Motorola ASTRO Digital Spectra Plus - Figure 4-1. VCO Block Diagram - VHF Band

September 5, 2008 6881076C25-E
4-14 Troubleshooting Procedures: VCO Procedures
Figure 4-1. VCO Block Diagram – VHF Band
RANGE AUX1 AUX2
RX1 >8Vdc >8Vdc
RX2, TX1 <1Vdc >8Vdc
TX2 >8Vdc <1Vdc
TX3 <1Vdc <1Vdc
GPW-5867-O
VCO
AUX 1
AUX 2
J601-11
J601-9
SF 8.6
J601-12
9.6
J601-2
PIN DIODE
DRIVERS
BIAS
BIAS
J601-3
J601-4
+SL
-SL
MOD
J601-10
Q3645
VCO SUBSTRATE
LOW
PASS
FILTER
PAD
Q3675
J3642
PAD
PAD
BIAS
RX INJECTION TO
RECEIVER FRONT
END > + 19dBm
SYNTHESIZER
FEEDBACK
J601-1
K9.4
5V
REG.
U3675
K9.4
5V
U3676
Q3676
J601-5
J3641
TX INJECTION TO
PA > +9dBm
_
.
.
2