AR 0053007, Operating And Service Manual

Page: 29 / 86

Rev A 5
2. OPERATING INSTRUCTIONS
2.1 GENERAL
Operation of the Model 2500A225C 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 2500A225C 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 2500A225C’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 2500A225C Amplifier is protected from input overdrive by an automatic level control circuit. The
2500A225C 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.