Telonics Precision Direction Finding Antenna Array
RA-NS

Figure 1. RA-NS-RA-2A in vertical polarization

Introduction

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.

Figure 2 Null polarization plot

Key Features

1. 1 degree bearing accuracy is possible using the deep forward null in the pattern.
2. Accuracy is not dependent on the gain of the individual antennas selected.
3. Selecting lower gain antennas and using horizontal polarization minimizes the received signal bounce.
4. The use of the TAC-5 assures repeatable accuracy not possible with "old peak null" technology.
5. The array has been mounted on vehicles for portability as well as permanent installations at fixed sites.
6. The array comes standard with 2 17ft. cable lengths to accommodate mast heights up to 12 feet above ground level or vehicle level.
7. 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
RA-NS-RA-2A Vertical polarization only (can be switched to horizontal polarization by using RA-NS-B bracket sold separately)	2 element "H" type	4 dBd
RA-NS-RA-3	3 element Yagi	6 dBd
RA-NS-RA-4A	5 element Yagi	9 dBd
RA-NS-RA-4B	8 element Yagi	11.8 dBd

* Please specify choice of frequency band:

Technical Note about RA-NS arrays