User's Guide

1-2 Transmitter Main Board Instruction Manual IM20-MT3TXMN
PTT Activation: • Active to ground with or without time-out-timer.
• Microphone activated with or without time-out-timer.
• Front Panel switch: KEY TX - without time-out-timer.
• NORM - with or without time-out-timer.
• Isolated (optional relay) with or without time-out-timer.
PTT Time-Out-Timer: Selectable from 1 sec. to 8 hrs. (Factory Default: 5 min.).
1.2.2 Audio Specifications
Audio Input: Balanced 600 ohm or unbalanced (optional).
Input level sensitivity, -25 dBm to 0 dBm.
Audio Response: Pre-emphasis (6 dB per octave); +1.0 to -1.0 dB
from 500 Hz to 2.5 kHz;
Flat Audio Response: +1 to -1 dB from 300 Hz to 2.5 kHz.
Audio Deviation: Preset to ±1.5 kHz (Narrow Band) or ±3.0 kHz (Wide Band)
with a 1 kHz tone (capable ±2.5 kHz or ±5.0 kHz).
Subtone Audio Input 1: 0.5 Vpp at 200 Hz for ±500 Hz deviation
(internally adjustable).
Subtone Audio Input 1 Frequency range: 60 Hz to 300 Hz.
Subtone Audio Input 2: 0.5 Vpp at 100 Hz for ±500 Hz deviation
(internally adjustable).
Subtone Audio Input 2 Frequency range: DC to 150 Hz.
Direct Modulation Input: 0.5 Vrms at 1 kHz or ±3 kHz deviation.
Direct Modulation Frequency range: DC to 5 kHz.