Figure 3-7. Transmitter (Uhf1/Uhf2) Block Diagram; Figure 3-8. Transmitter (Vhf) Block Diagram - Motorola APX 3000 Basic Service Manual

Basic Theory of Operation: Analog Mode of Operation
3.2.2 Transmitting
When the radio is transmitting, microphone audio is digitized and then processed by the DSP and
sent to the Trident IC (see
processes the SSI data for application to the voltage controlled oscillator as a modulation signal.
TX Buffer Amp
TX Driver Amplifier
TX VCO
RX
VCO
RF Switch Matrix
TX Buffer Amp
RF Switch Matrix
Figure 3-7,
Transmitter Final
FET UHF1/UHF2
Loop Filter

Figure 3-7. Transmitter (UHF1/UHF2) Block Diagram

TX Driver Amplifier
Transmitter Final
FET VHF
Loop Filter
TX VCO
RX
VCO

Figure 3-8. Transmitter (VHF) Block Diagram

Figure 3-8 and Figure
Antenna
Switch
Harmonic
LP Filter
TO RX
Trident IC
Synthesizer
Antenna
Switch
Harmonic
LP Filter
TO RX
Trident IC
Synthesizer
3-9) via the SSI interface. The Trident IC
Log Amp Power Detector
Digital RF Attenuator
Directional
Coupler
Reverse Power
Detection
GPS
Ref. Oscillator
Log Amp Power Detector
Digital RF Attenuator
Directional
Coupler
Antenna Connector
Reverse Power
Detection
GPS
Ref. Oscillator
3-5
Antenna Connector