Sharp XL-3700 Service Manual - Page 9

TUNER SECTION ADJUSTMENT XL-3600 XL-3700/C fL: Low-range frequency fH: High-range frequency • AM IF/RF Signal generator: 400 Hz, 30%, AM modulated • FM Mute Level Signal generator: 1 kHz, 40 kHz dev., FM modulated Frequency Frequency Display AM IF AM Band Coverage AM Tracking 450 kHz - 990 kHz 1,620 kHz 522 kHz 990 kHz Setting/ Instrument Adjusting Connection Parts T351 *1 (fL): T306 *2 1.1 ± 0.1 V (fL): T302 *1 *1. Input: Antenna, Output: Speaker Terminal *2. Input: Input is not connected, Output: TP301 • Setting the Test Mode Keeping the FF/FWD button and MEMORY/SET button pressed, turn on POWER. Then, the frequency is initially set in the memory as shown in Table. Call it with the VOLUME UP/ DOWN button to use it for adjustment and check of tuner circuit. Frequency Display 98.00 MHz (30 dBµV) 98.00 MHz Adjusting Parts VR351*1 Instrument Connection Input: SO301 Output: Speaker Terminal *1. Adjust so that an output signal appears. • Check FM VT Signal generator: 1 kHz, 40 kHz dev., FM modulated Frequency Display 87.5 MHz 108 MHz 87.5 MHz 108 MHz Check Point 2.2 V ± 0.7 V 7.3 V ± 1.0 V Instrument Connection TP301 TP301 Preset No. FM Preset No. AM 1 87.50 MHz 6 2 108.00 MHz 7 3 98.00 MHz 8 4 90.00 MHz 9 5 106.00 MHz 10 522 kHz 1,620 kHz 990 kHz 603 kHz 1,404 kHz FM SO301 ANTENNA 75 OHMS TERMINAL TUNER PWB-B1 GND AM TP301 FE301 20 IC302 VR351 FM Mute Level T351 AM IF IC303 T302 AM Tracking fL T306 AM Band Coverage fL Figure 9 ADJUSTMENT POINTS - 9 -