Federal Communications Commission § 2.1049

curve, the seventh and ninth order voltage shall be supplied. The informa- intermodulation product must fall tion submitted shall be sufficient to within the 35 dB step of the referenced show limiting capability curve and the eleventh and all higher throughout the range of modulating order products must fall beyond the frequencies and input modulating sig- ¥35 dB step of the referenced curve. nal levels employed. (4) Independent transmit- (c) Single sideband and independent ters having two channels by 1700 Hz sideband transmitters tones applied simultaneously in both which employ a device or circuit to limit channels, the input levels of the tones peak envelope power. A curve showing so adjusted that the two principal fre- the peak envelope power output versus quency components of the radio fre- the modulation input voltage shall be quency signal produced are equal in supplied. The modulating signals shall magnitude. be the same in frequency as specified in (5) Independent sideband transmit- paragraph (c) of § 2.1049 for the occupied ters having more than two channels by tests. an appropriate signal or signals applied (d) Other types of equipment. A curve to all channels simultaneously. The or equivalent data which shows that input signal or signals shall simulate the equipment will meet the modula- the input signals specified by the man- tion requirements of the rules under ufacturer for normal operation. which the equipment is to be licensed. (6) Single-channel controlled-carrier [39 FR 5919, Feb. 15, 1974. Redesignated and transmitters in the A3 emission mode— amended at 63 FR 36599, July 7, 1998] by a 2500 Hz tone. (c) For measurements conducted pur- § 2.1049 Measurements required: Occu- suant to paragraphs (a) and (b) of this pied bandwidth. section, all calculations and methods The occupied bandwidth, that is the used by the applicant for determining frequency bandwidth such that, below carrier power or peak envelope power, its lower and above its upper frequency as appropriate, on the basis of meas- limits, the mean powers radiated are ured power in the radio frequency load each equal to 0.5 percent of the total attached to the transmitter output ter- mean power radiated by a given emis- minals shall be shown. Under the test sion shall be measured under the fol- conditions specified, no components of lowing conditions as applicable: the emission spectrum shall exceed the (a) Radiotelegraph transmitters for limits specified in the applicable rule manual operation when keyed at 16 parts as necessary for meeting occu- dots per second. pied bandwidth or emission limita- (b) Other keyed transmitters—when tions. keyed at the maximum machine speed. [39 FR 5919, Feb. 15, 1974. Redesignated and (c) Radiotelephone transmitters amended at 63 FR 36599, July 7, 1998] equipped with a device to limit modu- lation or peak envelope power shall be § 2.1047 Measurements required: Mod- modulated as follows. For single side- ulation characteristics. band and independent sideband trans- (a) Voice modulated communication mitters, the input level of the modu- equipment. A curve or equivalent data lating signal shall be 10 dB greater showing the frequency response of the than that necessary to produce rated audio modulating circuit over a range peak envelope power. of 100 to 5000 Hz shall be submitted. For (1) Other than single sideband or equipment required to have an audio independent sideband transmitters— low-pass filter, a curve showing the fre- when modulated by a 2500 Hz tone at an quency response of the filter, or of all input level 16 dB greater than that nec- circuitry installed between the modu- essary to produce 50 percent modula- lation limiter and the modulated stage tion. The input level shall be estab- shall be submitted. lished at the frequency of maximum re- (b) Equipment which employs modula- sponse of the audio modulating circuit. tion limiting. A curve or family of (2) Single sideband transmitters in curves showing the percentage of mod- A3A or A3J emission modes—when ulation versus the modulation input modulated by two tones at frequencies

