MX Series - 1 Watt UHF AMPLIFIER
TSM 20-312 rev 0: June 14, 2000
8
1
W UHF Amplifier
GENERAL DESCRIPTION
INTRODUCTION
This manual describes the LARCAN 1Watt UHF amplifier which is designed to operate on channels 14
through 69. This solid state 1W UHF amplifier was designed to operate conservatively at 1W peak sync
visual RF power, and 0.1W average aural carrier RF power, with superb performance, reliability and
operating economy. This amplifier accepts an on-channel internally diplexed (in a 10:1 ratio Vis to Aur)
composite driving signal of about 1mW peak visual RF as input to its RF chain.
The 1W amplifier and channel processor chassis’ are designed to fit in a single 19" customer-provided
cabinet rack, and require 5.25" (3RU) of vertical panel space for a complete transmitter or translator
system. Alternatively, a 19" customer-provided tabletop cabinet could be substituted if the site requires it.
The RF amplifier and other sub-assemblies are all convection cooled. The simplicity of design, the
deployment of all modular and other subassemblies, and the use of standard readily available
components, also enhances serviceability.
Peak forward and reflected power are displayed on an analog percent power meter located on the front
panel of the amplifier unit.
AMPLIFIER CHAIN
The amplifier chain consists of two stages of amplification. These are the Pre-amplifier and PA stages.
Both stages operate in class A. The system has a minimum gain of 30dB.
The internally diplexed composite RF output of the channel processor or exciter is fed to a conservatively
designed broadband solid-state Pre-amplifier. This amplifier requires no tuning or adjustment. Simplicity of
operation, reduced maintenance costs and increased reliability are a few of the major benefits derived
from this module.
This first stage is a broadband pre-amplifier module which delivers about 40mW to the PA stage to
achieved overall 1W sync peak at the output. The gain of the pre-amplifier is about 18 dB.
The 1W PA module also operates in class A mode, and has a gain of about 15dB. This amplifier is also
wideband and does not require retuning even if it has to operate on another channel.
TRANSMITTER CONTROL
Because of its simple and rugged design, this amplifier does not require any special control, interlocking,
nor protection circuitry. The amplifier can operate safely over ambient temperature of over 45
°
C, and will
tolerate extremely high VSWR.
The control is simply a front panel switch which applies 117VAC to the power supply.
