Radio Performance - Decagon Devices EM50 Operator's Manual

Em50 Series
6.4

Radio Performance

The maximum range of the radio modules in the radio logger and
DataStation are affected by the environment, installation method,
and antenna choice. Maximizing the range of your radio network
requires you to consider these factors.
Buildings, hills, vegetation, vehicles, and other environmental ob-
structions sometimes shorten the radio range, sometimes drastically.
You should ensure a clear, open path between radio devices. Also,
radio frequency, or RF, interference in the environment around the
radio can reduce the usable range (even if not using the same radio
frequencies). You should consider nearby growing vegetation when
designing and testing your radio network. Some radio networks work
fine when the vegetation is sparse, yet may fail when vegetation is
full.
You can increase the effective transmit range by maximizing the
above ground height of the radio antenna. This helps ensure a clear
path for the radio signals and reduces the amount of signal absorbed
by the earth. Use an antenna extension cable to help position your
antenna when it is not practical to install the logger higher off the
ground. If you mount the radio logger to a metal pole, you should
mount the antenna to the top of the metal pole so it is free to radiate
the signal above the pole.
Replacing the stock antenna on your radio device with a high gain
antenna can greatly increase the radio range. Consider using a di-
rectional Yagi antenna or a high-gain omni-directional antenna when
you want to extend the range of your radio network. A high-gain
antenna can also help overcome the effects of unavoidable environ-
mental obstructions.
The ECH2O telemetry system also supports a simple relay for use
with Transmit Mode networks. Combining a relay and high-gain an-
tennas allows radio devices to communicate over very long distances.
Contact Decagon for more information on using a relay in your radio
network.
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