Philips VR120 Service Manual page 95

Determining the deviation (in ppm):
f ..... measured frequency
mess
f ........target frequency (8192,00 Hz)
nom
Deviation = 1x106 x (f
mess
Determining the correction value for Step 53:
Correction value = Deviation / 0.763 + 128 (round off to whole
number)
The calculated correction value must be between 0 and 255
(change quartz otherwise), and must be entered in Step 53
and saved.
This step can either be exited by performing a main power
source reset, after which the service program must be
entered again or by pressing any key on the set, before
step 53 can be entered.
Example:
f =8191.97Hz f
mess
6
Deviation = 1x10 x (8191.97 - 8192.00) / 8192.00 = -3.662
Correction value = -3.662 / 0.763 + 128 = 123.20 = 123
8.8.2 Inputing the clock correction
Before carrying out step 53, the correction value must be
established in step 99.
By pressing the SELECT key whilst step 53 is flashing, the
display shows, for instance (128 is the default value of an
empty EEPROM):
Using the numerical keys of the remote control, the
established correction value from Step 99 is entered as a 3-
digit number (value must be between 0 and 255).
After pressing the OK key on the remote control, the entered
code is stored, the display shows OK for approx. 3 seconds
and then the stored value in decimal format.
In case of an invalid entry (value >255), the activation of the
OK key causes the content of the last stored value to be
displayed and OK does not appear in the display.
To leave the step press Select.
- f ) /
nom fnom
=8192.00Hz
nom
Electrical alignments VR120 8. GB 95