ImmersionRC | ImmersionRC RF Power Meter
5
Examples of Use
Example 1: Comparing Antennas
This example is relatively simple, two antennas (possibly equivalent antennas from two different
vendors) are available, and are to be compared.
For this particular example, 5.8GHz omni-directional whips are to be compared.
First, setup the transmitter, on a tripod, ideally in an open area without much RF pollution, with few
reflective surfaces. A 25mW 5.8GHz transmitter works fine for this. Attach a ‘known good’ 5.8GHz
antenna onto the Tx, and power it up.
Setup the power meter for 5800MHz, Average mode (not Peak), and attenuator setting at 0dB.
Screw the first of the whips to be compared onto it, vertically (same polarization as the transmitter) and
place it on another tripod.
Adjust the distance between tripods until the power meter reads approx. -25dBm (the mid-point of the
range of the device).
When the meter is around -25dBm (anywhere from -20 thru -30 will be just fine), make a note of the
precise reading, and switch the antenna on the power meter for the second (or subsequent) to be
compared with.
For each antenna to be compared, make a note of the readings. Note that a higher reading (= less
negative) means a higher RF power received.
For example:
Antenna 1: -25dBm
Antenna 2: -27dBm
Antenna 3: -23dBm
For this example, Antenna 3 is showing 4dB greater received power than antenna 2.
