The SHoW DMX Wireless Data System
User’s Manual
Rev 1.4 11-17-08
44 of 48 Pages
High Power and Directional Antennas
The SHoW DMX System includes four different directional high powered antennas,
which are listed in Appendix B. These antennas are approved for use in North America
with CTI # 5600 Transmitters and CTI # 5610 Receivers, and with CTI # 5607 OEM
Transmitters and CTI # 5605 OEM Receivers, and in most cases aren’t approved for use
with the 5601, 5611, 5606 or 5608 International units, as they are too powerful for the
limits placed on 2.4Ghz broadcast equipment by the European (CE) rules
6
These directional antennas provide additional broadcast power to the Transmitters,
increase received signal strength in the Receivers, and improve reception and data
fidelity in the System in a number of ways.
First, these antennas all add more gain that the standard 5dBi omni-directional antennas
will, increasing signal strength. Adding gain will generally increase range and will
improve fidelity in some circumstances.
Second, these antennas are directional, so they focus the available radio energy in a
smaller area the omni-directional antennas do. In other words, these directional
antennas have a limited beam width, much like different theatre lighting instruments do,
so they can be
aimed,
and used to send more of the radio energy in a desired direction.
With directional antennas, you can direct the radio energy where you want it to go, and
limit the amount of energy that goes where you don’t want it to go.
This means that you
may be able to use directional antennas to reduce interference received by your SHoW
DMX system, and also further reduce interference caused in other equipment by your
SHoW DMX System.
Directional antennas tend to produce less reflected or
multipath
radio energy, so they
can be used in highly reflective environments to reduce multipath interference and
improve fidelity.
The more directional the antenna is, the more it will do to enhance range and limit
multipath reflections.
A directional antenna will not reach a widely spaced group of moving targets as easily as
an omni-directional antenna can, or broadcast in every direction that way an omni-
directional antenna will, so there are situations were an omni is a better choice.
Directional antennas can be used in receiver/transmitter pairs to further enhance
directionality and range, and can also be used on a transmitter or receiver with omni-
directional antenna(s) on the other corresponding unit to create different combinations of
directionality in the system. They can also be used with a single transmitter in a pair
with a splitter to send the radio signal in two different directions (e.g. two sides of a
building with the transmitter mounted at the corner).
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Under special circumstances the 5632 8dBi panel antenna may be used with 5601 and 5611
in
pairs only
with the CTI # 5637 Antenna Splitter; contact CTI for details
