Service manual

G. Front-End Filter Alignment (VHF/UHF Only)
NOTE
This procedure is only required for tuning the front-
end filter varactors in the VHF and UHF models.
The 800MHz models utilize a fixed front-end filter.
1. From the SERVICE MENU, press F3 to select the
RECEIVER ALIGNMENT MENU.
2. Press F2 to select the FRONT END FILTER
ALIGNMENT screen. The screen will indicate the
receive frequencies at which the filter is to be
aligned. See Figure 8.
3. Press Tab (or Enter or Return) to select a fre-
quency field.
4. Set the RF test generator to the first receive
frequency +150Hz. Set the RF level at the
radio standard antenna port to 4.0µV with no
modulation.
5. Adjust the UP/DOWN arrow keys to obtain a peak
value in the RSSI (receive signal strength indica-
tor) field. Note F4 must be pressed to obtain each
RSSI reading after adjustment.
6. Press F8 to program the new softpot value.
7. Repeat steps 3-6 for the remaining frequencies.
8. Press F10 once to return to the RECEIVER
ALIGNMENT MENU, or press F10 twice to return
to the SERVICE MENU.
17
MOTOROLA Radio Service Software
ASTRO Model: H04UCH9PW7AN
MAIN:SERVICE:RX ALIGN:FE FL
Use UP/DOWN Arrows To Adjust Softpot.
FRONT END FILTER ALIGNMENT
Current
Frequency
Value New Softpot Value RSSI. . . .0
450.02500 0 0
465.22500 0 0
475.22500 0 0
484.97500 0 0
500.27500 0 0
511.97500 0 0
519.97500 0 0
F1
HELP
F2 F3 F4
READ
RSSI
F5
F6 F7 F8
PROGRAM
VALUE
F9 F10
EXIT
0
Min
255
Max
Figure 8. Front-End Filter Alignment Screen