1、- EIA 424 75 3234600 0068443 7 .-* EIA STANDARD d cy d tx 4 in I Y Minimum Standards - Citizens Radio Service SSB Transceivers Operating in the 27 MIHz Band RS-424 February 1975 Engineering Department ELECTRONIC I NDUSTRIES ASSOCIATION EIA 424 75 3234b00 0068442 9 . NOTICE EIA engineering standards
2、are designed to serve the public interest through eliminating mis- understandings between manufacturers and purchasers, facilitating interchangeability and improve- ment of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need.
3、 Existence of sych standards shall not in any respect preclude any member or non-member of EIA from manufacturing or selling products not conforming to such standards. Recommended standards adopted by EIA are without any regard to whether or not their adop tion may in any way involve patents on arti
4、cles, materials, or processes. By such action, EIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the recommended standards. Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2001 Eye Street, N.W., Washington, D.
5、C, 20006 Q Electronic Industries Association 1975 All ribthta reserved Piice $4.25 Printed in U.S.A. I. MINIMUM STANDARDS . CITIZENS IRADIO SERVICE SSB TRANSCEIVERS OPERATING IN THE 27 MHz BAND (From EIA Standards Proposal No . 11 59-A formdated under the cognizance of EIA Committee TR-32 on Citizen
6、s Radio Equipment) TABLE OF CONTENTS 1 . SCOPE . 1 2 . STANDARD TEST CONDITIONS P 3 . POWER SUPPLY VOLTAGE RANGE . 3 Minimum Standards-Receiver 4 . SENSITIVITY . 3 5 . AUTOMATIC GAIN CONTROL . 4 6 . AUDIO SQUELCH THRESHOLD LEVEL . 5 7 . ADJACENT SIDEBAND REJECTION . 5 8 . SPURIOUS RESPONSE ATTENUATI
7、ON 6 9 . CROSS-MODULATION REJECTION 7 PO . RF INTERMODULATION REJECTION 7 11 . RECEIVER AUDIO OUTPUT POWER 8 12 . SPEECH CLARIFIER TEST 8 13 . RECEIVER AUDIO FREQUENCY RESPONSE 9 14 . IMPULSE NOISE LIMITER/BLANKER PERFORMANCE 9 15- RECEIVER SPURIOUS OUTPUT EMISSIONS . 10 . -1- . = EIA 424 75 W 3234b
8、00 0068444 2 W Minimum Standards-Transmitter 16. TRANSMITTER PEP POWER OUlPUT. . 11 17. TRANSMITTER CONDUCTED SPURIOUS EMISSIONS . 12 18. TRANSMITTER RADIATED SPURIOUS EMISSIONS. 13 19. TRANSMITTER AUDIO FREQUENCY RESPONSE .15 20. TRANSMITTER FREQUENCY STABILITY. 15 Minimum Standards-Environmentai 2
9、1. TEMPERATURE RANGE. 16 17 22. HIGH HUMIDITY 23. VIBRATION STABILITY. 18 24. SHOCKSTABILITY 18 . . -11- I. L- EIA 424 75 3234600 00bli45 4 = RS-424 Page 1 MINIMUM STANDARDS - CITIZENS RADIO SERVICE SSB TRANSCEIVERS OPERATING IN THE 27 MHz BAND 1. SCOPE This Standard details definitions and methods
10、of measurement of characteristics of SSB transmitters and receivers or SSB/AM transmitters and receivers, operating in the SSB mode, intended for opera- tion in the Class “D” Citizens Radio Service as defined in Part 95 of the FCC Rules and Regulations. The minimum standards herein apply to both upp
11、er and lower sideband modes of operation when they are provided and to all channel settings included in the equipment and over the range of carrier frequencies specified in 95.41 (d) of the FCC Rules and Regulations. This Standard is intended to promote the compatibility of these transmitters and re
12、ceivers with the systems in which they will operate. 2. STANDARD TEST CONDITIONS 2.1 Definition Standard test conditions are those conditions which shall apply to a transceiver while it isbeing tested for minimum requirements. These conditions shall apply unless otherwise specified. 2.2 Specific Sta
13、ndard Test Conditions 2.2.1 Power Supply Test Voltage is the primary voltage applied to the input of the power cable normally supplied with the equipment during all tests unless otherwise specified. Standard Test Voltage shall be as follows: Nominal Power Supply Voltage 6 VDC 12 VDC 24 VDC 32 VDC 64
14、 VDC 110 VDC 110 /i20 VDC 208 VDC 240 VDC Test Voltage 2.2.2 Standard Temperatures and Humidity shail be as followsl 25 C k 5O C and 90% maximum relative humidity. 6.6 Volts 13.8 Volts 26.4 Volts 36 Volts 72 Volts 110 Volts 121 Volts 211 Volts 242 Volts RS-424 EIA 424 75 3234600 00b844b b = Page 2 2
15、.2.3 Standard Transmitter Output Load shall consist of a 50 ohm resistive termination. Standard Loading Conditions for the RF output circuits shall be those specified by the manufacture in the literature normally furnished with the transceiver. 2.2.4 Automatic Level Control. The automatic level cont
16、rol (ALC) shall be operative for all tests of transmitter cerformance. 2.2.5 Standard Input Signal Source shall consist of a calibrated signal generator whose internal plus external resistance is 50 ohms, the voltage to be measured across terminals A and B, when A and B are terminated in a 50 ohm re
17、sistive load. Ge ne ru tor Re ce i ver R, -+ Rext = 50 Ohms 2.2.6 Standard Audio Beat Note. For receiver tests, unless otherwise specified, the CW standard input signal source shall be adjusted to produce an audio beat note of 1000 Hz ? 100 Hz. 2.2.7 Standard Audio Output Load for Receiver Tests sha
18、ll consist of a resistive load equal to the nominal output load specified by the manufacturer. 2.2.8 Standard Receiver Conditions. The receiver squelch control shall be unsquelched to its maximum extent unless otherwise specified, the noise blanker disabled and the RF gain control at full gain. 2.2.
