User Manual
Table Of Contents
- 1GENERAL
- 1.1Introduction
- 1.2Performance Specification
- 2THEORY OF OPERATION
- 2.1Amplifier Operation
- 2.2Power Requirements
- 2.3RF Circuitry
- 2.3.1UT-3/400 Lowpass Filter
- 2.4Power Control Circuitry
- 2.5Power Sensing Circuitry
- 2.5.1Output Power Sense
- 2.5.2VSWR Sense
- 2.5.3VSWR Overload
- 3UT-3/400 AMPLIFIER ALIGNMENT
- 3.1General
- 3.2Repair Note
- 3.3Recommended Test Equipment List
- 3.4Printed Circuitboard Numbering Convention
- 3.5Standard Factory Settings and Jumper Configuration
- 3.6UT-3/400 AmplifierAlignment
- 3.6.1General
- 3.6.2UT-3/400 Amplifier Adjustment
- 3.6.2.1General Set-Up
- 3.6.2.2Output Power Alarm (Forward Power)
- 3.6.2.3Output Power
- 3.6.2.4Antenna VSWR Alarm (Reverse Power)
- 3.6.2.5Antenna VSWR Overload
- 3.6.2.6Procedure Verification
- 4ILLUSTRATIONS AND SCHEMATIC DIAGRAMS
- 4.1UT-3/400 UHF Amplifier Component Layout
- 4.2UT-3/400 UHF Amplifier Schematic Diagram
- 4.3UT-3/400 UHF Lowpass Filter Component Layout
- 4.4UT-3/400 UHF Lowpass Filter Schematic Diagram
- 5PARTS LISTS
- 5.1UT-3 / UT4 UHF Amplifier Electrical Parts List
- 5.2UT-3/400 UHF Amplifier Mechanical Parts List
- 5.3UT-3/400 UHF Low Pass Filter Electrical Parts List
- 6REVISION HISTORY

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.