Adjustments
HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual 7-29
Audio output
q Set up the equipment as for the sensitivity test (see page 7-28, Sensitivity
and (S+N)/N ratio).
q Connect an oscilloscope in parallel to the AC voltmeter across the audio
output (loudspeaker).
q Increase the volume control and check the audio output exceeds 12 V PP at
the onset of clipping displayed on the oscilloscope.
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For this test it is advisable to replace the loudspeaker with an 8 Ω, 5 W
resistor.
Selectivity (USB operation)
q Set up the equipment as for the sensitivity test (see page 7-28, Sensitivity
and (S+N)/N ratio) but with the RF gain off (test channel 20 for 2 to
26.5 MHz PA [1 08-04963] or test channel 29 for 2.25 to 30 MHz PA
[1 08-05237]).
q Set the signal generator output to 0.5 µV PD (−113 dBm).
q Take note of the audio output reference level on the AC meter.
q Monitor the signal generator using a frequency counter and adjust the
frequency to −1 kHz and then to +4 kHz from SCF (USB).
q Increase the signal generator to 0.5 mV (−53 dBm) and check that the audio
output is less than the reference level at both frequencies.
Clarifier operation
q Set the signal generator frequency 1 kHz above the SCF of the selected
channel (1 kHz below for LSB).
q Connect the output to the antenna socket.
q Set the output to any level between 0.4-10 µV PD. The RF gain can be on or
off.
q Select Clarifier mode and check the audio frequency changes with rotation
of the Select knob in a clockwise and counter-clockwise direction.
q Check that the marker on the display moves left and right, and that pips are
heard at the limits of each end of the control.
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