4
BARRETT 4075 LINEAR AMPLIFIER - OPERATING & INSTALLATION MANUAL
Introduction
The Barrett 4075 is a solid-state linear amplifier operating from 1.6 MHz to
30 MHz. It can be supplied with a power output level of either 500 watts or
1000 watts.
Extensive self-test, system monitoring, and protection circuits are provided,
with status and tuning information being displayed on a large OLED display.
The exciter for the 4075 linear amplifier is a Barrett 4050 Transceiver set
to “4075 Linear Amplifier” as the antenna type, where its power output is
reduced to a maximum of 30 W, and 40 W above 20 MHz. The ALC voltage
for the exciter is derived at the Linear Amplifier’s output, and is passed to the
exciter via the Breakout Box.
The Barrett 4075 Power Supply Unit provides the +48 volts required to power
the amplifier.
Terms and Abbreviations
Term / Abbreviation Definition
BoB
Breakout Box
CW
Continuous Wave (used for Morse code)
dB
Decibels
dBc
Decibels relative to the carrier - is the power ratio of a
signal to a carrier signal, expressed in decibels.
dBm
Power ratio in decibels (dB) of the measured power
referenced to one milliwatt (mW).
LPF
Low Pass Filter
OLED
Organic Light Emitting Diode
PEP
Peak Envelope Power
PTT
Press-To-Talk button
Selcall
Selective Calls
SSB
Single Sideband (a transmission format)
USB
Universal Serial Bus
VSWR
Voltage Standing Wave Ration
