This machine uses the audio circuit quasi- separation function of PIF / SIF IC AN5179K, and the addition of NICAM (NICAM) stereo decoder circuitry to provide the equivalent of CD quality audio sound .aVxservice manual download site

The aircraft audio circuit as shown in the drawings , sound IF signal is amplified by the Q105 , X106 filtered by a SAW filter , to the IC101 (AN5179K) 23 feet, rushed all the way sound IF AGC circuit , complete the automatic volume control ; another sent all the way to the mixer detector circuit , that is 31.5MHz/32.0MHz/32.5MHz/33.5MHz sound IF signal and after the first phase lock control switch signal bully APC circuit 38MHz input frequency , the mixer output from IC1015 pin the second difference frequency sound signals 6.5MHz/6.0MHz/5.5MHz/4.5MHz, and then the band-pass filter X201 ~ X205 select a second sound IF signal , were sent to IC20111, 12,14,15 feet, complete a variety of sound features, and all the way through IC201 control output signal sent IC10130 feet by 13 feet ; through internal processing into analog audio signals output by the 28 feet by R1226, C2129 amplified to the Q2105 , L, R two -channel after the plug- B5, F5 sent IC22027, 10 feet. Another difference frequency signal IC1015 second sound output from the foot also sent NICAM (NICAM) decoding circuit , completed NICAM decoding function , the solution out of the L, R signals are sent to IC22025, 12 feet. The two -way L, R signal by ICE after switching from 8,11 internal switch output pin via plug F6, B6, B3, C3, IC3001 conversion , and then plug C1, A2, IC2401 to headphones and speakers , respectively .aVxservice manual download site