Clarifier Operation; Noise Limiter Operation; Transmitter Performance Checks; Frequency Check - Codan X-2 Service Manual

Adjustments 7-14

7.12.5 Clarifier Operation

Set the Signal Generator frequency 1 kHz above the SCF of the selected
channel (1 kHz below for LSB) and connect the output, set to any level
between 0.4 µV and 10 µV PD, to the selected Antenna socket.
Check the audio frequency changes with rotation of the Clarifier in a
clockwise and counter-clockwise direction. Check also that pips are heard at
the limits of each end of the control.

7.12.6 Noise Limiter Operation

Set the Signal Generator frequency 1 kHz above the SCF of the selected
channel (1 kHz below for LSB) and connect the output, set to 0.4 µV PD,
via a Tee piece to the selected Antenna socket.
To the unoccupied socket of the Tee piece add a BNC to Two-Terminal
adaptor. Connect the output of a Square-wave Generator via a 100 pF
capacitor to the adaptor. Set the Square-wave Generator frequency to a
100 Hz and the output to 5 V peak to peak.
The Noise Limiter is normally ON and the signal produced by the Signal
Generator should be clearly heard over the interfering signal from the
Square-wave Generator.
When the Noise Limiter is switched off, by shorting A to E on N/L test point
on the Rx/Exciter & Control PCB, the noise from the Square-wave
Generator should swamp the wanted signal from the Signal Generator. This
test will verify the Noise Limiter is functioning correctly.

7.13 Transmitter Performance Checks

7.13.1 Frequency Check

Check as detailed in the Frequency Adjustment Section 7.9.
X-2 Technical Service Manual
Publication No: 15-02047