Theory of Operation: Transceiver Board 3-3
3.1 Transceiver Board
The transceiver (XCVR) board performs the transmitter and receiver functions necessary to translate
between voice and data from the VOCON board and the modulated radio-frequency (RF) carrier at
the antenna. The transceiver board contains all the radio’s RF circuits for the following major
components:
• Receiver
• Transmitter
• Frequency Generation Unit (FGU)
Figure 3-2 illustrates the VHF transceiver board block diagram, Figure 3-3 and Figure 3-4 illustrates
the UHF1, UHF2 and 7/800 transceiver block diagrams.
Figure 3-2. Transceiver (VHF) Block Diagram (Power and Control Omitted)
FGU
Transmitter
Receiver
SP3T
Atten
GPS
2nd
LO
Digital
RF Atten
SP3T Rf Switch
coupler
Rev
Power
Detector
Log
Amp
FET
VHF
TRIDENT IC
LOGIC
EXPANDER
LOOP
FILTER
PRESCALAR
BUFFER
RX SSI Data
16.8MHz
BUFFER
PRE
BUFFER
÷
2
TX LO
RX LO
TX
BUFFER
VHF TX
VHF TX
VHF RX
*
16.8MHz
RX SSI Clock
RX SSI Frame Sync
Indicates Sub-shield
VHF LNA
Mixer
Harmonic
Filter
Driver
Amplifier
*
Abacus
To Next Page
Loading...
Need help?
General
