FCC 87.139 Revised as of October 1, 2006
Goto Year:2005 |
2007
Sec. 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 Sec. 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
------------------------------------------------------------------------
\1\ These 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.
\2\ Attenuation measured within the transmit band excludes the band
±35 kHz of the carrier frequency.
\3\ This level is not applicable for intermodulation products.
\4\ The 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:
------------------------------------------------------------------------
Attenuation
Frequency Offset (normalized to SR) (dB)
------------------------------------------------------------------------
±0.75 x SR.......................................... 0
±1.40 x SR.......................................... 20
±2.95 x 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.
[ 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]
CiteFind - See documents on FCC website that
cite this rule
Want to support this service?
Thanks!
Report errors in
this rule. Since these rules are converted to HTML by machine, it's possible errors have been made. Please
help us improve these rules by clicking the Report FCC Rule Errors link to report an error.