Sangean ATS-909X Service Manual page 26

(3) SSB function do not work
Check whether reception is normal in AM
mode.
YES
Check the oscillator frequency of TP1
whether 448KHz in LSB mode or 452KHz
in USB mode.
NO
Check the oscillator circuit Q9 and T2.
YES
Check the USB/LSB selector circuit Q10,
Q11 and Q12.
YES
Check the mix loop D9, D10, T2, R1 and
C1.
NO
Check AM receiving circuit.
NORMAL
YES
Check the circuit of Q6, Q7 and Q8.
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