Goto Section: 87.137 | 87.141 | Table of Contents
FCC 87.139
Revised as of October 1, 2011
Goto Year:2010 |
2012
§ 87.139 Emission limitations.
(a) Except for ELTs and when using single sideband (R3E, H3E, J3E), or
frequency modulation (F9) or digital modulation (F9Y) for telemetry or
telecommand in the frequency bands 1435-1535 MHz and 2310-2390 MHz or
digital modulation (G7D) for differential GPS, the mean power of any
emission must be attenuated below the mean power of the transmitter
(pY) as follows:
(1) When the frequency is removed from the assigned frequency by more
than 50 percent up to and including 100 percent of the authorized
bandwidth the attenuation must be at least 25 dB;
(2) When the frequency is removed from the assigned frequency by more
than 100 percent up to and including 250 percent of the authorized
bandwidth the attenuation must be at least 35 dB.
(3) When the frequency is removed from the assigned frequency by more
than 250 percent of the authorized bandwidth the attenuation for
aircraft station transmitters must be at least 40 dB; and the
attenuation for aeronautical station transmitters must be at least 43 +
10 log[10]pY dB.
(b) For aircraft station transmitters and for aeronautical station
transmitters first installed before February 1, 1983, and using H2B,
H3E, J3E, J7B or J9W, the mean power of any emissions must be
attenuated below the mean power of the transmitter (pY) as follows:
(1) When the frequency is removed from the assigned frequency by more
than 50 percent up to and including 150 percent of the authorized
bandwidth of 4.0 kHz, the attenuation must be at least 25 dB.
(2) When the frequency is removed from the assigned frequency by more
than 150 percent up to and including 250 percent of the authorized
bandwidth of 4.0 kHz, the attenuation must be at least 35 dB.
(3) When the frequency is removed from the assigned frequency by more
than 250 percent of the authorized bandwidth of 4.0 kHz for aircraft
station transmitters the attenuation must be at least 40 dB; and for
aeronautical station transmitters the attenuation must be at least 43 +
10 log[10]pY dB.
(c) For aircraft station transmitters first installed after February 1,
1983, and for aeronautical station transmitters in use after February
1, 1983, and using H2B, H3E, J3E, J7B or J9W, the peak envelope power
of any emissions must be attenuated below the peak envelope power of
the transmitter (pX) as follows:
(1) When the frequency is removed from the assigned frequency by more
than 50 percent up to and including 150 percent of the authorized
bandwidth of 3.0 kHz, the attenuation must be at least 30 dB.
(2) When the frequency is removed from the assigned frequency by more
than 150 percent up to and including 250 percent of the authorized
bandwidth of 3.0 kHz, the attenuation must be at least 38 dB.
(3) When the frequency is removed from the assigned frequency by more
than 250 percent of the authorized bandwidth of 3.0 kHz for aircraft
transmitters the attenuation must be at least 43 dB. For aeronautical
station transmitters with transmitter power up to and including 50
watts the attenuation must be at least 43 + 10 log[10]pX dB and with
transmitter power more than 50 watts the attenuation must be at least
60 dB.
(d) Except for telemetry in the 1435-1535 MHz band, when the frequency
is removed from the assigned frequency by more than 250 percent of the
authorized bandwidth for aircraft stations above 30 MHz and all ground
stations the attenuation must be at least 43+10 log[10]pY dB.
(e) When using frequency modulation or digital modulation for telemetry
or telecommand in the 1435-1535 MHz and 2310-2390 MHz frequency bands
with an authorized bandwidth equal to or less than 1 MHz the emissions
must be attenuated as follows:
(1) On any frequency removed from the assigned frequency by more than
100 percent of the authorized bandwidth up to and including 100 percent
plus 0.5 MHz, the attenuation must be at least 60 dB, when measured in
a 3.0 kHz bandwidth. This signal need not be attenuated more than 25 dB
below 1 milliwatt.
(2) On any frequency removed from the assigned frequency by more than
100 percent of the authorized bandwidth plus 0.5 MHz, the attenuation
must be at least 55 + 10 log[10]pY dB when measured in a 3.0 kHz
bandwidth.
(f) When using frequency modulation or digital modulation for telemetry
or telecommand in the 1435-1535 MHz or 2310-2390 MHz frequency bands
with an authorized bandwidth greater than 1 MHz, the emissions must be
attenuated as follows:
(1) On any frequency removed from the assigned frequency by more than
50 percent of the authorized bandwidth plus 0.5 MHz up to and including
50 percent of the authorized bandwidth plus 1.0 MHz, the attenuation
must be 60 dB, when measured in a 3.0 kHz bandwidth. The signal need
not be attenuated more than 25 dB below 1 milliwatt.
(2) On any frequency removed from the assigned frequency by more than
50 percent of the authorized bandwidth plus 1.0 MHz, the attenuation
must be at least 55 + 10 log[10]pY dB, when measured in a 3.0 kHz
bandwidth.
(g) The requirements of paragraphs (e) and (f) of this section apply to
transmitters approved after January 1, 1977, and to all transmitters
first installed after January 1, 1983.
(h) For ELTs operating on 121.500 MHz, 243.000 MHz and 406.0-406.1 MHz
the mean power of any emission must be attenuated below the mean power
of the transmitter (pY) as follows:
(1) When the frequency is moved from the assigned frequency by more
than 50 percent up to and including 100 percent of the authorized
bandwidth the attenuation must be at least 25 dB;
(2) When the frequency is removed from the assigned frequency by more
than 100 percent of the authorized bandwidth the attenuation must be at
least 30 dB.
