15
Adjusting the softpot value sends information to the radio to increase
(or decrease) a dc voltage in the corresponding circuit. For example,
pressing the UP arrow key at the Reference Oscillator screen instructs
the radio’s microcomputer to increase the voltage across a varactor in
the reference oscillator, which increases the frequency.
In ALL cases, the softpot value is just a relative number corresponding
to a digital-to-analog (D/A) generated voltage in the radio.
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.
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 procedure must have a stability of 0.1
ppm (or better).
1. From the SERVICE MENU, press
B
to select the TRANSMITTER
ALIGNMENT MENU.
2. Press
B
again to select the REFERENCE OSCILLATOR alignment
screen. See Figure 4.
Figure 4 Reference Oscillator Alignment Screen
3. Press
P
(or
Z
or [RETURN]) to select a frequency field
(starting with the highest frequency shown). Then, press
F
to
key the radio. The screen will indicate that the radio is
transmitting.
MOTOROLA Radio Service Software Use UP/DOWN Arrows To Adjust Softpot.
ASTRO Model: H09UCH9PW7AN
MAIN:SERVICE:TX ALIGN:REF OSC
REFERENCE OSCILLATOR
--------------------
Frequency Current Value
--------- -------------
869.9875 150 New Softpot Value.....150
Transmitter..On
0 255
MIN |----+----+----+----+----+----+----+----+----+----+----+----| MAX
F1 F2 F3 F4 F5 F6 F7 F8 F9 F10
HELP TOGGLE PROGRAM EXIT
PTT VALUE
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