Azimuth Check; Index Burst Check - Panasonic JU-3 3 Series Service Manual

4.6 Azimuth Check
1. Insert an alignment diskette.
2. Step to track 40.
3. Synchronize oscilloscope on IX (-INDEX), and set time base to 20 ms/division (DAD) or to 0.5 ms/division (CE).
4. Connect one probe to T1 and the other to T2. Ground the probes to GND and AG. Set inputs to AC Add, and
invert one channel. Set vertical deflection to
5
mV/division (DAD). or to
0.1
mV/division (CE).
5. Measure as shown in Fig. 4.4.
6. Check that the measured value is within ± 24 minutes.
B C
A
Azimuth O waveforms
B
c
c
D
A
B
A
D
If B
>
C If B
<
C
B - C
@
@:30' (CE)
Azimuth= B _ D x
A
15 , (DAD)
C- B @ @:30• (CE)
Azimuth=
c:A
x
A
15 , (DAD)
Fig. 4.4
Azimuth Waveforms
4. 7 Index Burst Check
1. Insert an alignment diskette.
2. Step to track 40.
3. ·Synchronize oscilloscope on IX (+ INDEX), and set time base to 20 ms/division (DAD).
4. Connect one probe to Tl and the other to T2. Ground the probes to GND and AG. Set inputs to AC Add, and
invert one channel. Set vertical deflection to 2 mV/division (DAD).
5. Check that timing between oscilloscope start and first data pulse is 3 ± 1.7 ms (DAD).
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