Codan Radio Communications VT-3A130-F 25kHz AM TRANSMITTER User Manual 1

Codan Radio Communications 25kHz AM TRANSMITTER 1

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 In 25 kHz increments selected by four BCD switches
Preset capability for 16 channels selectable through external control
Front Panel 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.
Amplifier Enable Active to ground
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 Type 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
RTCA DO-186A
Paragraph 2.3.11
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
Audio Specifications
Parameter Specification Reference
Audio Input -30 to 0 dBm into a 600 balanced load
Audio Frequency Response Flat audio; +1/-5 dB: 350 Hz - 2.5 kHz RTCA DO-186A
Paragraph 2.3.5.1
Audio Frequency Distortion
1 kHz tone, 50kHz Low Pass Filter
Less than 5%+25˚C at 85% modulation
Less than 10% -40˚C to +60˚C at 85% modulation
Less than 15% >+40˚C to +60˚C
RTCA DO-186A
Paragraph 2.3.4
Synthesizer Specifications
RF Power Output: +3 dBm Nominal
Physical Specifications
Physical Dimensions: Width:
7.1 cm (2.8 in)
Height:
12.8 cm (5.05 in)
Depth:
19 cm (7.5 in)
Module Weight: 1.4 kg (3.0 lb.)
Corrosion Prevention:
Anodized aluminum construction. Stainless steel hardware. Selectively conformal
coated glass epoxy 2 and 4 layer printed circuit boards. Gold plated module
connectors.
Module Design:
Compact Eurostandard modular design. Plug-in modules mate with Daniels
standard MT-3 repeater subrack. Subracks and modules comply with IEEE 1101,
DIN 41494 and IEC 297-3 (mechanical size / modular arrangement).
External Connections:
RF Connection: Type N connector located on the transmitter module front panel.
Motherboard Connections (Audio, Power, and Control) are made through a 48 pin,
gold plated, type F connector on the rear of the transmitter module. User
connection is made through a mated “mother board” assembly of the repeater
subrack. Type F standard connector complies with DIN 41612 Level 2 (200 mating
cycles, 4 day 10 ppm SO2 gas test with no functional impairment and no change
in contact resistance).
Frequency Select Handle
Performance Specifications
Temperature Range: -30°C to +60°C.(Optional -40°C to +60°C)
Supply Voltage: +9.5 VDC
Supply Current: Less than 35 mA operate; less than 4.0 mA standby mode

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