Understanding The Dual Scale; Reading Power Measurements To Determine Bearing And Direction - ACR Electronics VECTA 2 - REV A2 Product Support Manual

Once the tone is heard and the rescuer is heading in the direction of the BEACON, the LEDs can
be expected to climb up the Signal Strength Meter visually showing that the BEACON is nearer.
The Audio tone will remain constant.
4.0

UNDERSTANDING THE DUAL SCALE

In most situations a searcher will focus on the COARSE scale to determine signal strength when
scanning the horizon (360°). In some situations a searcher will have two signals 180° opposite that
seem to be the same signal strength. Choosing the right direction oftentimes depends on very
small changes to the FINE scale. It is important to understand the relationship of the COARSE
scale to the FINE scale.
The further from the BEACON transmitter, the weaker the signal; the closer, the stronger the
signal. The Vecta
2
displayed on two columns (16 x 16 = 256).
The COARSE and FINE scales are labeled 1-16. Each COARSE LED step represents a value
increase of 16 units which are represented in the FINE scale. As the Signal level increase the
scales climb up towards the top. When the FINE scale reaches 16 the COARSE scale will
increment up 1 unit.
4.1

Reading Power Measurements to Determine Bearing and Direction

The Vecta is designed to indicate the signal strength of a transmitting BEACON. With the
2
antennas deployed and held in its operating position the Vecta
strength of the received signal and when pointing in the direction of the BEACON the Vecta
display the highest power reading level (You need to determine this in your 360 degree sweep).
Figure 7
When determining bearing you should be focused on the fine scale and looking for the highest
power reading and from slowly scanning left and right you should see where the power starts to
drop off from the highest power reading and proceed forward in that highest readings direction.
Walking or not holding the Vecta
the power meter, ensure you are always in the operating position when recording power
measurements.
Signal Strength Meters measure the decibel level of a signal in 256 units
A COARSE scale reading of 2 combined with a FINE
scale reading of 10 equals an overall signal strength
value of 2.10.
Adding 7 FINE steps to the above signal strength forces
the next COARSE LED to illuminate and the FINE to
loop to 1 again, giving an overall signal strength value of
3.1.
in its operation position can be misleading when trying to read
2
will be able to measure the signal
2
7
will
2
Figure 8
Y1-03-0227 Rev. A2