Adjustments
HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual 7-21
Frequency adjustment
1 08-04962 and 08-05322
All the channels are synthesised and locked to the 7304 kHz reference crystal (Z3)
oscillator. The divided reference crystal oscillator (7304 kHz divided by 16)
provides the local oscillator to the modulator and demodulator in USB mode.
Therefore, it is only necessary to adjust the reference frequency for all channels on
USB.
An additional divided crystal oscillator (1814 kHz divided by 4) provides the local
oscillator to the modulator and demodulator in LSB mode.
Frequency adjust USB
Adjusting the frequency of the USB
q Select test channel 18 (2.0 to 26.5 MHz PA) or test channel 28 (2.25 to
30 MHz PA). Both channels are 26.5 MHz.
q Remove the coaxial connector from J1 on the Rx/Exciter PCB (removing
the exciter output to the PA).
q Connect a frequency counter to Exciter output J1.
q Press the Tune button on the control panel.
q Adjust trimmer C116 [1 08-04962] or C115 [1 08-05322] (reference
crystal adjust) to a frequency of 26.5 MHz ±5 Hz.
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Allow at least five minutes from switch on before adjusting the frequency.
Frequency adjust LSB
Adjusting the frequency of the LSB
q Adjust frequency in the USB (see page 7-21, Frequency adjust USB).
Remain on the same channel and leave the frequency counter connected.
q Select LSB.
q Press the Tune button on the control panel.
q Adjust C243 for 26.5 MHz ±5 Hz.
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