Audio Interface; Line Out - Tait TM8000 Service Manual

isolated E&M interface with a flexible range of configurations
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unbalanced audio input and output
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all audio I/O is adjustable by high precision 12-turn potentiometers which are
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accessible by opening the radio lid
open collector gate output
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3.3V TX key input
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analogue RSSI and auxiliary microphone lines from radio available as I/O
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options
optional RX line to TX line adjustable level talk-though for headset side tones
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and voice recorder systems
radio internal serial port available as I/O options
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programmable tail/hang time
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programmable 'anti-kerchunker' timer
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programmable supply voltage alarm with beeps superimposed on radio TX
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audio
PC based real time monitoring of input and output conditions
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field upgradable software for future upgrades.
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2.1

Audio Interface

The audio interface consists of two sections.

Line out

The line out audio interface features:
radio RX audio to a balanced 600 ohm transformer isolated output
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radio RX audio to an unbalanced 100 ohm un-isolated output.
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The line out audio source is software selectable between the fixed level
AUD_TAP_OUT line or the volume controlled RX_AUX line of the TM8000/
TM9000 radio. The audio mute characteristics and flat/de-emphasised
configuration of AUD_TAP_OUT is defined in the programming of the radio
audio options. RX_AUD is de-emphasised and is controlled in level according to
the control head volume control.
Caution
The audio output level is adjusted by potentiometer VR1. Various TA2922
configurations are available from Tait Electronics with the audio output set to a
pre-defined level.
14
In some TM8000/TM9000 configurations the RX_AUD
line becomes fixed in level and is not controlled with the
radio's volume control, such as when remote head or
multi head configurations are used. Consult your Tait
dealer for more information.
TA2922 Universal Line Interface Service Manual
© Tait Electronics Limited March 2010