Motorola ASTRO SPECTRA Service Manual

6881076C20-E February 3, 2003
Radio Alignment Procedure: ASTRO Digital Spectra and Digital Spectra Plus Tuner Software 6-13
Figure 6-11. Typical Softpot Adjustment Screen
Adjusting the softpot value sends information to the radio to increase (or decrease) a voltage in the
corresponding circuit. For example, left-clicking the UP spin button (
▲) on 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.
Digital Spectra only: Each Digital Spectra tuning screen contains a Program button. Pressing the
Program button sets only the softpot value associated with the currently selected frequency, so it is
necessary to press the Program button after tuning each softpot at each and every frequency.
Digital Spectra Plus only: Each Digital Spectra tuning screen contains a Program All button.
Pressing the Program All button sets all softpot values shown on the screen at the same time, which
makes it possible to first adjust all the softpot values and then press the Program All button to set
the values before leaving a screen. Pressing the Program All button more than once has no
adverse effect on the new values.
Perform the following procedures in the sequence indicated.
NOTE: Some of the following screens may vary depending on the radio under test and the version of
tuner software you are using. Refer to the software’s on-line help.

Motorola ASTRO SPECTRA Specifications

General

Frequency Range	136-174 MHz, 403-470 MHz
Number of Channels	Up to 255
Channel Spacing	12.5 kHz, 20 kHz, 25 kHz
Modulation	FM
Operating Temperature	-22°F to +140°F (-30°C to +60°C)