Transceiver (Rf) Section; Figure 8-4. Vhf Transceiver (Rf) Board Overall Circuit Schematic - Motorola ASTRO XTSTM 4000 Detailed Service Manual

Schematics, Board Overlays, and Parts Lists – VHF: Transceiver (RF) Section
8.4

Transceiver (RF) Section

XCVR_SWB+
RAWB+
FUB+
VSW1
TXTD
TXCK
TXFS
LOCK
F168
RSTL
MOSI
SPCK
USEL
ABCS
RXCK
RXFS
RXDO
SH01 SHIELD
(RECEIVER BACK-END)
SH02 SHIELD
(RECEIVER LOW-NOISE
AMPLIFIER & RF POST FILTER)
6871620L01-C
D1
MBRM140T3
U1
XB+ E5
LP2989
BK1005HM471
LP2989IMMX-5.0
4 5
INPUT OUTPUT
8 7
SHUTDOWN ERROR
6
SENSE
1 2
BYPASS NC
C12 C11
10uF 0.10uF
C13
.01uF
2.2 uF min.
TXH
V5A V3A
V5A
FGU
V3A
XB+ VSW1 FUB+ RAWB+
SCEN
TXTD
SSTD
TXCK
SSCK
TXFS
SSFS
LOCK
LOCK
MOSI
DATA
SPCK
CLK A200,A300
USEL
CSX
MOSI
SPCK
USEL
V5A V3D
1000pF V5A
C1719
V3D
SPCK
PC
MOSI
PD
ABCS
PE
CKO LO
RXCK
CLKOUT
RXFS
FS ADC
RXDO
DOUTA
RX_BE
A500
SH05 SHIELD
SH03 SHIELD
(FGU (SYNTHESIZER 2))
(RECEIVER RF PRE-FILTER)
SH04 SHIELD
SH06 SHIELD
(RECEIVER MIXER & IF FILTER)
(TRANSMIT PRE-DRIVER STAGE)
VSW1_filtered
XCVR DC Regulators
V5A V5R VSW1
L10
100uH
Q4
NTR1P02T1
C14 C10 C30
R1709
NC 10uF 1000pF 10uF
100K
R1708
100K
TXH
RAWB+ XB+ V5A V5A
RAWB+
TX_ALC
XB+
V5A
POUT
TXRF TXRF
NC TXINH
RSTL
RXLO MOSI
SPCK TX5V
A100
USEL VAR2
F168 VAR3
RXLO
V5R
FREF V5R LOIN
DAC2
RX_FE
A400
RXIF
RXIF
RXIF RXIN
SH07 SHIELD SH09 SHIELD
(HARMONIC FILTER & (FGU (SYNTHESIZER 1))
ANTENNA SWITCH)
SH08 SHIELD SH10 SHIELD
(TRANSMIT POWER STAGE) (FGU (VCO))
D3
MBRM140T3
V3A
3
VEN
1 5
VIN VOUT
4
BYPASS
C25
1.0uF
C27 C28
1.0uF 1000pF
U3
C26 LP3985
.01uF
D2
MBRM140T3
V3D
3
VEN
1 5
VIN VOUT
4
BYPASS
C15
1.0uF
C17 C9
1.0uF 1000pF
U2
C16 LP3985
.01uF
V5A
TXRF
ANT ANT
RXRF
SW_FL
TX5V
A700
VAR3
SH11 SHIELD
(RECEIVER 2ND LO VCO)

Figure 8-4. VHF Transceiver (RF) Board Overall Circuit Schematic

8-5
May 28, 2008