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5.12.3 MAINTENANCE
Although the following controls are not located on the RF amplifier assembly, the controls effect
the operation of the RF amplifier. The adjustment procedure for each control is presented in the
power supply/control circuit board section of this manual.
• TEMP TRIP (R27)
•
TEMP CAL (R25)
•
FWD CAL (RS)
• RFL CAL (R9)
REQUIRED EQUIPMENT. The following tools and equipment are required for electrical adjustment
procedures: Insulated adjustment tool, shipped with the exciter (P/N 407-0038), Non-inductive,
100 watt, 50 Ohm test load, adapter, BNC jack to type N plug for test load (P/N 417-3288),
adapter, type N jack-to-jack for test load (P/N 417-3841). coaxial accessory cable, BNC connectors,
shipped with exciter (P/N 947-0020).
5.12.3.1
RFL NULL (R12). The RFL NULL control on the RF amplifier circuit board adjusts the
directivity of the reflected power directional coupler. Potentiometer R12 is adjusted as
follows.
Procedure to adjust reflected power null control R12; proceed as follows:
WARNING
DISCONNECT THE PRIMARY POWER TO THE EXCITER BEFORE PROCEDING.
WARNING
a. Disconnect the exciter primary power.
b. Remove the exciter top-cover and the access hole plug at the top and rear of the RF
amplifier assembly (refer to Figure 5-11).
c. Connect a l00 watt non-inductive test load to the exciter rear-panel RF OUTPUT
receptacle.
d. Apply primary power and operate the exciter for 50 watts as indicated on the front panel
meter.
e. Depress the front-panel RFL meter function switch.