TB 9-4920-460-24
b. Adjustments
(1) Adjust TCXO U-25/R90 (fig. 2) for a frequency counter indication of
108.10 MHz 150 Hz.
(2) Repeat paragraph a (3) and (4) above.
(3) Turn TI off.
(4) Set the FUNCTION switch to 29-88.
(5) Press and hold down the MB NAV ID switch while turning the TI on.
(6) When Enter Cal Code appears on TI screen, enter 953 on TI keypad.
CAUTION
Once entering the TI calibration tables do not depress any
buttons unless directed to do so in the procedure. Doing so
may cause loss of the TI memory. Only follow the instructions
outlined in this procedure or the instructions displayed on TI.
(7) The following will appear on the TI display:
1-TxDirect
2-TxRamp
3-RxDirect
4-RxRamp
(8) Press 2 (TxRamp) on TI keypad.
(9) Ensure TI display indicates 29.00 MHz.
(10) Connect measuring receiver to TI ANTENNA connector and configure
measuring receiver for power measurements.
(11) If measuring receiver does not indicate within limits specified in first row of
table 6, adjust TI RF OUTPUT toggle switch to adjust TI to as close to nominal as possible.
NOTE
Use the left and right arrow keys on the keyboard to move
through the TI frequencies.
(12) Repeat technique of (11) above for remaining frequencies listed in table 6.
Table 6. TxRamp COMM DAC Table Adjustment.
Measuring receiver indications
Test instrument
(dBm)
Power output
Min
Max
(MHz)
(dBm)
29
0
-2
+2
35
0
-2
+2
45
0
-2
+2
55
0
-2
+2
65
0
-2
+2
75
0
-2
+2
85
0
-2
+2
88
0
-2
+2
14