DVOR Navigation Aid Print E-mail
Benefits | Specifications | Download a pdf of this product (136k)

DVOR ImagesInstalled at airports and en-route locations, the Doppler VOR Ground Beacon from Interscan is one of the primary navigational aids for a nation's airways system. It is a ground based, radio navigation aid, transmitting an omni-directional signal that enables an aircraft to determine its bearing relative to the location of the beacon.

Designed to exceed all ICAO requirements, it is the ideal complement to the LDB-102 DME, which has also been developed and manufactured by Interscan.

The VRB-52D DVOR Beacon comprises:

  • an equipment rack, containing all the electronics required to generate the DVOR signals, together with a power supply/battery charger;
  • an antenna distributor, to sequentially switch the signals from the rack around the ring of sideband antennas;
  • an antenna system, comprising a ring of 48 sideband antennas and a central carrier antenna, mounted on a suitable ground plane.

Benefits of the VRB-52D include:

High reliability
  • requires no cooling fans
  • meets or exceeds all ICAO requirements
  • high grade components and coated printed wiring boards
Can be used in difficult terrain
  • suited for elevated counterpoise or ground mounted systems
  • greatly improved VOR service from difficult sites
Proven performance
  • over 500 navaid installations worldwide
  • Interscan has developed capability in the installation and commissioning of navaid equipment in rugged and inhospitable locations
Low maintenance costs
  • built-in test facilities
  • Remote Maintenance Monitoring (RMM) available
Designed to meet diverse requirements
  • 50 watts (standard) or optional 100 watts transmitter
  • single or dual beacon: two identical equipment racks used in dual configuration
  • optional float battery for true "no break" power sources

Specification Summary

The following characteristics apply over the range of environmental conditions specified.

R.F. Signal Output
Output power   50 Watts or 100 Watts
Frequency Band   108MHz to 118MHz
Carrier frequency stability   0.002%
Antenna system   Alford loop antennas
1 carrier, 48 sideband
Polarisation   Horizontal
Bearing accuracy
(for all elevation angles
from zero to 40 degrees)
  Typically 0.5 maximum error
Bearing stability
  Typically less than 0.1
Reference Phase Modulation (AM)
Frequency   30Hz 0.01%
Depth of modulation   28% to 32%
Variable Phase Modulation (FM on sub-carrier)
Sub-carrier frequency   9960Hz+/-0.2%
Mean modulation depth
by sub-carrier
Frequency of modulation   30Hz 0.01%
Deviation ratio   161
Sub-carrier Modulation
AM on sub-carrier
(Measured at least 300m (1,000ft) from central antenna)
  Less than 40%
Modulation tone   1020Hz 50Hz
Modulation depth   0-15% adjustable (nominal 10%)
Code   International Morse
up to five letters
Keying speed   7 words per minute (adjustable)
Repetition rate   6 times per minute (adjustable)
DME keying   interfacing provided
for co-located DME

Voice Modulation
Frequency Range   300Hz to 3000Hz
Modulation depth   0 to 30% adjustable
(nominal 10%)
Noise due to signal communications   Negligible
Monitoring Alarm Limits
Bearing information   Adjustable to 1.0 in 0.1 steps
30Hz AM modulation depth   15% below nominal, adjustable
30Hz FM modulation depth   15% below nominal, adjustable
Sub-carrier modulation depth   15% below nominal, adjustable (30Hz AM, 30Hz FM and Sub-carrier may also be optionally set to alarm at 15% above nominal level)
Code failure   Continuous or absent Tone
Failure of antennas   Alarm for failure of two diametrically opposite antennas. Optional internal monitor for detection of single antenna failure.
Failure of monitor   Self-check on bearing monitor
Input Power, single DVOR
Primary Supply   200 to 260V AC, 50/60Hz
600VA (50W rack)
900VA (100W rack)
Standby Supply   22V to 28V DC
16A (50W rack)
22A (100W rack)
Input Power, dual DVOR   The above consumption is required for each rack
Indoor equipment    
Temperature   -10C to +60C
Humidity   95% (to 45C)
50% (45C to 60C)
Outdoor equipment    
Temperature   -40C to +70C
Humidity   100%
Wind speed   160 km/h (100mph)

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