User's Manual

Table Of Contents

MReX Transceiver User Manual v1.92 Firmware

Antenna

It is common in radio systems to consider an omni or directional antenna. Both have their advant-

ages and disadvantages as follows.

If in doubt, consult a local aerial specialist who will be able to advise and construct an aerial best

suited to your application.

Omni antenna

Omni antenna have the advantage of transmitting and receiving signals equally well in all horizontal

directions. This means that if the transmitter or the receiver moves, the antenna will not need to be

changed/adjusted to compensate.

This is the common antenna used in cellular phones and handhelds radios.

Directional antenna

Directional antenna have the ability to focus energy in a particular direction. This advantage in-

creasing the maximum distance between transmitter and receiver units. Since the signals are fo-

cused/concentrated into a direction it also increase the overall performance of the system.

This is mainly used for fixed transmitter and receiver locations.

Antenna Elevation

As with any radio receiver, raising the height of either the transmitter or receiver antenna will result

in dramatic improvements to the maximum possible receive distance. Although a high power trans-

mission will increase distance, the installed height of the receiver antenna is the key to a high per-

forming system.

When close to the ground the major obstacle to overcome, since radio signals are mainly “line of

sight”, is the curvature of the earth. The typical distance to expect can be approximately calculated

as follows:

√

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