB;
(ii) On any frequency removed from the assigned (center) frequency
by more than 100% up to and including 250% of the authorized bandwidth:
At least 35 dB;
(iii) On any frequency removed from the assigned (center) frequency
by more than 250% of the authorized bandwidth: At least 43+10 log 10
(mean output power in watts) dB, or 80 dB, whichever is the lesser
attenuation.
(2) When using digital modulation:
(i) In any 1 MHz band, the center frequency of which is removed from
the assigned frequency by more than 50% up to and including 250% of the
authorized bandwidth: As specified by the following equation but in no
event less than 11 dB.
A = 11 + 0.4 (P - 50) + 10 log10 B
where:
A=Attenuation (in dB) below the mean output power level.
P=Percent removed from the carrier frequency.
B=Authorized bandwidth in MHz.
[Attenuation greater than 56 decibels is not required.]
(ii) In any 4 kHz band, the center frequency of which is removed
from the assigned frequency by more than 250% of the authorized
bandwidth: At least 43=10 log10 (mean output power in watts)
dB, or 80 dB, whichever is the lesser attenuation.
(3) Amplitude Modulation:
For vestigial sideband AM video: On any frequency removed from the
center frequency of the authorized band by more than 50%: at least 50 dB
below peak power of the emission.
(d) In the event that interference to other stations is caused by
emissions outside the authorized channel, the Commission may require
greater attenuation than that specified in paragraph (b) of this
section.
(e) The maximum bandwidth that will be authorized per frequency
assignment is set out in the table that follows. Regardless of the
maximum authorized bandwidth specified for each frequency band, the
Commission reserves the right to issue a license for less than the
maximum bandwidth if it appears that a bandwidth less than the maximum
would be sufficient to support an applicant's intended communications.
------------------------------------------------------------------------
Maximum authorized band-width
Frequency band (MHz) (MHz)
------------------------------------------------------------------------
1,990 to 2,110........................... 17 or 18.\1\
6,425 to 6,525........................... 8 or 25.
6,875 to 7,125........................... 25.
12,700 to 13,250......................... 25.
17,700 to 19,700......................... 80.
------------------------------------------------------------------------
\1\ After a licensee has been relocated in accordance with Sec. 78.40,
the maximum authorized bandwidth in the frequency band 2,025 to 2,110
MHz will be 12.1/12.4 MHz.
[37 FR 3292, Feb. 12, 1972, as amended at 37 FR 15927, Aug. 8, 1972; 38
FR 16648, June 25, 1973; 39 FR 26025, July 16, 1974; 48 FR 50736, Nov.
3, 1983; 49 FR 37779, Sept. 26, 1984; 52 FR 7145, Mar. 9, 1987; 65 FR
48182, Aug. 7, 2000; 68 FR 12776, Mar. 17, 2003]