TB 9-6625-2297-35
(10) Set power meter RANGE switch to COURSE ZERO and adjust power meter
front panel COURSE ZERO control for a zero meter indication.
(11) Fine zero the power meter on the most sensitive range and then set the power
meter RANGE switch to 1 mW.
(12) Set multimeter to measure dc microvolts and ensure inputs are disconnected
from chassis ground.
(13) Connect multimeter Input HI to center conductor of power meter rear panel
VCOMP connector and Input LO to center conductor of power meter rear panel VRF
connector.
(14) If multimeter indication is between 400 and +400 V, record multimeter
indication and proceed to (16) below; if not, proceed to (15) below.
(15) Hold power meter FINE ZERO control and adjust COURSE ZERO control for
a multimeter indication between 200 and +200 V. Record multimeter indication.
(16) Round off indication recorded in (14) or (15) above to the nearest microvolt and
record this value as V0.
(17) Press FUNCTION SHIFT key then DATA ENTRY PWR REF/⇒ key. Record
multimeter indication as V1.
chassis ground.
(19) Record multimeter indication as VCOMP.
(20) Calculate the power reference oscillator output level using formula below. If
calculated power reference oscillator output level is not between 0.988 and 1.012 mW,
perform b below.
2 VCOMP (V1-V0) +V02-V12
PRF =
_______________________
4 R (Calibration Factor)
WHERE:
PRF = Power reference oscillator output level
V0 = Value recorded in (16) above
V1 = Value recorded in (17) above
VCOMP = Value recorded in (19) above
R = Value recorded in (5) above
b. Adjustments
(1) Adjust R114 (fig. 1) slightly and repeat 11a above until calculated power
reference oscillator output level is between 0.988 and 1.012 mW (R).
9
