Service manual

Perform the following procedures in the
sequence indicated.
NOTE
Some of the following screens may vary depending
upon the radio under test and the version of radio
service software you are using. Refer to your radio
service software user’s guide.
C. Reference Oscillator Alignment
Adjustment of the reference oscillator is critical for
proper radio operation. Improper adjustment will result
not only in poor operation, but also in a misaligned
radio that will interfere with other users operating on
adjacent channels. For this reason, the reference
oscillator should be checked every time the radio is
serviced. The frequency counter used for this proce-
dure must have a stability of 0.1 ppm (or better).
1. From the SERVICE MENU, press F2 to select the
TRANSMITTER ALIGNMENT MENU.
2. Press F2 again to select the REFERENCE
OSCILLATOR alignment screen. See Figure 4.
3. Press Tab (or Enter or Return) to select a fre-
quency field (starting with the highest frequency
shown). Then, press F6 to key the radio. The
screen will indicate that the radio is transmitting.
4. Measure the transmit frequency on your service
monitor.
5. Use the UP/DOWN arrow keys to adjust the refer-
ence oscillator softpot value. See Table 10.
6. Press F6 again to dekey the radio.
7. Press F8 to program the new softpot value.
8. Repeat steps 3-7 for the remaining frequencies.
9. Press F10 once to return to the TRANSMITTER
ALIGNMENT MENU, or press F10 twice to return
to the SERVICE MENU.
13
MOTOROLA Radio Service Software
ASTRO Model: H04UCH9PW7AN
MAIN:SERVICE:TX ALIGN:REF OSC
Use UP/DOWN Arrows To Adjust Softpot.
F1
HELP
F2 F3 F4 F5 F6
TOGGLE
PTT
F7 F8
PROGRAM
VALUE
F9 F10
EXIT
REFERENCE OSCILLATOR
Frequency Current Value
869.9875 150 New Softpot Value ....................150
Transmitter........On
0
Min
255
Max
Figure 4. Reference Oscillator Alignment Screen
Band Target
VHF ±150Hz
UHF ±150Hz
800MHz ±150Hz
Table 10. Reference Oscillator Alignment