Figure 3-8. Receiver Block Diagram (Uhf1/Uhf2); Figure 3-9. Receiver Block Diagram (700/800 Mhz ); Figure 3-10. Receiver Block Diagram (900 Mhz ) - Motorola APX 1000 Detailed Service Manual

Theory of Operation: Main Board
Antenna
Switch
Harmonic
Filter
Diplexer
Antenna
Harmonic
Switch
Filter
DIG_CTRL_ATTH
Diplexer
Antenna
Switch
Harmonic
Filter
Diplexer
15 dB Step
Attenuator
UHF
DIG_CTRL_ATTH

Figure 3-8. Receiver Block Diagram (UHF1/UHF2)

800
15 dB Step
Attenuator
SW SW
700

Figure 3-9. Receiver Block Diagram (700/800 MHz )

15 dB Step
Attenuator
900
DIG_CTRL_ATTH

Figure 3-10. Receiver Block Diagram (900 MHz )

UHF
Rx LO
To GPS
800
SW SW
700
To GPS
900
Rx LO
To GPS
IF Filter
ABACUS III
ΣΔ ADC
2nd
LO CLK
LO
Abacus III
IF Filter
ABACUS III
ΣΔ ADC
Rx LO
2nd
LO
LO
IF Filter
ABACUS III
ΣΔ ADC
2nd
LO CLK
LO
Abacus III
3-9
Dec.
SSI
Filter
18Mhz
CLK
Dec.
SSI
Filter
18Mhz
CLK
CLK
Abacus III
Dec.
SSI
Filter
18Mhz
CLK