Definition and Purpose. In one (1) hand-held unit, the AM-48 provides the field engineer with two (2) instruments: 1. a transmission test set, and 2. a telephone "butt-set". The transmission test set tests the integrity and quality of 2-wire or 4-wire voice and data transmission lines by sending selected analog signals and measuring standard parameters of the received signals. The telephone "butt set" enables the field engineer to dial up and speak back-and-forth with a field engineer at the far end of the system. The compact and light-weight AM-48 eliminates the need to carry multiple, bulky test sets. Functional Overview AM-48 can send: • any frequency from 200 Hz to 20 kHz @ -50 to +10 dBm • continuous 3-tone slope (404, 1004, 2804 Hz) • continuous, user-defined, sweep tones • fixed 1004 Hz • P/AR waveform • momentary 2713 Hz for WECO 829 loopback AM-48 can measure: • level, -65 to +10.9 dBm (absolute or relative) • frequency, 0 to 19,999 Hz • idle channel noise • noise with tone • three-level impulse noise • phase jitter • gain jitter • transients (dropouts, phase and gain hits, impulse noise) • signal-to-noise (S/N) ratio • peak-to-average ratio (P/AR) Noise filters provided (each with optional 1010 Hz notch):: • C-Message (Psophometric for AM-48E) • 3 kHz • 15 kHz • Program (Sound-weighted for AM-48E) Other features: • High impedance bridge, 600 or 900 Ohm termination • Display prompts help in set-up and testing sequences • On-board memory can store & recall up to 10 user-defined test set-ups • Dials: pulse, DTMF, and MF • Talk/Listen capability • Printer interface for hard copy of set-up and test results • Battery life: Alkaline, 6 to 7 hours; NiCad, 3 to 4 hours • NiCad batteries can be recharged without removing them from the unit Testing Configurations: (For details, see ¶6.6) There are three (3) basic AM-48 configurations used to test 2-wire/4-wire telephone/data communication lines: 1. End-to-end -- requiring two (2) AM-48 units 2. Loopback 3. Testing with responders