m3trc_eng (08.01.02)
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Kompetent für Elektroniksysteme
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Kompetent für Elektroniksysteme
Major 3 TRC
General Operating Instructions
The Major 3 is controlled by a micro processor. It is used to control radio systems. To program
the Major 3 you use easily the keyboard.
There are two main versions of Major 3. One for use with 12 V DC main power and one with
integrated 230 V AC power supply.
On the rear side is 25-pin connector. This is for connecting squelch input, ptt output, audio in/output,
5 plus 1 digital outputs. You can also connect the DC power to this.
The Major 3 with option FFSK/RS232 has an RS232 Interface. You can use it to program the Major
3 or connect a terminal for special purposes.
Only the Major 3 for 230 V AC has an power switch on the rear side. After switching on the display
shows for one sec. <Futro>. Then the cursor flashes for input.
Before first use of Major 3, you have to adjust audio levels to the radio.
Busy Indicator and carrier input
The busy indicator and as well the carrier input is programmed with EEPROM register 053 on 1.
position. Any voltage from 0 to 2 volt is detected as low and a voltage from 3 to 12 volt as high. If you
have an 2-wire connection you can use the carrier input to transmit a programmed tone sequence. In
case of a two-wire system the busy indicator is controlled by voice activity.
Register 053
1. position busy indicator on when
0 = carrier input < 2V
1 = carrier input > 3V
2 = audio squelch, 2-wire connection
3 = audio squelch, 2-wire connection, transmitting tone sequence when
carrier input is true
Loudspeaker indicator
Is switched on if the loudspeaker is open. The indicator flashes if an incoming call is detected. In
this case the loudspeaker is also switched active.
Loudspeaker
To change the volume push the button loudspeaker key. The display shows <VOL> and now you
can enter a new value from 0 to 9.
You can switch on and off the loudspeaker by pushing the loudspeaker key. The loudspeaker is also
active after pushing the PTT, after transmitting a call or if a incoming call is detected.
The loudspeaker is switch of manually by the loudspeaker key or automatically with a programmable
timer.
