User's Guide

DE
DANIELS
ELECTRONICS
UHF Amplifier Instruction Manual UT-3 406 - 512 MHz 1-1
1 GENERAL
1.1 Introduction
The UT-3/400 Amplifier provides the final stage of RF amplification and filtering for the entire
UHF Transmitter UT-3 406 -512 MHz family. The amplifier has four distinct frequency ranges:
406 to 430 MHz, 450 to 470 MHz, 470 to 490 MHz and 490 to 512 MHz as well as two distinct
output power ranges: 0.5 to 2.0 Watts and 2.0 to 8.0 Watts. The UT-3/400 Amplifier is housed in
a machined aluminum case that ensures optimum RF shielding, provides a good ground, and also
acts as a heatsink.
Additionally, the UT-3/400 Amplifier is equipped with output power and VSWR sensing lines
which can be individually configured as open collector or linear outputs. The internal VSWR
sensor protects the amplifier from high antenna VSWR by approximately halving the amplifier's
RF gain when a VSWR overload condition is present.
Output filtering for the UT-3/400 Amplifier is provided by the UT-3/400 Lowpass Filter Board.
The lowpass filter assembly is mounted in a separate compartment of the amplifier case in order to
provided maximum attenuation of harmonic and other spurious signals.
Refer to Section 4 for the UT-3 406 - 512 MHz UHF amplifier and lowpass filter component
layouts and schematic diagrams
1.2 Performance Specification
Type: MT-3 series UHF Amplifier module.
Compatibility: MT-3 series Transmitter Main Board.
Frequency Range: 406 to 430 MHz, 450 to 470 MHz, 470 to 490 MHz or
490 to 512 MHz.
RF Power Output: adjustable 0.5 to 2.0 Watts or 2.0 to 8.0 Watts
RF power Input: nominal level adjustable from +4 dBm to +10 dBm,
held within +/- 2 dB of nominal.
Ouput Impedance and VSWR: 50 Ω, Type N connector; 3:1 max. VSWR.
Input /Output Isolation: > 60 dB
Duty Cycle: 100%: Continuous operation from -40˚ C to +60˚C.