RSS-181 Issue 1 April 1, 1971 Spectrum Management Radio Standards Specification Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band Aussi disponible en français - CNR-181 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 1. Intent 1.1 This specification (amended from time to time) sets forth the minimum performance standards required for the type-approval of radio-telephone non-multiplex transmitters and receivers described by the above specification title. Submission for approval shall be made under one or more of the following categories: L - Transmitters and receivers for use in coast stations C - Transmitters not less than 100 watts PEP and receivers for use in compulsorily-fitted ship stations. V - Transmitters not less than 30 watts PEP and receivers for use in voluntarily- fitted ship stations. Y - Transmitters less than 30 watts PEP and receivers for use in voluntarily-fitted ship stations. Note: These letters will be suffixed to the type-approval number according to the category or categories under which the equipment is approved. 1.2 Transmitters and receivers type-approved under this Specification are technically suitable for licensing in accordance with the provisions of the General Radio Regulations, Part II. 2. General 2.1 Those seeking approval of equipment under this Specification shall satisfy the Department at their own expense that the equipment actually meets this Specification. 2.2 Notwithstanding the fact that a particular piece of equipment meets this Specification, the Department reserves the right to require that adjustments be made to that equipment wherever it causes interference within the meaning of the Radio Act. 2.3 The Department reserves the right to revise this Specification. 3. Related Specifications and Procedures 3.1 Radio Standards Procedure 100 - Procedure for obtaining type-approval of equipment. 1 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 3.2 Radio Standards Specification 111 - Installation of Maritime Mobile Radiotelephone Equipment for Ship Stations operating in the Medium and High Frequency Bands. 4. Equipment Requirements 4.1 Sideband Emitted - The upper sideband only shall be emitted. 4.2 Power Output Limitation 4.2.1 The transmitter shall automatically limit the maximum output of the transmitter to a level not exceeding 1 dB of the manufacturer’s rated peak envelope power (PEP). 4.2.2 Limiting action shall be accomplished in such a manner that when operating in the A3H mode the carrier is not limited in a manner which reduces it below -6 dB relative to the emitted PEP. 4.3 Construction - The equipment construction shall be such as to minimize cabinet radiation. 4.4 Speech Clarifier - In the case when a speech clarifier is provided; the operation of this control shall not change the transmitter carrier frequency. 4.5 Equipment Identification - The following information shall be permanently displayed on each transmitter, receiver or inseparable combination thereof: (a) Type Approval number (b) Serial number of equipment (c) Manufacturer’s name (d) Model identification 5. Standard Test Conditions (Transmitter) 5.1 Definition - Standard test conditions are those conditions which shall apply to the transmitter while it is being tested for minimum requirements. These conditions apply unless otherwise specified. 5.2 Test Voltage - The test voltage shall be the voltage applied to the input terminals on the equipment. It shall be within 2% of the value stated by the manufacturer to be the working voltage. 5.3 Temperature - Temperature shall be 25°c ± 5°C. 2 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 5.4 Two-frequency Test Signal - The two-frequency test signal shall consist of two sinusoidal signals, the frequencies of which are 850 Hz ± 5% and 1950 Hz ± 5%, and the levels of which, when simultaneously applied to the audio input terminals of the transmitter, result in equal amplitude radio frequency output signals. 5.5 Test Modulation - The test modulation shall consist of the standard two-frequency test signal applied at a level sufficient to obtain rated PEP. (See Paragraph 6.1.3) 5.6 Peak Envelope Power (PEP) - PEP is the average power developed by the transmitter during one radio frequency cycle at the highest crest of the modulation envelope. 