Precision Direction Finding Antenna Array (RA-NS)
The RA-NS Precision Direction Finding Antenna series is designed for maximum accuracy and repeatability in direction finding with minimum field maintenance. The RA-NS series employs two beam antenna arrays, critically separated by a lightweight metal cross boom (model RA-CB). The received signals from both antennas are combined precisely out of phase, producing a pattern as shown in Figure 2. The deep forward looking null (-10 to -30 dBV) in the center is bound on either side (+ or - 15 to 30 degrees), by a point of maximum gain (peaks). When this system is combined with a compass rose assembly and Receiver capable of measuring signal strength (TR-5), a repeatable accuracy of ± 0.5 to 2.0 degrees can be attained when working with animals in conditions of relative inactivity and line of sight (LOS) conditions exist.
- 1 degree bearing accuracy is possible using the deep forward null in the pattern.
- Accuracy is not dependent on the gain of the individual antennas selected.
- Selecting lower gain antennas and using horizontal polarization minimizes the received signal bounce.
- The use of the TAC-5 assures repeatable accuracy not possible with "old peak null" technology.
- The array has been mounted on vehicles for portability as well as permanent installations at fixed sites.
- The array comes standard with 2 17ft. cable lengths to accommodate mast heights up to 12 feet above ground level or vehicle level.
- Alternative cable lengths are available by special order for an additional charge
|Model||Name / Description
of Antenna in Array
|Antenna Gain||Fixed Site||Land Vehicles||Boats and Ships|
Vertical polarization only
(can be switched to horizontal polarization by using RA-NS-B bracket sold separately)
|2 element "H" type|
|Each RA-NS array includes:|
|2 ea.||Antennas (see choices below)|
|1 ea.||RA-CB cross boom|
|1 ea.||RA-TC "Tee" clamp (connects boom to mast)|
|1 ea.||TAC-5 Precision two port combiner|
|2 ea.||RW-3-17 cables
(17 foot length accommodates mast heights up to 12 feet above ground level.)
|1 ea.||RW-2 cable (connects Combiner to Receiver)|
|1 ea.||Set of drawings for mast base, compass rose assembly, antenna mounting and cable dress|
|Please Specify Choice of Antenna:|
|RA-3 - (*)|
* Please specify choice of frequency band:
|148.000 - 149.999 MHz||150.000 - 151.999 MHz||159.000 - 160.999 MHz|
|164.000 - 165.999 MHz||172.000 - 173.999 MHz|
|Optional Equipment for RA-NS Arrays|
|RA-NS-B Bracket for switching a RA-NS-RA-2A from vertical to horizontal polarization|
|RW-3-25-BNC 25 ft cable accommodates mast heights up to 20 feet above ground|
|User Must Provide:|
|1 ea.||1.25 - 1.7 inch O.D. Mast, 17 feet long|
|1 ea.||Mast Base with Thrust Bearing and Compass Rose Assembly|