19、9 Associated Equipment. The standard associated equipment to be used with the trans- ceiver during these tests is that with which it normally operates. 2.3 Method of Measurement 2.3.1 Mobile Equipment. .The cables normally supplied with the equipment should be full length and connected in the usual
20、manner as specified by the manufacturer. 3.3.2 Base Equiprtient. The primary voltage shall be measured at the power source to the equipment. 9 EIA 424 75 m 323qbOO 0068447 B m RS-424 Page 3 3. POWER SUPPLY VOLTAGE RANGE 3. Z Definition The Power Supply Voltage Range is the range of primary voltage o
21、ver which the transceiver wiil operate with a specific performance. 3.2 Minimum Standards 3.2.1 Over a voltage range equal to the standard test voltage f lo%, the following degradation limits shall not be exceeded: 3.2. I. 1 Transmitter Power Output 2 dB 3.2.1.2 Receiver Audio Output Power 2 dB 3.2.
22、1,3 Sensitivity 2 ClB 3.2.1.8 Audio Squelch Low Threshold Level 2 dB 3.2.1.5 Tight Squelch shall not lock out signals stronger than 500 volts. 3.2.2 The Transmitter Frequency Stability shall be maintained over a range of plus or minus 15% of standard test voltage. 3.2.3 Over a voltage range equal to
23、 the standard test voltage minus 20%, the equipment shall start and operate and the transmitter power output shall not drop more than 3 dB, nor shall the receiver sensitivity degrade more than 3 dB below the measured values at standard test conditions. 3.2.4 At a primary voltage of up to 15% above t
24、he standard test voltage, no short term failures shall occur although the life of the components may be reduced. MINIMUM STANDARDS - RECEIVER 4. SENSITIVITY 4.1 Definition The Sensitivity of the receiver section is the minimum value of a CW input sipal at a frequency that produces the standard audio
25、 beat note that will produce a 10 dB signal plus noise to noise (S + N)/N ratio. 1 I EIA 424 75 M 3234b00 00b844B T M RS-424 Page 4 4.2 Method of Measurement A standard input signal source shall be connected to the receiver antenna input terminals and the frequency adjusted to produce the standard a
26、udio beat note. A standard audio output load and voltmeter shall be connected to the audio output terminals. The volume control shall be adjusted for an audio output level approximately 6 dB below the rated audio output power. The standard input signal source attenuator shall be adjusted until the r
27、atio of audio output level with input signal to the audio output level without input signal is 10 dB. 4.3 Minimum Standards 4.3.1 For mobile or base equipment, the minimum Sensitivity shall be 0.5 microvolt. 4.3.2 For handheld, personal type equipment, the minimum Sensitivity shall be 1.0 microvolt.
