Broadcast Electronics Marti Electronics ME-40, Manual

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54
©2011 Broadcast Electronics
INPUT
OUTPUT
DIRECTIONAL COUPLER OUTPUT:
FORWARD
REFLECTED
0.0 dBm at 50 Ohms
3 to 50 Watts RF at 50 Ohms (adjustable)
2.2V DC at 50 Watts RF Output
Less than 1V DC at 50 Watts RF Output at 50
Ohms
5.12.1 REMOVAL AND INSTALLATION – RF Amplifier
REQUIRED EQUIPMENT. A number 2 Phillips screwdriver with a 4 inch (10.16 cm) blade is
required to remove the RF amplifier assembly from the exciter chassis
Procedure to remove the RF amplifier assembly requires the exciter be placed on a suitable work
surface. To remove the RF amplifier assembly, proceed as follows:
WARNING
DISCONNECT PRIMARY POWER TO THE EXCITER BEFORE PROCEEDING.
WARNING
a. Disconnect the primary power from the exciter
b. Remove the exciter top-cover and disconnect J15 from PI5 of the RF amplifier
power/control cable.
c. Disconnect BNC connector P18 from J18 on the rear of the RF amplifier assembly.
d. Disconnect BNC connector P17 from J17 on the front of the RF amplifier assembly.
e. Remove the six screws from the underside which secure the assembly to the chassis.
f. Remove the RF amplifier assembly from the exciter chassis.
To install the RF amplifier assembly after repairs have been completed, follow the REMOVAL
PROCEDURE in reverse order.
5.12.2 DETAILED THEORY OF OPERATION – RF Amplifier
The RF amplifier assembly consists of: 1) two series-pass voltage regulator transistors, 2) a +20V
regulator circuit, 3) a temperature sensing circuit, and 4) an RF amplifier circuit board. All wiring