Chapter IV

Conditions for Radio Equipment Classified by Service or Emission Class and Frequency Band

Section 1   Deleted (Deleted in No. 29 in 1994.)
Article 27-33. Deleted (Deleted in No. 29 in 1994.)
Section 1.2 Radio Equipment of Broadcasting Stations for AM Broadcasting

(Scope of Application)
Article 33.2. The provisions of this Section shall apply to the radio equipment of a broadcasting station for AM broadcasting within the bounds of the output terminal of the microphone amplifier or the sound reproducer to the transmitting antenna (however, the relay line and contact line shall be excluded).
(Modulation Factor)
Article 33.3. The modulator of a transmitter at a broadcasting station for AM broadcasting shall satisfy the conditions defined in the items below:
1) For monophonic broadcasting, the modulator shall ensure amplitude modulation linearity up to at least 95%.
2) For stereophonic broadcasting, the modulator shall ensure amplitude modulation linearity up to at least 95% with the sum of the left and right side signals (which refers to the sum signal prescribed in Article 2 paragraph 2 of the Standard System for Transmission Related to AM Broadcasting (MPT Ordinance No. 4 in 1992; hereinafter referred to as the "Standard System for AM Broadcasting"; this also applies hereafter in this Section).
(Overall Frequency Response Characteristics)
Article 33.4. The overall frequency response characteristics of a transmitter at a broadcasting station for AM broadcasting shall satisfy the conditions defined in the items below:
1) For monophonic broadcasting, the frequency departure in the modulation that uses a modulating frequency in a range of 100 Hz to 7,500 Hz shall be within the range of allowed limits shown in Figure 1-2 in reference to 50% amplitude modulation with a modulating frequency of 400 Hz.
2) For stereophonic broadcasting, the frequency departure in the modulation that uses a modulating frequency in a range of 100 Hz to 7,500 Hz shall be within the range of allowed limits shown in Figure 1-2 in reference to either 50% amplitude modulation with the sum of the identical left and right side signals having a modulating frequency of 400 Hz or 40% amplitude modulation with the left or right side signal having a modulating frequency of 400 Hz.
2   When an identical signal is supplied to both the left and right side signal input terminals of a transmitter, the level difference between the left and right side signals at the output terminals of the transmitter shall be within 1.5 dB for 40% amplitude modulation with the sum signal having any modulating frequency in a range of 200 Hz to 5,000 Hz.
(Overall Distortion Factor)
Article 33.5. The overall distortion factor of a transmitter at a broadcasting station for AM broadcasting shall satisfy the conditions defined in the items below:
1) For monophonic broadcasting, 5% or lower for 80% amplitude modulation with modulating frequencies of 200 Hz, 1,000 Hz, and 5,000 Hz
2) For stereophonic broadcasting, 5% or lower for both 80% amplitude modulation with the sum of the identical left and right side signals having modulating frequencies of 200 Hz, 1,000 Hz, and 5,000 Hz, and 40% amplitude modulation with either the left or right side signal having modulating frequencies of 200 Hz, 1,000 Hz, and 5,000 Hz
(Carrier Amplitude Regulation)
Article 33.6. The carrier frequency current amplitude regulation of a transmitter at a broadcasting station for AM broadcasting shall satisfy the conditions defined in the items below:
1) For monophonic broadcasting, 5% or lower for amplitude modulation with a modulating frequency of 1,000 Hz
2) For stereophonic broadcasting, 5% or lower for amplitude modulation with the sum of the identical left and right side signals having a modulating frequency of 1,000 Hz
(Signal-to-Noise Ratio)
Article 33.7. The signal-to-noise ratio of a transmitter at a broadcasting station for AM broadcasting shall satisfy the conditions defined in the items below:
1) For monophonic broadcasting, 50 dB or higher for 80% amplitude modulation with a modulating frequency of 1,000 Hz
2) For stereophonic broadcasting, 50 dB or higher for 80% amplitude modulation with the sum of the identical left and right side signals having a modulating frequency of 1,000 Hz and 44 dB or higher for 40% amplitude modulation with either the left or right side signal having a modulating frequency of 1,000 Hz
(Channel Separation)
Article 33.8. The channel separation of a transmitter at a broadcasting station for AM broadcasting (which refers to the ratio of the output by which a signal applied to the left or right side signal input terminal of a transmitter appears as the corresponding left or right side signal at the corresponding output terminal of the transmitter versus the output by which the said signal appears as if it were supplied to the other input terminal; this also applies hereafter) shall be 20 dB or higher for 40% amplitude modulation with the left or right side signal having any modulating frequency in a range of 200 Hz to 5,000 Hz.
(Auxiliary Power Supply)
Article 33.9. Broadcasting radio equipment should preferably be equipped with an auxiliary power supply.
Section 1.3 Radio Equipment of Broadcasting Stations for HF Broadcasting

