Spectrum Management and Telecommunications

RSS-117 - Land and Coast Station Transmitters Using A1, A2, A3, A2H, or A3H Emissions Operating in the 200-535 kHz Band

Issue 2, March 1974

Spectrum Management and Telecommunications
Radio Standards Specification

1.0 Intent
2.0 General
3.0 Related Documents
4.0 Equipment Requirenments
5.0 Standard Test Conditions and Definitions
6.0 Tests Under Standar Test Conditions
7.0 Tests Under Environmental Conditions

RSS-117 - Land and Coast Station Transmitters Using A1, A2, A3, A2H, or A3H Emissions Operating in the 200-535 kHz Band(PDF, 308 KB, 13 pages)

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1.0 Intent

1.1 This Specification sets forth the minimum performance standards required for the type-approval of radio transmitters described by the above Specification title.
1.2 Submission for the type-approval of radio transmitters shall be made under one of the following categories:
1. Transmitters designed to operate under temperature extremes – 40^oC to +55^oC
2. Transmitters designed to operate under temperature extremes – 10^oC to +55^oC
3. Transmitters designed to operate under temperature extremes – 0^oC to +55^oC
These letters will be suffixed to the type-approval number according to the category under which the equipment is approved.
1.3 Transmitters type-approved in accordance with the requirements of this Specification are considered technically suitable for licensing pursuant to the Radio Regulations made under the Radio Act.

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2.0 General

2.1 Those seeking approval of equipment under this Specification shall satisfy the Department at their own expense that the equipment actually meets the requirements of this Specification.
2.2 Notwithstanding the fact that an equipment may be type-approved, the Department reserves the right to require that adjustments be made to that equipment if it causes interference within the meaning of the Radio Act.
2.3 This Specification sets forth minimum standards only for certain parameters. Some users may wish to specify additional or more stringent requirements to achieve their particular needs. However, this may not be done at the expense of simultaneously degrading performance below the minimum standards contained herein.
2.4 The Department reserves its right to revise this Specification.

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3.0 Related Documents

3.1 Radio Standards Procedure 100 – Procedure for obtaining Type-Approval of Equipment for Licensing.

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4.0 Equipment Requirements

4.1Power Output Limitation
- 4.1.1 In the case of SSB transmitters the maximum output of the transmitter shall be automatically limited to a level not in excess of 1 dB above the manufacturer's rated peak envelope power (PEP).
- 4.1.2 Limiting action shall be accomplished in such a manner that when operating in the A3H mode the carrier is not reduced below -6 dB relative to PEP.
4.2 Beacon Transmitters – Transmitters used as radio beacons shall have an output modulated at 1020 or 400 Hertz as specified by the manufacturer. The tolerance on these tones shall be ± 5%.
4.3 Equipment Identification– The following information shall be permanently displayed on each transmitter:
1. Type-approval number.
2. Serial number of equipment.
3. Applicant's name.
4. Model identification.

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5.0 Standard Test Conditions and Definitions

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 shall apply unless otherwise specified.
5.2 Test Voltage – The test voltage shall be the voltage applied to the power input terminals of 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^oC ± 5^oC.
5.4 Test Frequencies – All tests shall be made on at least two carrier 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.
5.5 Output Termination – The output termination shall be a nominal 50 ohm resistive load, or as stated by the manufacturer.
5.6 Standard Test Modulation
- 5.6.1 A2/A3 Transmitters – Test modulation shall be 50% at 1000 Hz sinusoidal.
- 5.6.2 A2H/A3H Transmitters – Test modulation shall consist of applying a two-frequency test signal in accordance with paragraph 5.6.2.1 or 5.6.2.2 as applicable.
  - 5.6.2.1 Conventional A2H/A3H Transmitters – The two-frequency test signal shall consist of the carrier and a sinusoidal audio frequency signal of 2000 Hz. The audio signal shall be applied to the audio input terminals of the transmitter. The carrier and audio signals shall be adjusted to produce two equal amplitude r.f. signals at the output of the transmitter.
  - 5.6.2.2 Special A2H Beacon Transmitters – These are transmitters in which the A2H mode is generated by two r.f. oscillators. One oscillator shall operate at the carrier frequency ("carrier oscillator") and the other ("sideband oscillator") shall operate at 1020 or 400 Hertz (± 5%) above the carrier. The operating level of these two oscillators shall be adjusted to produce two equal amplitude radio frequency signals at the output of the transmitter. For test purposes, the "sideband oscillator" shall not be keyed.
5.7 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.
5.8 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 transmitter conforms to Fig. 1 or the final amplifier dissipation rating is reached, whichever occurs at the lower power output.
5.9 Spectrum Analyzer – The resolution and accuracy of the spectrum analyzer or equivalent instrument used for testing shall be stated in the test report.
5.10 Rated Duty Cycle – Transmitters shall be operated (carrier "on") under one or more of the following duty cycles as specified by the manufacturer:
1. Continuous – The transmitter shall be operated continuously for twenty-four hours. This rating is limited to transmitters capable of continuous operation.
2. Semi-continuous – The transmitter shall be operated continuously for eight hours.
3. Intermittent – The transmitter shall be operated under a cycle of one minute carrier "on" and four minutes carrier "off" for a period of eight hours followed by three test cycles of five minutes "on", fifteen minutes "off".
5.11 Necessary Bandwidth – For the purposes of this specification, values of Necessary Bandwidth corresponding to various types of emission shall be as shown in the following table:

