PRACTICAL SERVICE FIGURE
1. Clock Frequency Check Settings: � Test point: TP2 (CLK IC770 pin30) Method: Set to MW 1602kHz and check that the test point becomes 2052kHz±45Hz (EZ). 2. MW VT Check Settings: � Test point: TP1 (VT) Method: Set to MW 1602kHz and check that the test point is less than 8.0V. Then set to MW 531kHz and check that the test point is more than 0.6V. 3. MW IF Adjustment Settings: � Test point: TP5, TP6 L772 .............................................. 450kHz 4. MW Tracking Adjustment Settings: � Test point: TP5, TP6 � Adjustment location: L981 Method: Set to MW 999kHz and adjust L981 so that the test point becomes maximum. 5. FM VT Check Settings: � Test point: TP1 (VT) Method: Set to FM 87.5MHz, 108.0MHz and check that the test point is more than 0.5V (87.5MHz) and less than 8.0V (108.0MHz). 6. LW VT Adjustment Settings: � Test point: TP2 (VT) � Adjustment location: L942 Method: Set to LW 144kHz and adjust L942 so that the test point becomes 1.3V±0.05V. Then set to LW 290kHz and check that the test point is less than 8.0V. 7. LW Tracking Adjustment Settings: � Test point: TP5, TP6 � Adjustment location: L941 .............................................. 144kHz TC942 ........................................... 290kHz Method: Set up TC942 to center before adjustment. The level at 144kHz is adjusted to MAX by L941. Then the level at 290kHz is adjusted to MAX by TC942. 8. DC Balance/Mono Distortion Adjustment Settings: � Test point: TP3, TP4 � Adjustment location: L771 � Input level: 54dB Method: Set to FM 98.0MHz and adjust L771 so that the voltage between TP3 and TP4 becomes 0V±0.04V. Next, check that the distortion is less than 1.3%.
< TUNER SECTION >
< FM SECTION > IHF Sensitiviy: (THD 3%) Less than 14dB (at 88.0/98.0MHz) Less than 16dB (at 108.0MHz) Distortion: (input 66dB) Stereo separation: Intermediate frequency: < MW SECTION > Sensitivity: (S/N 20dB) Distortion: (input 74dB) < LW SECTION > Sensitivity: (S/N 20dB) Distortion: (input 80dB) Less than 76dB (at 153kHz) Less than 71dB (at 198kHz) Less than 69dB (at 279kHz) Less than 3% (at 198kHz) More than 16dB (98.0MHz) 10.7MHz Less than 1.5% (98.0MHz)
Less than 60dB (at 603kHz) Less than 58dB (at 999/1404kHz) Less than 2% (at 999kHz)
