Tait TP9100 Service Manual page 229

Task 7 —
If the RF output power and the supply current are skewed, the output
Power and Current
matching is suspect.
are Skewed
1.
2.
3.
Task 8 —
If the RF output power and the supply current are uniformly low at all
Power and Current
frequencies, the PA is suspect or the input to the PA is reduced. Check the
are Low
circuitry of the PA (Q106) and the PA driver (Q103):
1.
2.
3.
4.
T able 10.4 PA bias currents in mA at different power levels
.
Frequency
band
B1
H5
H6
TP9100 Service Manual
© Tait Electronics Limited May 2005
Remove the can and
PA BOT
Check that the PA output matching capacitor are in the correct
position as depicted in the latest BOM revision.
Go to Task 21 – the PIN switch and LPF require checking.
Enter the CCTM command 331 to check the DAC value of final
). Record the value x returned.
bias 1 (
CDC TX FIN RXAGC
Enter CCTM command 114 0 to turn off power control. Note the
current reading on the DC power supply. This is the bias current.
Table 10.4 shows the bias currents for each power setting.
Enter the CCTM command 32 to place the radio in receive mode.
If the current measured in
Driver and PA" on page
Very low
power
200 200
150 800
200 800
can.
PA LPF BOT
Step 2 is correct, go to
230. If not, go to Task 11.
Low Mid
power power
200
800
800
Transmitter Fault Finding
"Biasing of PA
High
power
200
800
900
229