Necessary Bandwidth
Type of Emmision	Necessary Bandwidth
A2	2 x Highest tone used
A3	6000 Hertz
A2H	Highest tone used
A3H	3000 Hertz

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6.0 Tests Under Standard Test Conditions

6.1 Power Output Rating
- 6.1.1 Definition – Power Output Rating is the minimum r.f. power dissipated in the output termination under the rated duty cycle specified by the manufacturer and as under the conditions specified in 6.1.2.
- 6.1.2 Method of Measurement
  - 6.1.2.1 Al/A2/A3 Transmitters – The transmitter shall be operated unmodulated at the rated duty cycle (paragraph 5.10) and loaded into the output termination. The average r.f. power output shall be measured and recorded for the duration of the test. All details of the measurement shall be clearly described in the test report.
  - 6.1.2.2 A2H/A3H Transmitters – The transmitter shall be operated in the A3H mode at the rated duty cycle (paragraph 5.10) with the test modulation (paragraph 5.6.2) applied. A sample of the r.f. power output shall be fed to a spectrum analyzer and the output level of the two-frequency signal shall be adjusted, so that the output spectrum of the transmitter conforms with the limits of Fig. 1. No adjustments shall be made to the transmitter after the initial set-up. The average r.f. power output (Pavg) shall be measured and recorded for the duration of the test. Peak envelope power, PEP = 2 x Pavg. All details of the measurement shall be clearly described in the test report.
- 6.1.3 Minimum Standards – The manufacturer's rating of r.f. power output shall not exceed the minimum power recorded under paragraph 6.1.2.1 or 6.1.2.2. For A2H/A3H r.f. power rating shall be in terms of PEP.
6.2 Spurious Emissions
- 6.2.1 Definition – Emissions on a frequency or frequencies which are outside the necessary band the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, paragraphsitic emissions and unwanted intermodulation products which are remote from this band.
- 6.2.2 Methods of Measurement
  - 6.2.2.1 Test A – Emission on frequencies close to the necessary band
    The transmitter shall be operated into the output termination under the modulation conditions specified in paragraph 5.6 except that:
    1. in the case of A2/A3 transmitters the modulating frequency shall be 2000 Hz and the modulation shall be adjusted to 95%; and
    2. in the case of A2H/A3H transmitters the carrier level shall be adjusted to that obtained at rated PEP in paragraph 6.1.2.2 and the side band signal level shall be adjusted to the carrier level. A sample of the r.f. output shall be fed to a spectrum analyzer or equivalent instrument. The level and frequencies of each significant output component with reference to the level of the unmodulated carrier shall be measured and plotted (See Fig. 1) over a band of frequencies equal to ± 250% of the necessary bandwidth.
  - 6.2.2.2 Test B – Emission on frequencies remote from the necessary band
    The transmitter shall be operated as in paragraph 6.2.2.1 above, except that the modulation or the side band signal shall be removed. The output spectrum shall be carefully searched over the frequency band having a lower limit of 10 kHz , and an upper limit of 5 MHz excluding the band of frequencies covered in Test A above. All significant spurious outputs shall be identified and their levels with reference to the output level of the carrier shall be measured and recorded.
- 6.2.3 Minimum Standards
  - 6.2.3.1 Under Test A above, no emission when plotted shall lie in the cross-hatched area of Fig. 1.
  - 6.2.3.2 Under Test B above, all single frequency outputs shall be at least 40 dB below the carrier level and in no case shall exceed 25 milliwatts.
6.3 Audio Frequency Response (Applicable only to transmitters designed for A3 or A3H operations)
- 6.3.1 Definition – The term audio frequency response is defined in terms of the variation in the demodulated output power produced by a constant amplitude audio input signal which is varied over a specified frequency range.
- 6.3.2 Method of Measurement – The transmitter shall be operated under standard test conditions with modulation applied as specified in paragraph 5.6 except in the case of A3H transmitters
  1. the modulating frequency shall be 1000 Hz
  2. the carrier level shall be adjusted to that obtained at rated PEP in paragraph 6.1.2.2
  3. the side band signal level shall be adjusted to 50% of the carrier level.
    The modulating signal level shall be kept constant and its frequency shall be varied from 100 to 4000 Hz. A sample of the transmitter output shall be demodulated by suitable means. Measurements of the demodulated output shall be recorded. These shall be corrected by taking into account the response characteristics of the measurement device(s) which shall be stated in the test report. Measurements shall be made at a sufficient number of modulating frequencies to plot a curve of relative output vs modulating frequency in accordance with Fig. 2. The measured output at 1000 Hertz shall be zero reference level.
- 6.3.3 Minimum Standards – The audio frequency response curve as plotted under paragraph 6.3.2 shall lie between the cross-hatched areas of Fig. 2.
6.4 Hum and Noise Output Level
- 6.4.1 Definition – Hum and noise output level is defined in terms of the ratio of transmitter demodulated output under specified conditions of modulation to that under conditions of no modulation.
- 6.4.2 Methods of Measurement
  - 6.4.2.1 A2/A3 Transmitters – The transmitter shall be operated under standard test conditions except that it shall be modulated 95%. A sample of the transmitter output shall be demodulated and measured by suitable means. The modulation shall then be removed from the transmitter and the change in demodulated output measured and recorded.
  - 6.4.2.2 A2H/A3H Transmitters – The transmitter shall be operated under standard test conditions at rated PEP output. A sample of the transmitter output shall be demodulated and measured by suitable means. The sideband signal shall then be removed from the transmitter and the change in demodulated output measured and recorded.
- 6.4.3 Minimum Standard – The hum and noise output level (unmodulated output level) shall be at least 40 dB below the modulated output level.