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of 400 Hz and 1800 Hz (for 3.0 kHz au- ulation is unattainable, the highest thorized bandwidth), or 500 Hz and 2100 percentage modulation shall be used. Hz (for 3.5 kHz authorized bandwidth), (2) Single sideband transmitters in or 500 Hz and 2400 Hz (for 4.0 kHz au- A3A or A3J emission modes—when thorized bandwidth), applied simulta- modulated by two tones at frequencies neously. The input levels of the tones of 400 Hz and 1800 Hz (for 3.0 kHz au- shall be so adjusted that the two prin- thorized bandwidth), or 500 Hz and 2100 cipal frequency components of the Hz (for 3.5 kHz authorized bandwidth), radio frequency signal produced are or 500 Hz and 2400 Hz (for 4.0 kHz au- equal in magnitude. thorized bandwidth), applied simulta- (3) Single sideband transmitters in neously. The input levels of the tones the A3H emission mode—when modu- shall be so adjusted that the two prin- lated by one tone at a frequency of 1500 cipal frequency components of the Hz (for 3.0 kHz authorized bandwidth), radio frequency signal produced are or 1700 Hz (for 3.5 kHz authorized band- equal in magnitude. width), or 1900 Hz (for 4.0 kHz author- (3) Single sideband transmitters in ized bandwidth), the level of which is the A3H emission mode—when modu- adjusted to produce a radio frequency lated by one tone at a frequency of 1500 signal component equal in magnitude Hz (for 3.0 kHz authorized bandwidth), to the magnitude of the carrier in this or 1700 Hz (for 3.5 kHz authorized band- mode. width), or 1900 Hz (for 4.0 kHz author- (4) As an alternative to paragraphs ized bandwidth), the level of which is (c) (2) and (3) of this section, other adjusted to produce a radio frequency tones besides those specified may be signal component equal in magnitude used as modulating frequencies, upon a to the magnitude of the carrier in this sufficient showing of need. However, mode. any tones so chosen must not be har- (4) As an alternative to paragraphs (d) (2) and (3) of this section, other monically related, the third and fifth tones besides those specified may be order intermodulation products which used as modulating frequencies, upon a occur must fall within the ¥25 dB step sufficient showing of need. However of the emission bandwidth limitation any tones so chosen must not be har- curve, the seventh and ninth order monically related, the third and fifth products must fall within the ¥35 dB order intermodulation products which step of the referenced curve and the occur must fall within the ¥25 dB step eleventh and all higher order products of the emission bandwidth limitation must fall beyond the ¥35 dB step of the curve, the seventh and ninth order referenced curve. products must fall within the ¥35 dB (5) Independent sideband transmit- step of the referenced curve and the ters having two channels—when modu- eleventh and all higher order products lated by 1700 Hz tones applied simulta- must fall beyond the ¥35 dB step of the neously to both channels. The input referenced curve. levels of the tones shall be so adjusted (5) Independent sideband transmit- that the two principal frequency com- ters having two channels—when modu- ponents of the radio frequency signal lated by 1700 Hz tones applied simulta- produced are equal in magnitude. neously to both channels. The input (d) Radiotelephone transmitters levels of the tones shall be so adjusted without a device to limit modulation that the two principal frequency com- or peak envelope power shall be modu- ponents of the radio frequency signal lated as follows. For single sideband produced are equal in magnitude. and independent sideband transmitters, (e) Transmitters for use in the Radio the input level of the modulating sig- Broadcast Services: nal should be that necessary to produce (1) AM broadcast transmitters for rated peak envelope power. monaural operation—when amplitude (1) Other than single sideband or modulated 85% by a 7,500 Hz input sig- independent sideband transmitters— nal. when modulated by a 2500 Hz tone of (2) AM broadcast stereophonic oper- sufficient level to produce at least 85 ation—when the transmitter operated percent modulation. If 85 percent mod- under any stereophonic modulation

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condition not exceeding 100% on nega- provided. The signals to the main chan- tive peaks and tested under the condi- nel and the stereophonic subchannel tions specified in § 73.128 in part 73 of must be representative of the system the FCC rules for AM broadcast sta- being tested and when combined with tions. any pilot subcarrier(s) or other auxil- (3) FM broadcast transmitter not iary subcarriers shall result in 85% de- used for multiplex operation—when viation of the maximum specified aural modulated 85 percent by a 15 kHz input carrier deviation. signal. (f) Transmitters for which peak fre- (4) FM broadcast transmitters for quency deviation (D) is determined in multiplex operation under Subsidiary accordance with § 2.202(f), and in which Communication Authorization (SCA)— the modulating baseband comprises when carrier is modulated 70 percent more than 3 independent speech chan- by a 15 kHz main channel input signal, nels—when modulated by a test signal and modulated an additional 15 percent determined in accordance with the fol- simultaneously by a 67 kHz subcarrier lowing: (unmodulated). (5) FM broadcast transmitter for (1) A modulation reference level is es- stereophonic operation—when modu- tablished for the characteristic lated by a 15 kHz input signal to the baseband frequency. (Modulation ref- main channel, a 15 kHz input signal to erence level is defined as the average the stereophonic subchannel, and the power level of a sinusoidal test signal pilot subcarrier simultaneously. The delivered to the modulator input which input signals to the main channel and provides the specified value of per- stereophonic subchannel each shall channel deviation.) produce 38 percent modulation of the (2) Modulation reference level being carrier. The pilot subcarrier should established, the total rms deviation of produce 9 percent modulation of the the transmitter is measured when a carrier. test signal consisting of a band of ran- (6) Television broadcast monaural dom noise extending from below 20 kHz transmitters—when modulated 85% by to the highest frequency in the a 15 kHz input signal. baseband, is applied to the modulator (7) Television broadcast stereophonic input through any preemphasis net- sound transmitters—when the trans- works used in normal service. The av- mitter is modulated with a 15 kHz erage power level of the test signal input signal to the main channel and shall exceed the modulation reference the stereophonic subchannel, any pilot level by the number of decibels deter- subcarrier(s) and any unmodulated mined using the appropriate formula in auxiliary subcarrier(s) which may be the following table:

