Sony CCD-TRV312 Operating Instructions (primary manual), Service Manual, Page: 141 / 212

6-12
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
Measurement Point IC201
%¢
pin
Measuring Instrument Frequency counter
Adjustment Page F
Adjustment Address 3D
Specification 4433618.75
±
17Hz (PAL)
3579545
±
17Hz (NTSC)
Adjustment procedure:
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
Order Page Address Data Procedure
1 6 00 01 After setting the data, press the PAUSE button. (Preparation)
2 F 3D Change the data using PLAY, STOP buttons until the frequency satisfies the specification.
3 F 3D Press the PAUSE button.
4 6 00 00 After setting the data, press the PAUSE button. (End)
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.
Hexadecimal-decimal Conversion Table
Lower digit of
hexadecimal
Upper digit
of hexadecimal
0 1 2 3 4 5 6 7 8 9 A
(
A
)
B
(
b
)
C
(
c
)
D
(
d
)
E
(
E )
F
(
F
)
0
1
2
3
4
5
6
7
8
9
A (
A
)
B (
b
)
C (
c
)
D ( d )
E (
E
)
F (
F
)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
64 65 66 67 68 69 70 71 72 73 74 77 76 77 78 79
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
174
159
175 160 161 162 163 164 165 166 167 168 169 170 171 172 173
177
176
178 179 180 181 182 183 184 185 186 187 188 189 190 191
192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
0
1
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 (
bd
);
Because the upper digit of the adjustment number is B (
b
), and the lower digit is D (
d
), the meeting point
“189” of
1
and
2
in the above table is the corresponding decimal number.
0
2