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Published byCharlotte Craig Modified over 9 years ago
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FREQUENCY CONTROL MODES OF ET 92 To learn more click on note! END to END Loss Measurement Group Delay Distortion Measurement Frequency Tracking with Sweep Fr receiver = Carrier ± Fr transmitter Conventional Control Modes Special Receiver Control Modes Measurements with MTTS Frequency Modification with Cursor Keys Frequency Setting with Number Keys Fr receiver = Carrier ± Tone ELEKTR NIKA
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Frequency Setting with Number Keys To set a new frequency use the NUMBER keys as usual. E.g. 3825 Hz Notice: don’t touch the cursor keys Option ELEKTR NIKA
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Frequency Modification with Cursor Keys The frequency STEP can be modified with the HORIZONTAL cursor keys The FREQUENCY can be modified with the VERTICAL cursor keys FREQU: 100.000 kHz FREQU: 100.100 kHz FREQU: 100.200 kHz Notice: don’t touch the number keys Option ELEKTR NIKA
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Frequency Tracking with Sweep Selectable ranges For OptionsFor Next/Loss Option ELEKTR NIKA
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Receiver Frequency Setting in Carrier ± Tone Format Set carrierSet tone Select mode Final display format Test instructions of FDM systems often specify the test frequency in format: Carrier ± Channel ( Tone) Frequency. ET 92 provides the separate setting of carrier and tone frequencies and so: No frequency calculation is required! ELEKTR NIKA
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Special Transmitter Tracking Mode Often used test procedure of FDM equipment is: ■ feeding audio frequency test signal to the input of the tested channel ■ measuring the level of modulation product at a high frequency test point In that case: Receiver Frequency (Rx)= Carrier ± Transmitter Frequency (Tx) ET 92 provides a special transmitter tracking mode. In that special mode: ■ The frequency range of transmitter: 200Hz to 4 kHz ■ The level meter is controlled by the generator according to the above mentioned rule. ADVANTAGES: No frequency calculation is required ! Only one frequency setting is required ! ELEKTR NIKA
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END to END Loss Measurements with MTTS MTTS METHOD: ■ The transmitter generates 35 test tones ■ The receiver measures the 35 test tones simultaneously ADVANTAGES: ■ No synchronisation is necessary between the two instruments ■ The measuring time is shorter than that of other methods ELEKTR NIKA
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Group Delay Distortion Measurement with MTTS MTTS METHOD: The transmitter generates 36 test tones ■ Frequency range: 100 to 3600 Hz ■ Frequency step: 100 Hz ■ Level: -20 dBm / frequency The receiver measures the 36 test tones simultaneously ADVANTAGES: ■ No synchronisation is necessary between the two instruments ■ Group delay and signal level measurement at the same time ■ The measuring time is shorter than that of other methods ET 92 applies the multi tone test method described in Recommendation ITU-T O.81 Appendix I ELEKTR NIKA
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