Benefits | Specifications | Download a pdf of this product (124k) 
 The Interscan LDB-102 distance measuring equipment (DME) is a ground based navigational aid for use by aircraft. Signals transmitted between an aircraft and a DME ground beacon enable the aircraft to accurately determine its distance from the beacon. The DME is used at an airport or en-route, and is one of the primary navigation aids in an airways system.
A DME system comprises a ground beacon - the transponder - and an airborne transmitter/receiver - the interrogator. In operation the interrogator transmits to the transponder which then replies to the interrogator. The time difference between the signals, measured at the interrogator, is directly dependent upon the distance between the aircraft and the beacon.
Up to 100 aircraft may use the system simultaneously. The beacon has an operational range of approximately 370 kilometres (200 nautical miles), but this depends on aircraft height, ground obstructions and other factors.
Benefits of the LDB-102 include:High reliability
- hardware based design
- contains no moving parts
- fully solid state, including transmitter 1 kW power amplifier
- meets or exceeds all ICAO requirements
- can withstand major power supply fluctuations and spikes
Options
- Low power version for use with ILS or terminal approach applications
- Directional antennas, and high wind rating antenna available as option
Large Installed Base
- proven capability in the installation and commissioning of navaid equipment in rugged and remote locations
- Interscan has over 500 navaid installations throughout the world
Meets a range of requirements
- 1 kW (standard) or 150 Watt (optional) output
- single of dual beacon
- includes AC power supply/battery charger, allowing use of float battery for “no break” power source
Specification Summary
The following characteristics apply over the range of environmental conditions specified.
| Transmitter |
|
|
| Operating frequency |
|
962MHz to 1213MHz |
| Frequency accuracy |
|
0.002% |
| Peak output power |
|
1 kW (150 watt optional) |
| Spectrum |
|
DME/N, per ICAO Annex 10 |
| Transmission rate |
|
2800 pp/s maximum |
| |
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|
| Receiver |
|
|
| Operating frequency |
|
1025MHz to 1150MHz |
| Frequency stability |
|
0.002% |
| Sensitivity (70% reply) |
|
91dBm (at cabinet connector) |
| Adjacent channel rejection |
|
80dB min |
| IF Rejection |
|
80dB min |
| Echo suppression |
|
Long and short distance |
| CW protection |
|
Replies to signals
10dB above CW level |
| |
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|
| System |
|
|
| Transponder capacity |
|
252 (X and Y) |
| Reply delay |
|
100 interrogators
35 to 50 µsec adjustable, X-channels
50 to 56 µsec adjustable, Y-channels |
| |
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| Monitoring alarm limits |
|
|
| Reply Delay |
|
Adjustable to ± 1 µsec, in 0.1 µsec steps |
| Pulse spacing |
|
Adjustable to ± 1 µsec, in 0.1 µsec steps |
| Reply efficiency |
|
60% |
| Power |
|
Adjustable from -1 to -6 dB decrease |
| Transmitter pulse rate |
|
833 pp/s |
| Identification |
|
Absence of 40 to 120 seconds, adjustable |
| Pulse width |
|
±0.5 µsec, adjustable |
| Pulse rise & fall times |
|
Exceed 3.5 µsec, adjustable |
| |
|
|
| Antenna (omni-directional type) |
| Polarisation |
|
Vertical |
| Gain (mean) |
|
8dBi |
| VSWR |
|
2:1 maximum |
| Pattern circularity |
|
± 0.5 dB |
| |
|
|
| Input Power (Single or Dual) |
| Primary supply |
|
200 to 260 V AC, 50/60Hz 350VA |
| Standby Power |
|
21 V to 28V DC (24V DC nominal) |
| Current |
|
12A maximum (1kW DME, max traffic) |
| |
|
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| Environmental |
|
|
| Indoor equipment: |
|
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| Temperature |
|
-10°C to +60°C |
| Humidity |
|
95% (to 45°C); 50% (45°C to 60°C) |
| Antenna: |
|
|
| Temperature |
|
-40°C to +70°C |
| Humidity |
|
100% |
|
|
