User's Manual

MARK-IV BROADBAND AMPLIFIERS
User’s Manual
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REV3 01/25/06
Section C. THEORY OF OPERATION
The MARK-IV BROADBAND AMPLIFIERS are self contained modules having the RF Input
and Output ports via SMA-type coaxial connectors and DC plus Control signals via D-
Subminiature 9-pin connector.
These amplifiers modules must be installed on appropriate heat-sinks to dissipate the
heat they generate during normal operation (with or without input signal). It is
recommendable the Case Temperature not to exceed 50 degrees Celsius to benefit the
amplifier’s life span.
The RF Input signal is amplified by the amplifier’s gain and delivered at the RF Output
without changes in frequency, modulation or occupied bandwidth.
Pout = Pin + Gain
The MARK-IV BROADBAND AMPLIFIERS are equipped with Automatic Level Control (ALC)
circuitry to limit the output power to the factory preset level, preventing that an input
drive signal level plus the amplifier’s gain would exceed the maximum authorized output
power level. In that case, the ALC circuit will proportionally decrease the gain as
required not to exceed the preset output level. A red LED on the side of the amplifier’s
case is lit when the ALC circuit is in operation.
The amplifiers are also equipped with Input Overdrive Protection (passive “fuse-type”) to
prevent further damage of its internal stages in case of accidental very strong signals
well above the maximum input level required for normal operation.
The MARK-IV BROADBAND AMPLIFIERS requires an external DC Power Supply, typical +28
VDC. They can operate at +24 VDC with approximately 1 dB reduction on gain and
linearity performance. The current draw is less than 4 Amps at maximum output power.