TB 9-6625-2278-24
(17) Press POWER REF OSC switch to on position (LED on). Record ultimeter
indication as V1.
(18) Disconnect multimeter negative lead from power meter VRF (fig. 4) and connect
multimeter negative lead to power meter chassis ground. Record ultimeter indication as
VCOMP.
(19) Calculate the POWER REF OSC output level PRF from the below listed
formula:
2 VCOMP (V1 -V0) +V02 -V12
PRF
Where:
PRF = power reference oscillator output power level
VCOMP = value recorded in (18) above
V1 = value recorded in (17) above
V0 = value recorded in (16) above
R = value recorded in (4) above
Calibration factor = value for thermistor mount at 50 MHz
(20) If calculated PRF is not between 0.988 and 1.012 mW, perform b below.
b. Adjustments. Remove TI top cover and set POWER REF OSC switch to on
position (LED on) and adjust LEVEL ADJUST G1A1R4 so that calculated PRF in (19)
above is between 0.993 and 1.007 mW (R).
NOTE
Do not perform power supply check if all other parameters are
within tolerance.
a. Performance Check
(1) Press TI LINE switch to OFF position and remove TI top and bottom covers.
(2) Loosen screws that secure A3 CPU assembly.
(3) Press LINE switch to ON position and allow TI to warm-up for 30 minutes
before proceeding to (4) below.
(4) Connect multimeter negative lead to chassis ground and then connect
multimeter positive lead to A9TP8 (fig. 5). Multimeter will indicate between 14.25 and
15.75 V dc. Record multimeter indication.