Codan Radio Communications VT 3A130 F Users manual

User's Guide

The VT-3A130 Transmitter is a synthesized multichannel AM transmitter designed to interface
with the MT-3 Repeater Systems, while still maintaining MT-2 system compatibility. Both MT-3
systems are characterized by dependable low maintenance performance under the most severe
environmental conditions. In addition, all units are burnt-in for 24 hours and are accompanied by
a complete test report.

The VT-3A130 Transmitter operates in the 118 - 137 MHz aviation band. The transmitter’s
frequency stability is controlled by an OST-3A138 AM Enhanced Synthesizer. The Synthesizer
module can be programmed for up to 16 channels. A channel programmer can preprogram the
first 15 channels; channel 16 can be programmed from the front panel and channel 1 can be
programmed by the four BCD switches located on the MT-3 AM Transmitter Main Board.

The VT-3A130 modular transmitter family is compatible with all Daniel’s subrack and base station
enclosures.

Transmitter Features

Compatibility MT-2 Series and MT-3 Series Radio Systems

Frequency Generation Synthesized (internal plug-in module)

Channel Selection

Front Panel Control

Amplifier Enable Active to ground

In 25 kHz increments selected by four BCD switches
Preset capability for 16 channels selectable through external control

One 3 position switch:

- NORM (repeat mode)

- OFF

- KEY TX PTT Activation:

- Active to ground with time-out timer

- Active to ground without time-out timer

- Microphone activated without time-out timer

- Front Panel switch (KEYED) without time-out timer, (NORM) with or
without time-out-timer.

Performance Specifications

Overall Transmitter Specifications

Parameter Specification Reference

Operating Temperature Range -30°C to +60°C

Optional -40°C to +60°C
Optional -50°C to +40°C

Type MT-3 Series Transmitter

Family VT-3A130

Frequency Range 118 - 137 MHz

System Impedance 50 ΩType N

RF Power Output 1.0 – 3.0 Watts adjustable (carrier only) RTCA DO-186A

Paragraph 2.3.1

Emission of Radio Freq. Energy More than 50 dB below carrier RTCA DO-186A

Paragraph 2.3.7(b)

Carrier Noise Level More than 45 dB below carrier RTCA DO-186A

Paragraph 2.3.6

Duty Cycle 100%; Continuous operation from -30°C to +60°C

Optional -40°C or -60°C

Channel Spacing 25 KHz

Emission Identifier 6K00A3E and 5K6A3E Amplitude Modulation

Operating Humidity 95% Relative Humidity (Non-condensing) at +25°C

Operating Voltage +13.8 VDC Nominal +9.5 VDC regulated

Active Current +13.8 VDC supply < 2A @ 25°C, at 3 Watts RF output

<2.5A -40˚C to +60˚C

Channel Selection In 25 kHz increments selected by four BCD switches.

Preset capability for 16 channels selectable through
external control.

Frequency Stability Standard: ±1 ppm -40°C to +60°C

± 2 ppm, -50°C to -40°C

FCC Type Approval H4JVT-3A130-F

Industry Canada Certification 142A-VT3A130F

PTT Time-Out-Timer Selectable 1 seconds to 8 hours.(factory set 5 min)

Standby Current (9.5 VDC)
and Rise time

Refer to Transmitter Standby Modes in Theory of
Operation

RTCA DO-186A
Paragraph 2.3.11