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 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  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 600Ω 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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