28、 5. AUTOMATIC GAIN CONTROL 5.1 Defini tion The Automatic Gain Control performance of the transceiver is the measure of the ability of the unit to maintain a constant audio output level with varying input signal and the degree to which the re- ceiver prevents intermodulation distortion of the SSB sig
29、nal with strong input signal levels. 5.2 Method of Measurement 5.2.1 Static Compression Characteristics. A standard input signal source shall be connected to the receiver antenna input terminals and the frequency adjusted for the standard audio beat note. A standard audio output load and voltmeter s
30、hall be connected to the audio output terminals. The standard signal input signal source shall be adjusted to a level of 50,000 microvolts and the audio output level set to approximately 6 dB below the rated audio output power. The input level shall be varied from 50,000 microvolts to the rated 10 d
31、B (S + N)/N level and a plot of audio output level versus input level shall be prepared. 5.2.2 AGC Intermodulation Distortion. Using a spectrum analyzer, sample the intermediate frequency signal just after the last stage employing AGC. Through a 10 dB “T” pad apply two equal amplitude CW signals, th
32、e first of which produces a 1000 Hz beat note and the second of which produces a 1600 Hz beat note. Adjust the input signal level of each signal generator to 158,000 microvolts (10 dB greater than 50,000 microvolts). Observe and plot the attenuation of the third order intermodulation distortion prod
33、ucts (relative to either of the desired signals) versus the input signal level over the input level from 50,000 microvolts per signal to the rated input level per signal for a 10 dB (S + N)/N ratio. The AGC intermodulation distortion figure of merit is the attenuation of the least attenuated 3rd ord
34、er distortion product level expressed in dB, taken from the graph. EIA 424 75 m 3234600 0068449 IJ m RS-424 Page 5 5.3 Minimum Standards 5.3.1 Minimum Standard, Static Characteristics. The output versus input curve shall be free from sharp discontinuities. The ratio of maximum audio output level to
35、mini- mum audio output expressed in dB shall be the measure of AGC compression perform- ance. The maximum shall be 16 dB. 5.3.2 Minimum Standard, AGC Intermodulation Distortion. The AGC intermodulation distortion figure of merit shall be greater than or equal to 20 dB. 6. AUDIO SQUELCH THRESHOLD LEV
36、EL 6.1 Definition The Audio Squelch Threshold Level of a transceiver is the minimum value of a CW standard input signal source level which, when adjusted to produce the standard audio beat note, will open the receiver squelch. 6.2 Method of Measurement 6.2.1 Low Threshold. A CW standard input signal
37、 source shall be connected to the receiver antenna input terminals and adjusted to produce the standard audio beat note. A standard audio output load and voltmeter shall be connected to the audio output terminals of the receiver. With the input signal source adjusted 1 microvolt, the volume control
38、shall be adjusted for an audio output level approximately 6 dB below the rated audio output power. With no RF signal inpii t to the receiver, the squelch control shall be adjusted to quiet the thermal noise a minimiim of 20 dB over a ? 10% power supply VoltGe range. With the power supply voltage dju
39、sted for standard test conditions, the RF level of the input signal source shall be adjusted until the receiver produces continuous audio output not less than 10 dB below rated audio output. The minimum input signal level required to produce this condition is defined as the squelch low threshold lev
40、el. 6.2.2 Tight Threshold. After measuring the low threshold level, the receiver shall be measured for tight threshold level. The RF signal required to produce continuous audio output at the audio output reference level with the squelch control in its tightest position (usually one end of its mechan
41、ical range) is defined as the tight threshold level. 6.3 Minimum Standards The Audio Squelch Low Threshold Level shall be no greater than 0.5 microvolt and the tight threshold shall be no greater than 500 microvolts nor less than 30 microvolts. 7. ADJACENT SIDEBAND REJECTION ” 7.1 Definition Adjacen
42、t Sideband Rejection is the level to which the receiver intermediate frequency filter is able to suppress signals falling in the regionof theopposite sideband. EIA 424 75 = 3234600 00b8450 8 KS-424 Page 6 7.2 Method of Measurement After coupling a signal generator to the receiver antenna input termi
43、nals, adjust the frequency to produce the standard audio beat note. Attach a standard audio output load and voltmeter to the audio output terminals. Adjust the input signal level for an (S + N)/N ratio of 10 dB. Set the volume control for an audio output level at the rated audio output power minus 6
44、 dB. If the unit under test is capable of receiving both USB and LSB, change to the opposite mode. If the unit has only one sideband reception mode, use a frequency counter to shift the input signal 1000 Hz f 100 Hz to the opposite side of the suppressed carrier frequency. Increase the signal genera
45、tor level until the audio output reaches the reference level. The amount of increase, ex- pressed in dB, is the adjacent sideband rejection level. 7.3 Minimum Standard The Adjacent Sideband Rejection shall be greater than or equal to 40 dB. 8 SPURIOUS RESPONSE ATTENUATION 8.1 Definition A receivers
46、Spurious Response Attenuation is a measure of its ability to discriminate between a desired signal to which it is resonant and an undesired signal at any other frequency to which it is also responsive. 8.2 Method of Measurement A signal generator shall Be connected to the receiver under test and adj
47、usted for the standard audio beat note. The receiver under test shall be operated under standard test conditions. A standard audio output load and voltmeter shall be connected to the receivers audio output terminals. The output of the signal generator shall be adjusted for an (S + N)/N ratio of 10 d
48、B. and the volume control adjusted to produce approximately 6 dB less than the rated audio out- put power (reference audio level). The signal generator output shall be increased 60 dB and its frequency shall be variedover the continuous frequency range from the lowest radio frequency amplified in th
49、e receiver to 500 MHz and all responses shall be noted. The ratio of the signal generator voltage to produce the reference audio level at any spurious frequency to the signal generator voltage required to produce the same audio level when on channel frequency, expressed in dB, is the receivers attenuation to the spurious response. The spurious response which re- quires the least signal input to produce the reference audio level shall be used to express the receivers spurious response attenuation. 8.3 Minimum Standards The Spurious Response Attenuation shall be at least 35 dB except
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