The machine uses a main sprite can receive " RF PIP " program two TV programs. Main and sub picture with a tuner, the image placed in the video signal processing circuit simultaneously receives two RF TV. PIP part using a three manifold : main manifold ic803, for the sprite image in place , p / n color decoder , and to generate horizontal and vertical sync signals rgb / yuv switch ; the other two are ic802 and ic801, respectively, for the sprite be d / a conversion and effects processing .

 

A sprite demodulation circuit

 

1 ª± sprite sprite IF signal is demodulated sub-screen tv tuner (tuner2) sent by pip amplitude -frequency characteristics can sa801 selected frequency SAW filter , the coupling to the ic803 {33}, {34} feet . After the internal IF amplifier demodulated video video signal output from the { 22 } feet , after q802 buffer amplified by {20 } feet and then enter the ic803. Video signal output from the amplifier in the ic803 points the way to go as a control signal rfagc of { 31} pin external vr801 for rfagc adjustments. rfagc voltage output from the ic803 {29} → r824 → cn8021 → cn3031 → d112 → tuner2 agc end . { 28 } feet pip ntsc tone adjustment , the control signal from the cpu {12} feet.

sa801 (ofw6263k) to be luffing type SAW filter frequency characteristics . When the sub-screen tv signal reception pal system , ic803 {25} feet ( chroma format logical entry / exit ) output low , q801 deadline , d801 conduction , sa8011, 10 -pin parallel , constitute wideband state to meet pal relatively wide standard amplitude-frequency characteristic requirements get higher image resolution and better audio signal ; system when receiving ntsc tv signal , ic801 {25} feet high output , q801 conduction , d801 deadline , only the intermediate frequency signal from the sub-picture input pin sa8011 passband corresponding narrowed to ensure without any loss of image sharpness , image sound suppressing crosstalk .

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