(i) In case of conflict with other provisions of § 87.139, the
provisions of this paragraph shall govern for aircraft earth stations.
When using G1D, G1E, or G1W emissions in the 1646.5-1660.5 MHz
frequency band, the emissions must be attenuated as shown below.
(1) At rated output power, while transmitting a modulated single
carrier, the composite spurious and noise output shall be attenuated by
at least:
Frequency (MHz) Attenuation (dB)^1
0.01 to 1525 -135 dB/4 kHz
1525 to 1559 -203 dB/4 kHz
1559 to 1585 -155 dB/MHz
1585 to 1605 -143 dB/MHz
1605 to 1610 -117 dB/MHz
1610 to 1610.6 -95 dB/MHz
1610.6 to 1613.8 -80 dBW/MHz^3
1613.8 to 1614 -95 dB/MHz
1614 to 1626.5 -70 dB/4 kHz
1626.5 to 1660 -70 dB/4 kHz^2,3,4
1660 to 1670 -49.5 dBW/20 kHz^2,3,4
1670 to 1735 -60 dB/4 kHz
1735 to 12000 -105 dB/4 kHz
12000 to 18000 -70 dB/4 kHz
^1These values are expressed in dB referenced to the carrier for the
bandwidth indicated, and relative to the maximum emission envelope
level, except where the attenuation is shown in dBW, the attenuation is
expressed in terms of absolute power referenced to the bandwidth
indicated.
^2Attenuation measured within the transmit band excludes the band +-35
kHz of the carrier frequency.
^3This level is not applicable for intermodulation products.
^4The upper limit for the excess power for any narrow-band spurious
emission (excluding intermodulation products within a 30 kHz
measurement bandwidth) shall be 10 dB above the power limit in this
table.
(2) The transmitter emission limit is a function of the modulation type
and symbol rate (SR). Symbol Rate is expressed in symbols per second.
(3) While transmitting a single modulated signal at the rated output
power of the transmitter, the emissions must be attenuated below the
maximum emission level by at least:
Frequency Offset (normalized to SR) Attenuation (dB)
+-0.75 * SR 0
+-1.40 * SR 20
+-2.95 * SR 40
Where:
SR = Symbol Rate,
SR = 1 * channel rate for BPSK,
SR = 0.5 * channel rate for QPSK.
The mask shall be defined by drawing straight lines through the above
points.
(j) When using G7D for differential GPS in the 112-118 MHz band, the
amount of power during transmission under all operating conditions when
measured over a 25 kHz bandwidth centered on either of the second
adjacent channels shall not exceed -25 dBm and shall decrease 5 dB per
octave until -52 dBm.
(k) For VHF aeronautical stations and aircraft stations operating with
G1D or G7D emissions:
(1) The amount of power measured across either first adjacent 25 kHz
channel shall not exceed 2 dBm.
(2) For stations first installed before January 1, 2002, the amount of
power measured across either second adjacent channel shall be less than
-25 dBm and the power measured in any other adjacent 25 kHz channels
shall monotonically decrease at a rate of at least 5 dB per octave to a
maximum value of -52 dBm. For stations first installed on or after
January 1, 2002,
(i) The amount of power measured across either second adjacent 25 kHz
channel shall be less than -28 dBm;
(ii) The amount of power measured across either fourth adjacent 25 kHz
channel shall be less than -38 dBm; and
(iii) From thereon the power measured in any other adjacent 25 kHz
channel shall monotonically decrease at a rate of at least 5 dB per
octave to a maximum value of -53 dBm.
(3) The amount of power measured over a 16 kHz channel bandwidth
centered on the first adjacent 25 kHz channel shall not exceed -18 dBm.
(l)(1) For Universal Access Transceiver transmitters, the average
emissions measured in a 100 kHz bandwidth must be attenuated below the
maximum emission level contained within the authorized bandwidth by at
least:
Frequency (MHz) Attenuation
(dB)
+/ -0.5 0
+/ -1.0 18
+/ -2.25 50
+/ -3.25 60
(2) Universal Access Transceiver transmitters with an output power of 5
Watts or more must limit their emissions by at least 43 + 10 log (P) dB
on any frequency removed from the assigned frequency by more than 250%
of the authorized bandwidth. Those emissions shall be measured with a
bandwidth of 100 kHz. P in the above equation is the average
transmitter power measured within the occupied bandwidth in Watts.
(3) Universal Access Transceiver transmitters with less than 5 Watts of
output power must limit their emissions by at least 40 dB relative to
the carrier peak on any frequency removed from the assigned frequency
by more than 250% of the authorized bandwidth. Those emissions shall be
measured with a bandwidth of 100 kHz.
[ 53 FR 28940 , Aug. 1, 1988, as amended at 56 FR 11518 , Mar. 19, 1991;
57 FR 45749 , Oct. 5, 1992; 58 FR 30127 , May 26, 1993; 58 FR 67695 , Dec.
22, 1993; 59 FR 35269 , July 11, 1994; 63 FR 36607 , July 7, 1998; 64 FR 27475 , May 20, 1999; 66 FR 26799 , May 15, 2001; 67 FR 4676 , Jan. 31,
2002; 69 FR 32881 , June 14, 2004; 71 FR 70676 , Dec. 6, 2006]
Goto Section: 87.137 | 87.141
Goto Year: 2010 |
2012
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