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7.0 Tests Under Environmental Conditions

7.1 Tolerances – The maximum allowable tolerances on voltage, temperature and humidity measurements shall be as follows:
1. Temperature: ± 3^oC
2. Voltage: ± 2%
3. Humidity: ± 5%
For the purpose of these tests, equipment temperatures shall be considered stabilized when the temperature of the largest internal mass remains within ± 3EC of the specified value when the equipment is inoperative or when the crest temperature of the largest internal mass does not vary by more than ± 5EC with equipment operating.
7.2 Operational Stability Performance
- 7.2.1 Definition – The term "Operational stability performance" refers to the ability of the transmitter to operate with no more than a specified amount of degradation in performance at any point throughout the extremes of temperature and supply voltage and following exposure to extremes of temperature and humidity.
- 7.2.2 Method of Measurement – Frequency measurements of the unmodulated carrier shall be made at one-minute intervals under the conditions given below. The frequency measuring instrument shall have an accuracy of at least 0.001%.
  1. Standard Test Frequency – The equipment shall be placed in a test chamber inoperative until the equipment temperature is stabilized at 25^oC. At the end of this period, and allowing up to one hour for warm up, the transmitter shall be placed in operation under standard test conditions, under the appropriate duty cycle with modulation (1020 Hz tone or "side band oscillator") switched off. The frequency shall then be measured and recorded at one-minute intervals for a period of fifteen minutes and the average frequency computed. This shall be the Standard Test Frequency.
  2. Temperature and Voltage Extremes – The temperature and voltage shall then be varied throughout the entire environmental range as follows: Temperature, as specified for appropriate category (paragraph 1.2) voltage, ± 10% of standard test voltage. Performance measurements shall be made at the temperature extremes using standard supply voltage ± 10% and at each significant temperature throughout this range. Allow equipment to stabilize at each temperature where measurements are to be made.
    1. Frequency measurements shall be made at one-minute intervals for a five-minute period and recorded.
    2. The r.f. power output shall be measured and recorded at regular intervals.
  3. Temperature and Humidity Extremes – The equipment shall be placed inoperative in a test chamber at a relative humidity in excess of 95% and ambient temperature of 40^o for a period of eight hours. After this time, the equipment shall be taken from the chamber and any condensed moisture may be drained off. Standard test minutes of removal from the chamber. Fifteen minutes may be allowed for warm up time following the application of primary power to the equipment immediately following the warm up period,
    1. frequency measurements shall be made at one-minute intervals for a five-minute period, and
    2. the r.f. power output shall be measured. All measurements shall be recorded.
7.3 Minimum Standards
1. The maximum departure, under any environmental condition, of the measured frequency from the Standard Test Frequency shall not exceed 0.01% of the Standard Test Frequency.
2. The transmitter r.f. power output under any environmental condition shall not degrade more than 3 dB below the power output rating obtained under standard test conditions (See paragraph 6.1).