Mhz Crystal Oscillator Adjustment (Vc-188 Board) - Sony CCD-TRV32 Service Manual

6. 28MHz crystal oscillator adjustment
(VC-188 board)
Purpose : Adjusts 28MHz crystal controlled oscillation
for synchronizing clock.
Adjustment error : Loss of synchronization or loss of color.
Subject Not required
IC201 %¢ pin
Measurement Point
Measuring Instrument Frequency counter
Adjustment Page F
Adjustment Address 3D
4433618.75 ± 17Hz (PAL)
Specification
3579545 ± 17Hz (NTSC)
Adjustment procedure:
Order Page Address
1 6 00
2 F 3D
3 F 3D
4 6 00
Reference: Conversion between the hexadecimal
number and decimal number.
In some adjustment items, data appears in hexadecimal numbers on
the DDS display or on the adjustment remote commander.
Maintenance engineers are expected to convert the displayed
hexadecimal numbers to the corresponding decimal numbers using
Hexadecimal-decimal Conversion Table
Lower digit of
hexadecimal 0 0 0
Upper digit
of hexadecimal
0
0
16
1
2 32
3 48
4 64
80
5
96
6
112
7
128
8
144
9
160
A ( )
A
1
176
B ( )
b
C ( ) 192
c
D ( ) 208
d
224
E ( )
E
240
F ( )
F
Note : The characters shown in the parenthesis ( ) shown the display on the adjustment remote commander.
(Example) If the DDS display or the adjustment remote commander shows BD (
Because the upper digit of the adjustment number is B (
"189" of 1 and 2 in the above table is the corresponding decimal number.
Data
01 After setting the data, press the PAUSE button. (Preparation)
Change the data using PLAY, STOP buttons until the frequency satisfies the specification.
Press the PAUSE button.
00 After setting the data, press the PAUSE button. (End)
1 2 3 4 5
1 2 3 4 5
17 18 19 20 21
33 34 35 36 37
49 50 51 52 53
65 66 67 68 69
81 82 83 84 85
97 98 99 100 101
113 114 115 116 117
129 130 131 132 133
145 146 147 148 149
161 162 163 164 165
178 179 180 181
177
193 194 195 196 197
209 210 211 212 213
225 226 227 228 229
241 242 243 244 245
Procedure
the following conversion table.
Make a required calculation described in each adjustment item. Then
re-convert the result of calculation back from the decimal numbers
to the corresponding hexadecimal numbers using the following
conversion table.
6 7 8 9 A
(
A
6 7 8 9 10
22 23 24 25 26
38 39 40 41 42
54 55 56 57 58
70 71 72 73 74
86 87 88 89 90
102 103 104 105 106
118 119 120 121 122
134 135 136 137 138
150 151 152 153 154
166 167 168 169 170
182 183 184 185 186
198 199 200 201 202
214 215 216 217 218
230 231 232 233 234
246 247 248 249 250
b
), and the lower digit is D (
6-12
2
B C D E
) ( ) ( ) ( ) (
)
b c d E
11 12 13 14
27 28 29 30
43 44 45 46
59 60 61 62
77 76 77 78
91 92 93 94
107 108 109 110
123 124 125 126
139 140 141 142
155 156 157 158
171 172 173 174
187 188 189 190
203 204 205 206
219 220 221 222
235 236 237 238
251 252 253 254
bd
);
d
), the meeting point
F
( )
F
15
31
47
63
79
95
111
127
143
159
175
191
207
223
239
255