2-12
Transmitter Main Board Instruction Manual
with the voice signals to be output from the standard Modulation Output port while Subtone 2 is
not used. Both subtone inputs have an input level control.
2.3.4.9
Audio Processor Direct Modulation Input
The Direct Modulation Input is an extremely versatile input. This port is designed to be used for
data signals. Depending on the application, the signal can be amplified, AC or DC coupled and
output to the Modulation Output or the Low Frequency / Direct Modulation Output port. Please
consult the factory for specific jumper settings for your application.
2.4
MT-3 Audio Processor (Version 1.8)
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2.4.1 General
The MT-3 Audio Processor is a versatile circuitboard that can provide several types of audio
processing for voice or data transmission. Two analog switches on the audio processor, controlled
by a common signal, make it possible to transmit voice or data. A continuous +9.5 Vdc supply
and a sw8.0 Vdc supply are required to power the module. The MT-3 Audio Processor is
backwards compatible to Daniels Electronics MT-2 series transmitters. Refer to section 5.5.1
"MT-3 Audio Processor Component Layout" and to section 5.5.2 "MT-3 Audio Processor
Schematic Diagram" for component location and designation references.
2.4.2 Power Requirements
The audio processor can be configured for continuous audio standby or for switched audio standby
by the Transmitter Main Board. If fast audio risetime is desired, the transmitter should be operated
in standby mode 2 or 3 as specified in section 2.1.2.7 with JU36 on the audio processor in the 'y'
position. Power for the microphone input and the balanced input can be disabled by jumpers JU36
and JU40 respectively if the input is not required. This results in a current savings of
approximately 3.5 mA per input. The current requirements for the MT-3 Audio Processor are
shown in Table 3-1. The current for the associated TOT is approximately 4 mA when the
transmitter is keyed. The keyed values in the table below do not include the current for the TOT.
Summary of Contents for VT-3/140-SWA2
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