AR 10036390, Operating And Service Manual

Page: 23 / 56

Rev D 7
2. OPERATING INSTRUCTIONS
2.1 GENERAL
Operation of the Model 800A3B 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 800A3B Amplifier is typically not critical in regard to source
and load Voltage Standing Wave Ratio (VSWR) and will remain
unconditionally stable with any magnitude and phase of source and load
VSWR. 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 800A3B’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.
2.2 CONTROL AND INDICATOR FUNCTIONS
The Model 800A3B’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 off mode and
disconnects primary AC power from all circuits except for the CPU and control circuits.
2.2.2 POWER Switch
The momentary POWER switch turns the main power to the amplifier on and off. The status of the green
light-emitting diode (LED) in the switch indicates whether the amplifier’s power is on or off. The main fans
are active when power is on. The graphic display is active as long as the main power circuit breaker CB1 on
the rear panel is on.