Number of message circuits that Number of dB by which the average power (Pavg) level test sig- modulate the transmitter nal shall exceed the modulation reference level Limits of Pavg (dBm0)

More than 3, but less than 12 ...... To be specified by the equipment manufacturer subject to FCC approval. At least 12, but less than 60 ...... X+2 log10 Nc ...... X: ¥2 to +2.6 At least 60, but less than 240 ...... X+4 log10 Nc ...... X: ¥5.6 to ¥1.0 240 or more ...... X+10 log10 Nc ...... X: ¥19.6 to ¥15.0

Where X represents the average power in a message circuit in dBm0; Nc is the number of circuits in the multiplexed message load. Pavg shall be selected by the transmitter manufacturer and included with the technical data submitted with the application for type acceptance. (See § 2.202(e) in this chapter.)

(g) Transmitters in which the modu- mitter is intended. If specific modula- lating baseband comprises not more tion levels are not set forth in the than three independent channels— rules, the tests should provide the when modulated by the full com- manufacturer’s maximum rated condi- plement of signals for which the trans- tion. mitter is rated. The level of modula- (h) Transmitters employing digital tion for each channel should be set to modulation techniques—when modu- that prescribed in rule parts applicable lated by an input signal such that its to the services for which the trans- amplitude and symbol rate represent

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the maximum rated conditions under trolled carrier transmitters shall be which the equipment will be operated. modulated under the conditions speci- The signal shall be applied through any fied in paragraph (c) of § 2.1049, as ap- filter networks, pseudo-random genera- propriate. For equipment operating on tors or other devices required in nor- frequencies below 890 MHz, an open mal service. Additionally, the occupied field test is normally required, with bandwidth shall be shown for operation the measuring instrument antenna lo- with any devices used for modifying cated in the far-field at all test fre- the spectrum when such devices are op- quencies. In the event it is either im- tional at the discretion of the user. practical or impossible to make open (i) Transmitters designed for other field measurements (e.g. a broadcast types of modulation—when modulated transmitter installed in a building) by an appropriate signal of sufficient measurements will be accepted of the amplitude to be representative of the equipment as installed. Such measure- type of service in which used. A de- ments must be accompanied by a de- scription of the input signal should be scription of the site where the meas- supplied. urements were made showing the loca- (Secs. 4, 303, 307, 48 Stat., as amended, 1066, tion of any possible source of reflec- 1082, 1083; 47 U.S.C. 154, 303, 307) tions which might distort the field strength measurements. Information [39 FR 5919, Feb. 15, 1974, as amended at 39 FR 35664, Oct. 3, 1974; 47 FR 13164, Mar. 29, submitted shall include the relative ra- 1982; 48 FR 16493, Apr. 18, 1983; 49 FR 18105, diated power of each spurious emission Apr. 27, 1984. Redesignated at 63 FR 36599, with reference to the rated power out- July 7, 1998] put of the transmitter, assuming all emissions are radiated from halfwave § 2.1051 Measurements required: Spu- dipole antennas. rious emissions at antenna termi- nals. (b) The measurements specified in paragraph (a) of this section shall be The radio frequency voltage or pow- made for the following equipment: ers generated within the equipment (1) Those in which the spurious emis- and appearing on a spurious frequency sions are required to be 60 dB or more shall be checked at the equipment out- below the mean power of the trans- put terminals when properly loaded mitter. with a suitable artificial antenna. (2) All equipment operating on fre- Curves or equivalent data shall show quencies higher than 25 MHz. the magnitude of each harmonic and (3) All equipment where the antenna other spurious emission that can be de- is an integral part of, and attached di- tected when the equipment is operated rectly to the transmitter. under the conditions specified in § 2.1049 as appropriate. The magnitude (4) Other types of equipment as re- of spurious emissions which are attenu- quired, when deemed necessary by the ated more than 20 dB below the permis- Commission. sible value need not be specified. [39 FR 5919, Feb. 15, 1974. Redesignated and amended at 63 FR 36599, July 7, 1998] [39 FR 5919, Feb. 15, 1974. Redesignated and amended at 63 FR 36599, July 7, 1998] § 2.1055 Measurements required: Fre- § 2.1053 Measurements required: Field quency stability. strength of spurious radiation. (a) The frequency stability shall be (a) Measurements shall be made to measured with variation of ambient detect spurious emissions that may be temperature as follows: radiated directly from the cabinet, (1) From ¥30° to +50° centigrade for control circuits, power leads, or inter- all equipment except that specified in mediate circuit elements under normal paragraphs (a) (2) and (3) of this sec- conditions of installation and oper- tion. ation. Curves or equivalent data shall (2) From ¥20° to +50° centigrade for be supplied showing the magnitude of equipment to be licensed for use in the each harmonic and other spurious Maritime Services under part 80 of this emission. For this test, single side- chapter, except for Class A, B, and S band, independent sideband, and con- Emergency Position Indicating

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