Jotron AS| TR7750C: Operators Manual Functional description
P/N: 84748 (G)
3.1.5 LED Indicators
LOW (yellow): The transmitter transmits in low power, either caused by an internal failure
(SWR, Temperature, or low input voltage) or set by the user. The low power
level is adjustable.
AL (red): Indicates that an alarm is present in the transmitter unit. Details of the alarm
will be shown on the display.
REM (green): This LED has multiple functions. The REMOTE indicator will be lit with a
constant green colour when the transmitter is “ready” for remote operation.
Ready means that the keying options has been set to include keying from an
external source, and that the voice input has been set to an external source
(600 ohm line input).
In addition the REMOTE indicator will flash yellow each time the unit is
communicating on either of the remote interfaces (RS232, RS485, Ethernet).
STBY (yellow): The transmitter is kept in standby, either by user input, an external signal to
the remote interface or because an alarm condition has been detected, and
the transmitter is set up as a MAIN transmitter. In standby the transmitter
will not be able to send, even if a valid key signal is input to the unit.
OUT (yellow): Indicate that the transmitter is keyed and power is being generated. The LED
is activated based on RF detected on the output of the power amplifier, thus
the LED gives an indication that power is generated.
SWR (red): Indicate that the SWR on the antenna is above the threshold value (app. 3:1).
The transmitter will reduce the output power to the predefined low power
level in order to protect the output stage.
3.1.6 Mic/Headset connector
Table 3.1-1, Mic/Headset connector, transmitter, pin out
The Mic/Headset connector is used for multiple purposes:
Microphone/Headset connector:
Connect the microphone to the Mic input/Mic GND, the +12VDC can be used to power the
microphone or a microphone amplifier. The +12VDC is current limited at 100mA.
The Headset output (referenced to GND) contains the local sidetone generated from the
demodulated signal on the output of the transmitter when the transmitter is keyed, or the
Dynamic. Sensitivity 2.5mV nominal.
Reference input for mic signal
Headset output, contains sidetone and/or received
audio when used with a receiver (RA7203)
PTT input. Connect to GND (p.8) to key
+12 VDC to mic. Amplifier (10mA)