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Фрагмент инструкции
Setting outside performance guarantee range: This message is displayed if a value is set outside the performance guarantee range. Level uncal: A value is set outside the output level accuracy guarantee range. > Even if this message is displayed, the output level is usually accurate provided that the message "RF Amplifier Abnormal" is not displayed. FM uncal: FM deviation is set outside the setting range. > The setting range of the FM deviation depends on the carrier frequency. If the FM deviation setting range at the current carrier frequency is exceeded, this message is displayed and the FM deviation becomes that of the upper limit of the setting range. AM uncal: The AM modulation is set outside the guarantee range. > This message is displayed if the AM modulation is set outside the performance guarantee range. Except for the above cases, various types of errors during remote control using GPIB are also displayed. For error messages relating to GPIB, see paragraph 6.5.5, "SCPI error messages." SECTION 4 OPERATING INSTRUCTIONS SECTION 4 OPERATING INSTRUCTIONS 4-52 . SECTION 5 MEASUREMENT 5.1 Measurement of Sensitivity The sensitivity of the receiver means the minimum signal input level required to output the rated signal of the receiver. The following incidental conditions are required for the signal level, noise level, and signal distortion obtained in the output side of the receiver: • AM receiver ............. Indicated by the minimum value of the typically modulated carrier voltage required to output the rated signal of the specified signal-noise rate (S/N). For example, when S/N = 20 dB, the minimum value of the carrier input voltage for 60 % modulation required to output the 50mW signal is indicated by 10 .V. • FM receiver.............. Indicated by the minimum value of the typically modulated carrier voltage required to obtain the rated output and specified value (–12 dB in 400 MHz) of the signal to noise and distortion (SINAD) obtained by adding the signal distortion to the signal-noise rate (S/N). In addition, this sensitivity is indicated by the minimum value of the carrier voltage required to suppress the receiver noise output by 20 dB at no-modulation. This is called a noise suppression (NQ) sensitivity. This section describes the latter 20 dB NQ sensitivity and explains how to measure the 12 dB SINAD sensitivity. SECTION 5 MEASUREMENT SECTION 5 MEASUREMENT 1 Measuring 20 dB NQ sensitivity The 20 dB NQ sensitivity is indicated the carrier input voltage (reading value of the output voltage of the signal generator) required to suppress the noise output by 20 dB when there is no 20 dB noise quieting, e.g., signal input. To obtain the noise output before suppressed, adjust the volume adjustment volume of the receiver so that the rated signal output is obtained. (1) Setup MG3641A/MG3642A DA FM RX DL LM (154.45MHz) Pseudo- antenna FM receiver Standard pseudo-load Level meter Fig. 5-1. Measuring 20 dB NQ Sensitivity (2) Measurement procedure STEP PROCEDURE 1. Set the MG3641A/MG3642A frequency to 154.45 MHz. 2. Set the MG3641A/MG3642A frequency deviation to 70 % (3.5 kHz for maximum frequency deviation 5 kHz) of the specified maximum frequency deviation. Then, set the internal modulation frequency to 1 kHz. 3. Set the MG3641A/MG3642A to a sufficiently high output (ordinarily 30 dB.or more) and apply it to the receiver. 4. Turn off the squelch of the receiver, synchronize the receiver with receiving frequency 154.45 MHz (so that the reading value of the level meter is the maximum), then adjust the volume adjust volume of the receiver so that the rated output of the receiver is obtained according to the indicator of the level meter. 5. Turn off the MG3641A/MG3642A output. 6. Use the level meter to measure the receiver noise output and set the meter indicator to 0 dB. 7. Turn off the MG3641A/MG3642A modulation and turn on the MG3641A/MG3642A output. 8. Adjust the MG3641A/MG3642A output level so that the indicator of the level meter is set to –20 dB. 9. The reading value of the MG3641A/MG3642A output level indicator is a 20 dB NQ sensitivity in step 8. SECTION 5 MEASUREMENT SECTION 5 MEASUREMENT 2 Measuring 12 dB SINAD sensitivity The SINAD sensitivity is indicated by the output level of the signal generator when the distortion rate reaches the determined value (–12 dB in the 400 MHz zone of Japan) by reducing the output level of the signal generator while measuring the distortion (correctly distortion + noise) of the receiving modulation output of the typically modulated signal. (1) Setup MG3641A/MG3642A DA FM RX DL LM (465.05MHz) Pseudo- antenna FM receiver Standard pseudo-load Distortion rate and noise meter Fig. 5-2. Measuring 12 dB SINAD Sensitivity (2) Measurement procedure STEP PROCEDURE 1. Set the MG3641A/MG3642A frequency to 465.05 MHz. 2. Set the MG3641A/MG3642A frequency deviation to 70 % (3.5 kHz for maximum frequency deviation 5 kHz) of the specified maximum frequency deviation. Then, set the i...
Эта инструкция также подходит к моделям:Электрогенераторы - MG3641A (1.18 mb)