RELM Communications Inc SRU50ABC User Manual
S Series Repeater USER MANUAL
©RELM Communications Inc. Revision 1.0
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12
12
8
TX PTT IN.
The standard PTT input is normally active low and may be driven from standard
logic outputs or open collector. JMP9 should be in and JMP8 in position 1-2. To
change polarity or voltage input also see OPTO PTT IN. Removing JMP9 will
input the PTT via the opto coupler.
The standard PTT input is normally active low and may be driven from standard
logic outputs or open collector. JMP9 should be in and JMP8 in position 1-2. To
change polarity or voltage input also see OPTO PTT IN. Removing JMP9 will
input the PTT via the opto coupler.
4
5
9
RX DISCRIMINATOR.
The receiver discriminator audio output is buffered, unfiltered and DC coupled to
this point. Output impedance is low.
The receiver discriminator audio output is buffered, unfiltered and DC coupled to
this point. Output impedance is low.
11
13
10
TX OPTO PTT IN.
This input is only used if a floating or opto input PTT is required. JMP9 MUST be
removed. Positive or negative keying voltage can be applied to the input due to full
wave rectifier and opto circuit. For a fully floating differential input voltage (+/-5
to +/-48 VDC) set jumper JMP8 in position 1-2. Putting JMP8 in position 2-3 will
connect this point to earth.
This input is only used if a floating or opto input PTT is required. JMP9 MUST be
removed. Positive or negative keying voltage can be applied to the input due to full
wave rectifier and opto circuit. For a fully floating differential input voltage (+/-5
to +/-48 VDC) set jumper JMP8 in position 1-2. Putting JMP8 in position 2-3 will
connect this point to earth.
3
6
11
TX FORWARD POWER.
The voltage from the forward power directional coupler in the Power Amplifier
goes directly to this pin. In a correctly terminated load the voltage should be about
3-4 Volts for 50 Watts. The output impedance is about 5K
The voltage from the forward power directional coupler in the Power Amplifier
goes directly to this pin. In a correctly terminated load the voltage should be about
3-4 Volts for 50 Watts. The output impedance is about 5K
Ω. The internal forward
power control circuit also monitors this point.
10
14
12
ANALOG EARTH.
General analog earth common for VF input and output.
General analog earth common for VF input and output.
2
7
13
TEMPERATURE OUTPUT.
The temperature output voltage is proportional to the temperature on the power
amplifier heatsink.
The temperature output voltage is proportional to the temperature on the power
amplifier heatsink.
9
15
14
TRANSMIT AUDIO INPUT 600
Ω
Ω
Ω
Ω.
Transmitter audio input to op-amps etc. Nominal line input level is -10dBm. Can
handle levels to greater than +10dBm. Common return to analog Earth.
handle levels to greater than +10dBm. Common return to analog Earth.
1
8
15
RX RSSI OUTPUT.
The receiver's received signal strength indicator voltage is proportional to the log
of the signal level at the antenna input. Voltage range is 0 to 5 volts. Output
impedance is low. Dynamic range > 60dB.
The receiver's received signal strength indicator voltage is proportional to the log
of the signal level at the antenna input. Voltage range is 0 to 5 volts. Output
impedance is low. Dynamic range > 60dB.
NC
NC
16
WIDE BAND TX MODULATION INPUT.
Wide band audio or data may be connected to this point. WARNING: In order to
conform to transmitter bandwidth emissions limits, the signal MUST be pre-
filtered, failure to do this WILL result in non-compliance of the Tx emission
spectrum. This input is not normally used except in special cases.
Wide band audio or data may be connected to this point. WARNING: In order to
conform to transmitter bandwidth emissions limits, the signal MUST be pre-
filtered, failure to do this WILL result in non-compliance of the Tx emission
spectrum. This input is not normally used except in special cases.