5.7 Maximum R.f. Power Output Rating (M.P.O.R.) - The maximum power output rating which may be specified by the manufacturer is that peak envelope power (PEP) developed by the transmitter such that the highest power odd-order difference frequency intermodulation product is “X” dB below the rated PEP or when the final amplifier dissipation rating is reached, whichever occurs at the lower power output. The symbol “X” shall have the following numerical values: Maximum RF Power Output M.P.O.R. X Up to 100 watts 32 dB MPOR 100 watts up to 5600 watts 32 + 8 log10 100 5600 watts and over 46 dB 5.8 Test Frequencies - Except where otherwise specified all tests shall be made using at least two frequencies, one near the high end and one near the low end of the frequency range for which the transmitter is to be type-approved. If the transmitter operates in the frequency bands between 1605-2650 kHz, one of the test frequencies shelf be 2182 kHz. 5.9 Output Termination - The standard output termination shall consist of a nominal 50 ohm restive load. Where other output terminations are used for the tests, they shall be specified in the test report and shall be within the impedance range of the equipment as stated by the manufacturer. 3 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 5.10 Test Receiver - The standard test receiver shall have an audio response characteristic within ± 2dB of the reference level at lO0O Hz between 50 and 6000 Hz. 5.11 Frequency Analyzer - The resolution and accuracy of the frequency analyzer used shall be stated in the test report. 5.12 Assigned Frequency - The assigned frequency is 1400 Hz higher than the carrier frequency. 6. Minimum Standard (Transmitters) 6.1 RATED PEP 6.1.1 Definition - The rated PEP of the transmitter in the peak envelope power delivered to the standard output termination at the manufacturer's specified level of intermodulation distortion products. 6.1.2 Duty Cycle - Transmitter rated PEP may be designated as either continuous, semi-continuous or intermittent according to the following test conditions: (a) Continuous - Transmitter operated continuously for 24 hours. This rating is limited to transmitters designed for continuous operation. (b) Semi-continuous - Transmitter operated continuously for eight hours. (c) Intermittent - Transmitter operated under a cycle of one minute on and four minutes off for a period of eight hours followed by three test cycles of five minutes on, fifteen minutes off. 6.1.3 Method of Measurement - The transmitter shall be operated in the A3J mode (carrier suppressed) at the rated duty cycle and no adjustments shall be made to the transmitter once the test has begun. The transmitter shall be modulated with the standard two-frequency test signal. A sample of the R.F. power output shall be fed to the standard frequency analyzer and the level of the two-frequency signals increased until the highest amplitude odd-order difference frequency intermodulation product is at least "X" dB below PEP. (See Paragraph 5,7) (It may be more than "X" dB below if the manufacturer wishes to decrease the distortion level at the expense of lower PEP output P rating.) The average power output ( avg) is then measured with an R.f. ammeter connected in series with the output termination. 4 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 P2 (Pay") is computed from the formula: avg = I R where: I - RMS current through R R - resistance of the standard output termination of the transmitter. Where an alternate power measurement is made, it should be so specified in the test report. P Rated PEP = 2 X ( avg) 6.1.4 Minimum Standard - The manufacturer’s rating of PEP for any category of equipment shall not be higher than that obtained under the relevant conditions of paragraph 6.1.3, and for: Category C equipment - shall not be less than 100 watts. Category V equipment - shall not be less than 30 watts. Category Y equipment - shall not exceed 30 watts. 6.2 Carrier Level 6.2.1 Definition - The carrier level is expressed as the ratio in dB, at the output of the transmitter, of the amplitude of the carrier to rated PEP. 6.2.2 Method of Measurement 6.2.2.1 Class A3J Emission - With the transmitter operating in the A3J mode, the two-frequency test signal shall be applied to the transmitter input at a level sufficient to produce rated PEP. One test frequency shall then be removed to establish a reference signal level 6 dB below rated PEP. The remaining test signal shall then be removed and the carrier voltage or power output measured. 6.2.2.2. Class A3H Emissions - The transmitter shall then be operated in A3H mode without modulation applied and the carrier voltage or power output measured. 6.2.2.3 Class A3A Emissions - The transmitter shall then be operated in A3A mode without modulation applied and the carrier voltage or power output measured. 5 Coast and Ship Station Single Sideband Radiotelephone Transmitters and Receivers Operating in the 1,605 - 28,000 kHz Band RSS-181 6.2.3 Minimum Standards - The power of the carrier for: Class A3J emissions, shall be attenuated at least 46 dB below rated PEP.