Technical Manual

10-34
Chart 35. 800 MHz Transmitter RF
No/Low Power
Replace
Ant Switch
YES
NO
Check
Continuity at
Ant. Switch
NO
BADBAD
GOOD
GOOD GOOD
BAD
Check L102,
L105, C114,
C101, C108
Replace U501
Go to VCO
Chart C.34
Go to DC Switch
Chart C.35
NO
YES
Check E1, E2,
E3, E4, J3
Check Q502
& R509
Go to VCO
Chart #5B
Replace U502
Check R507,
R508
NO
YES
YES
NO
NO
YES
NO
YES
NO
YES
YES
YES
NO
NO
YES
YES
NO
NO NO
GOOD
YES
NO
Check U503
D/A IC
VDC
U502-3
0.37 VDC
U504-A3
VDC
U502-1
VDC
U502-2
VDC
Base Q501
VDC
U502-5
VDC
U504-E4
VDC
U504-E3
VDC
U503-B5
Check: U504,
CR501, R505,
C503, R503,
R506
OHM\
Q501
VDC
U504-C1
Check U504
ALC IC
Check U503
D/A IC
VDC
at
Q503
RF
Input Drive
U502-1
>1dB
B+ VDC
U502-4
Check Continuity
Between U504-B3
& J1-20
Change ALC
U504
YES
YES
NO
See Chart C.32
FGU Unlock
Check U503
D/A IC
Check R501
MAEPF-26045-O
YES
YES
NO
NO
NO
5 VDC
U504-B2
VDC
Lock Det
Cath.
CR502
VDC
U503-E2
VDC
U504-B3
Check RF @
RF Connector
J2
Check
Continuity
across
U501
RF
Input Drive
U502-1
>1dBm
TX
Current
>500 mA
YES
NO
Check
L101