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Home , Independent sideband, Sideband

Federal Communications Commission § 2.1046

type accepted FM broadcast trans- such as to develop rated peak envelope mitter, provided the transmitter ex- power or carrier power, as appropriate, citer is designed for oper- for the transmitter. ation without mechanical or electrical (1) Single transmitters in alterations to the exciter or other the A3A or A3J emission modes—by transmitter circuits. two tones at of 400 Hz and (j) The addition of TV broadcast 1800 Hz (for 3.0 kHz authorized band- stereophonic generators to a certifi- width), or 500 Hz and 2100 Hz (3.5 kHz cated or formerly type accepted TV authorized ), or 500 Hz and broadcast transmitter or the addition 2400 Hz (for 4.0 kHz authorized band- of FM broadcast stereophonic genera- width), applied simultaneously, the tors to a certificated or formerly type input levels of the tones so adjusted accepted FM broadcast transmitter, that the two principal com- provided the transmitter exciter is de- ponents of the frequency signal signed for oper- produced are equal in magnitude. ation without mechanical or electrical (2) Single sideband transmitters in alterations to the exciter or other the A3H emission mode—by one tone at transmitter circuits. a frequency of 1500 Hz (for 3.0 kHz au- (k) The addition of subscription TV thorized bandwidth), or 1700 Hz (for 3.5 encoding equipment for which the FCC kHz authorized bandwidth), or 1900 Hz has granted advance approval under (for 4.0 kHz authorized bandwidth), the the provisions of § 2.1400 in subpart M level of which is adjusted to produce a and § 73.644(c) of part 73 to a certifi- signal component cated or formerly type accepted trans- equal in magnitude to the magnitude mitter is considered a Class I permis- of the carrier in this mode. sive change. (3) As an alternative to paragraphs (l) Notwithstanding the provisions of (b) (1) and (2) of this section other this section, broadcast licensees or per- tones besides those specified may be mittees are permitted to modify cer- used as modulating frequencies, upon a tificated or formerly type accepted sufficient showing of need. However, equipment pursuant to § 73.1690 of the any tones so chosen must not be har- FCC’s rules. monically related, the third and fifth [63 FR 36600, July 7, 1998, as amended at 66 order products which FR 50840, Oct. 5, 2001] occur must fall within the ¥25 dB step of the emission bandwidth limitation § 2.1046 Measurements required: RF curve, the seventh and ninth order power output. intermodulation product must fall (a) For transmitters other than sin- within the 35 dB step of the referenced gle sideband, and curve and the eleventh and all higher controlled carrier , order products must fall beyond the power output shall be measured at the ¥35 dB step of the referenced curve. RF output terminals when the trans- (4) Independent sideband transmit- mitter is adjusted in accordance with ters having two channels by 1700 Hz the tune-up procedure to give the val- tones applied simultaneously in both ues of current and voltage on the cir- channels, the input levels of the tones cuit elements specified in § 2.1033(c)(8). so adjusted that the two principal fre- The electrical characteristics of the quency components of the radio fre- radio frequency load attached to the quency signal produced are equal in output terminals when this test is magnitude. made shall be stated. (5) Independent sideband transmit- (b) For single sideband, independent ters having more than two channels by sideband, and single channel, con- an appropriate signal or signals applied trolled carrier radiotelephone trans- to all channels simultaneously. The mitters the procedure specified in para- input signal or signals shall simulate graph (a) of this section shall be em- the input signals specified by the man- ployed and, in addition, the trans- ufacturer for normal operation. mitter shall be modulated during the (6) Single-channel controlled-carrier test as follows. In all tests, the input transmitters in the A3 emission mode— level of the modulating signal shall be by a 2500 Hz tone.

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VerDate jul<14>2003 08:21 Dec 10, 2003 Jkt 200191 PO 00000 Frm 00595 Fmt 8010 Sfmt 8010 Y:\SGML\200191T.XXX 200191T § 2.1047 47 CFR Ch. I (10–1–03 Edition)

(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- sponse of the audio modulating circuit. (b) Equipment which employs modula- (2) Single sideband transmitters in tion limiting. A curve or family of A3A or A3J emission modes—when curves showing the percentage of mod- modulated by two tones at frequencies ulation versus the input of 400 Hz and 1800 Hz (for 3.0 kHz au- voltage shall be supplied. The informa- thorized bandwidth), or 500 Hz and 2100 tion submitted shall be sufficient to Hz (for 3.5 kHz authorized bandwidth), show modulation limiting capability or 500 Hz and 2400 Hz (for 4.0 kHz au- throughout the range of modulating thorized bandwidth), applied simulta- frequencies and input modulating sig- neously. The input levels of the tones nal levels employed. shall be so adjusted that the two prin- (c) Single sideband and independent cipal frequency components of the sideband radiotelephone transmitters radio frequency signal produced are which employ a device or circuit to limit equal in magnitude. peak envelope power. A curve showing (3) Single sideband transmitters in the peak envelope power output versus the A3H emission mode—when modu- the modulation input voltage shall be lated by one tone at a frequency of 1500 supplied. The modulating signals shall Hz (for 3.0 kHz authorized bandwidth), be the same in frequency as specified in or 1700 Hz (for 3.5 kHz authorized band- paragraph (c) of § 2.1049 for the occupied width), or 1900 Hz (for 4.0 kHz author- bandwidth tests. ized bandwidth), the level of which is (d) Other types of equipment. A curve adjusted to produce a radio frequency or equivalent data which shows that signal component equal in magnitude the equipment will meet the modula- to the magnitude of the carrier in this tion requirements of the rules under mode. which the equipment is to be licensed. (4) As an alternative to paragraphs [39 FR 5919, Feb. 15, 1974. Redesignated and (c) (2) and (3) of this section, other amended at 63 FR 36599, July 7, 1998] tones besides those specified may be

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