Parts List

Transmitter Main Board Instruction Manual 1-1
1 GENERAL
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1.1 Introduction
The MT-3 Transmitter Main Board integrates the MT-3 Front Panel Board, MT-3 Audio
Processor, Synthesizer or Crystal Controlled Oscillator module, and Amplifier module together to
comprise a MT-3 series transmitter (see section 5.1: MT-3 Transmitter Block Diagram). The Front
Panel Board and the Audio Processor are soldered directly to the Transmitter Main Board while the
Amplifier and the Synthesizer or Crystal Controlled Oscillator module are frequency band sensitive,
plug-in modules. Circuitry and jumpers on the Transmitter Main Board control the operation of the
modules as well as the overall operation of the MT-3 transmitter. Power and signal connections are
made through the 48 pin type 'F' connector on the rear of the Transmitter Main Board where they
are then routed to the other MT-3 modules. The front and rear panels are attached to the
Transmitter Main Board and together with the extruded aluminum shell, form the transmitter
enclosure.
1.2 Performance Specifications
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1.2.1 General
Type: MT-3 Series Transmitter
Compatibility: MT-3 Series Amplifier, OC-3 Crystal Controlled Oscillator
module, OS-3 and OS-3H Frequency Synthesizer modules.
Modulation: 11K0F3E or 16K0F3E (Frequency Modulation).
Operating Temperature Range: -30˚C to +60˚C, optional -40˚C to +60˚C temperature test.
Operating Humidity: 95% RH (non-condensing) at +25°C.
Operating Voltage: +9.5 Vdc Regulated. +13.8 Vdc Nominal (11 - 16 Vdc).
Front Panel Controls: NORM (r epeat mode), OFF, and KEY TX (Tx on).
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.).