AR 10046836, Operating And Service Manual

Page: 27 / 62

Rev A 7
2. OPERATING INSTRUCTIONS
2.1 GENERAL
Operation of the Model 500W1000C broadband amplifier is quite simple. The amplifier’s input signal, whether
swept or fixed in frequency, is fed into the jack marked RF INPUT, and the amplifier’s output signal is taken
from the jack labeled RF OUTPUT . The unit is turned on by activating the front panel POWER switch. In
the event of a major malfunction, protection is provided by a circuit breaker located on the unit’s rear panel.
CAUTION:
The Model 500W1000C Amplifier
will provide 100% of rated power
without foldback into a mismatched load. The amplifier will operate
without damage or oscillation with any magnitude and phase of
source and load impedance.
However, placing the amplifier in the
operate mode without a load connected to the output connector is not
recommended. It has also been designed to withstand, without damage,
RF input power levels up to twenty (20) times its rated input of 1mW.
However, signal levels higher than 20mW or transients with high peak
voltages can damage the amplifier. Also, accidental connection of the
Model 500W1000C’s output to its input (either through direct connection
or parasitic feedback paths) will cause oscillations that may permanently
damage the unit’s input transistors
The 500W1000C Amplifier is protected from input overdrive by an automatic level control circuit. The
500W1000C RF power transistors are protected from over temperature by sensing the chassis temperature near
the RF output transistors. In the event of a cooling fan failure or an airflow blockage, the DC voltage will be
removed from the RF stages, when the chassis temperature reaches approximately 70°C.
Normal operation can be resumed after the chassis temperature drops below 70° C.
2.2 CONTROL AND INDICATOR FUNCTIONS
The Model 500W1000C’s front panel is shown in Figure 2-1; the unit’s rear panel features are detailed in
Figure 2-2.
2.2.1 Keylock Switch
The Keylock Switch is provided for protection from unauthorized use or unexpected remote control of the
amplifier. The amplifier can only be turned on locally when the Keylock Switch is in the LOCAL position.
Likewise, the unit can only be turned on or controlled remotely when the Keylock Switch is in the REMOTE
position. Placing the Keylock Switch in the INHIBIT position places the amplifier in the RF Off mode and
prohibits any control of the amplifier.