
256
Receiver Fault Finding
TP9100 Service Manual
© Tait Electronics Limited
May 2005
Task 5 —
Check Biasing
of IF Amplifier
If the lock status is normal, check the biasing of the IF amplifier.
1.
Remove the
IF IQ BOT
can.
2.
Check all components around
Q404
of the IF amplifier
(see
3.
Check the 3 V supply voltage at
L419
; use the measurement point
shown in
.
4.
Also check the amplifier bias conditions. First measure V
c
between
the collector of
Q404
and ground (see
).
5.
Secondly, check I
c
. To do so, unsolder and raise one terminal of
L419
(tombstone position) (see
), connect a multimeter
between this terminal and the pad for the terminal, and measure the
current.
6.
reveal no fault, go to
.
If there is a fault, repair it and go to
.
7.
Recalibrate the receiver using the calibration application.
8.
Confirm the removal of the fault and go to
. If the repair failed, go to
.
V
c
: 2.0±0.2V
I
c
: 1.8±0.5mA
Summary of Contents for TP9100
Page 1: ...TP9100 portables Service Manual MPA 00005 01 Issue 1 00 May 2005 ...
Page 4: ...4 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 10: ...10 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 74: ...74 Circuit Descriptions TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 78: ...78 TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 100: ...100 General Information TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 126: ...126 Disassembly and Reassembly TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 148: ...148 Interface Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 158: ...158 Power Supply Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 250: ...250 Transmitter Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 268: ...268 Receiver Fault Finding TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 294: ...294 Spare Parts TP9100 Service Manual Tait Electronics Limited May 2005 ...
Page 298: ...298 Antenna Identification Chart TP9100 Service Manual Tait Electronics Limited May 2005 ...