Raymarine Ray 106 User Manual page 33

10 Poor or no modulation
11 Deviation of transmit frequency
12 PLL output frequency or level
Table 5-4 TROUBLESHOOTING CHART (Continued)
good, then check the triple Pi type network components
(C1 - C4 and L1 - L4 ) and antenna switching diode
(D112). If not good, then check the voltage level
outputs of the drive amplifiers Q5 and Q6 as well as the
associated circuitry.
b. Check power control circuit (IC2 and/or associated
circuitry)
a. Defective microphone or microphone connection.
b. Defective IC103, IC102 and/or its associated
components.
a. Check VCO output frequency at pin 8 of PLL IC3,
PLL phase detector output at pin 16, 15 of PLL IC3,
Q11, Q12 and associated circuitry.
b. Check 12.8 MHz crystal (XTL1).
a. Check frequency of 12.8 MHz crystal (XTL1).
b. Check the frequency output at pin 8 of IC 3 and verify
the transmit frequency.