SECTION 1 ELECTRICAL ADJUSTMENTS
TUNER UNIT SECTION
� Use the following equipment for the electrical adjustment. Equipment 1 Monitor TV (XVM-6100, etc.) 2 Spectrum analyzer 3 TV signal generator 4 Digital voltmeter 5 Oscilloscope 6 Audio analyzer 7 DC power supply 8 Frequency counter Equipment Connections Connect the test equipment as shown in the figure below (unless otherwise instructed) and perform the adjustment.
DC power supply
TRAP Adjustment Procedure: 1. With the Power off, input the output of TG to TP30 (with DC cut by a capacitor (0.01 µF)). 2. Connect a spectrum analyzer to TP31 (with DC cut by a capacitor (0.01 µF)). 3. Adjust T1 so that the waveform peak is 40.9 MHz ± 50 Hz. 4. Adjust T2 so that the waveform peak is 31.9 MHz ± 50 Hz. 5. After this adjustment, open TP30 and TP31. (Disconnect the spectrum analyzer.)
T1= 40.9 MHz T2= 31.9 MHz
TV SG
ANT IN set
RF out
POWER (CN4)
VCO Adjustment Procedure: 1. No connection to ANT IN. (no signal state) 2. Connect a resistor (10 k�) between TP33 and +9 V (TP35). 3. Connect a spectrum analyzer to TP34 (with DC cut by a capacitor (0.01 µF)). 4. Adjust T3 so that the waveform peak is 38.9 MHz ± 1 kHz. 5. After this adjustment, open TP34. (Disconnect the spectrum analyzer.)
Setup during Adjustment Use the video signal obtained from the TV signal generator as the alignment signal, and check that this signal is within video output signal standards.
white (approx. 100%)
0.7 V 0.3 V 0.3 V red horizontal sync. signal burst signal (flat)
38.9 MHz
AGC Adjustment Procedure: 1. Set the TV SYSTEM switch to 1. 2. Input a color bar signal of E8ch (196.25 MHz) and 66 dBµV (75 � OPEN). 3. Connect the digital voltmeter to TP42. 4. Adjust VR1 so that reading on the digital voltmeter is 6.0 ± 0.1 V. AFT Adjustment Procedure: 1. Input a color bar signal of E8ch (196.25 MHz) and 74 dBµV (75 � OPEN). 2. Connect the oscilloscope to TP102. 3. Adjust T3 untill the waveform on the oscilloscope is 2.5 Vp-p.
Color bar signal from TV signal generator
Connection points: Refer to page 4. Adjustment points: Refer to page 4.
2.5 Vp-p 0V
Note: Small peaks (dips) coming out from the top of the waveform are unacceptable.
