Chapter 3 Basic Theory of Operation
This chapter discusses the basic operational theory of the ASTRO APX 2000/ APX 4000 radio. The
ASTRO APX 2000/ APX 4000 radio, which is a single-band synthesized radio, is available in the
following frequency bands.
• VHF (136–174 MHz)
• UHF1 (380–470 MHz)
• UHF2 (450–520 MHz)
• 700/800 MHz (764–870 MHz)
• 900 MHz (896–941 MHz).
And the ASTRO APX 2000 M1.5, APX 4000Li M1.5 and APX 4000Li M2 is available in the following
frequency bands.
• VHF (136–174 MHz)
• UHF1 (380–470 MHz)
• UHF2 (450–520 MHz)
• 700/800 MHz (764–870 MHz)
All ASTRO APX 2000/ APX 4000/ APX4000 Li radios besides the radios with 900 MHz are capable
of analog operation (12.5 kHz or 25 kHz bandwidths), ASTRO mode (digital) operation (12.5 kHz
only), X2-TDMA mode (25 kHz only) and Phase 2 TDMA mode (12.5 kHz only).
For radios with 900 MHz, they support analog operation (12.5 kHz only), ASTRO mode (digital)
operation (12.5 kHz only), and Phase 2 TDMA mode (12.5 kHz only).
NOTE: The APX 2000 M1.5, APX 4000Li M1.5 and APX 4000Li M2 radio do not support any Global
Positioning System (GPS), Bluetooth, MACE and Accelerometer functions. As such,
disregard all references to the functions mentioned above in
Operation".
"Chapter 3 Basic Theory of