(Scope of Application)
Article 33.10. The provisions of this Section shall apply to the radio equipment of a broadcasting station for HF broadcasting within the bounds of the output terminal of the microphone amplifier or the sound reproducer to the transmitting antenna (however, the relay line and contact line shall be excluded).
(Modulation Method)
Article 33.11. The modulation method of a transmitter at a broadcasting station for HF broadcasting shall be single-sideband amplitude modulation.
(Carrier Frequency)
Article 33.12. The carrier frequency of a transmitter at a broadcasting station for HF broadcasting shall be 2.5 kHz lower than the assigned frequency related to the said transmitter.
(Carrier Power)
Article 33.13. The carrier power of a transmitter at a broadcasting station for HF broadcasting shall be 12 dB ±1 dB lower than the peak envelope power in modulation performed on a saturated level with one modulating frequency.
(Sideband)
Article 33.14. The sideband used by a transmitter at a broadcasting station for HF broadcasting shall be an upper sideband.
2   The unwanted sideband of a transmitter at a broadcasting station for HF broadcasting shall be suppressed by 35 dB or more compared with a signal on the desired sideband as modulated with a modulating frequency of 1,000 Hz at the saturated level of transmission output.
(Overall Frequency Response Characteristics)
Article 33.15. The overall frequency response characteristics of a transmitter at a broadcasting station for HF broadcasting shall be within the range of allowed limits shown in Figure 1-2-2 in terms of a frequency departure in modulation with modulating frequencies of 150 Hz to 4,000 Hz in reference to that in 50% modulation with a modulating frequency of 400 Hz (as compared with modulation using one modulating frequency on the saturated level regarded as being 100%, with 100% sideband output voltage).
(Overall Distortion Factor)
Article 33.16. The overall distortion factor of a transmitter at a broadcasting station for HF broadcasting shall be 5% or lower in 80% modulation with modulating frequencies of 200 Hz, 1,000 Hz, and 3,000 Hz (as compared with modulation using one modulating frequency on the saturated level regarded as being 100%, with 100% sideband output voltage).
(Signal-to-Noise Ratio)
Article 33.17. The signal-to-noise ratio of a transmitter at a broadcasting station for HF broadcasting shall be 50 dB or higher in 80% modulation with a modulating frequency of 1,000 Hz (as compared with modulation using one modulating frequency on the saturated level regarded as being 100%, with 100% sideband output voltage).
(Auxiliary Power Supply)
Article 33.18. The provisions of Article 33.9 shall apply mutatis mutandis to the broadcasting radio equipment of a broadcasting station for HF broadcasting.
(Special Exceptions of Transmitters)
Article 33.19. Notwithstanding the provisions of Articles 33.11 to 33.17, a transmitter at a broadcasting station for HF broadcasting using class A3E emissions shall satisfy the technical conditions announced separately (*) by the Minister of Public Management Home Affair, Posts and Telecommunications.
2   Notwithstanding the provisions of Article 33.13, Article 33.14 paragraph 2, and Article 33.16, a transmitter at a broadcasting station for HF broadcasting using class H3E emissions shall satisfy the technical conditions announced separately (*) by the Minister of Public Management, Home Affairs, Posts and Telecommunications.
(Announcement: * in No. 243 in 1994)