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17.3 RF SENSOR ADJUSTMENT
The amplifier is switched off for this adjustment.
Check if adjustment is required as per following procedure, before opening the sensor.
Unsolder and remove the metal cover.
Connect a transceiver to the input and a dummy load to the output of the amplifier.
Connect a voltmeter to pin SW1 or SW2 on the control board (with yellow/black wires).
Apply 30-50W RF on 20m (14.2MHz) and read the voltage.
Move the voltmeter on pin SW3 or SW4 (red/black wires) and read the voltage.
Typical readings:
-
Yellow / black wires: 1 – 1.5 V
-
Yellow / red wires: 100mV or less
Adjust the trimmer on the output side (left hand side) in the RF sensor for minimum reading on the yellow / red wires.
(Use an RF screwdriver).
Reverse the 2 RF cables: apply power to the output of the amplifier and put the dummy load on the input.
Apply power again.
The typical readings are the same, but reversed:
-
Yellow / black wires: 100mV or less
-
Yellow / red wires: 1 – 1.5 V
Adjust the trimmer on the input side (right hand side) in the RF sensor for minimum reading on the yellow / black wires.
Re-position the RF sensor cover and solder.
NOTE: the above voltages can be measured as explained above and if the readings are correct, no adjustment is
necessary (the sensors are pre-adjusted before being installed).
INPUT
SIDE
TRIMMER
OUTPUT
SIDE
TRIMMER
