Setting Up Panel
Directional Antennas
The CTI range of directional panel antennas can significantly improve performance in a SHoW
DMX wireless DMX/RDM system, providing they are set up correctly. This document will
provide you with a number of techniques for effectively setting up and using panel antennas.
In general, it is best to setup your system well in advance of the show, and to plan to do some
testing and adjustment in order to optimize system performance. Whenever possible plan
your setup/testing time for the same time of day when your show is scheduled.
Panel antennas
are basically flat box shaped units, and radiate primarily from their front
“panel” surface. These antennas produce a relatively wide beam of radio waves that can be
aimed toward targets and away from things that
might cause problems. The CTI # 5632 8dBi
Panel Antenna (pictured) has a 60º beam
angle, meaning that most of the antenna’s
energy is shaped into a 60º wide beam (see the
beam pattern near right), and much like a light
fixture with a 60º beam angle, this antenna can
be focused at a desired target or group of targets.
Cables:
CTI panel antennas are provided with a short (12”) tail with a standard RF “N” female
connector, so an adapter such as the CTI # 5638 N to RSMA adapter is required to connect
the antenna to a CTI SHoW DMX Transmitter or Receiver. Extension cables may also be
used to locate the antenna some distance from the Transmitter or Receiver. All cables,
whether short adapters or longer extension cables, must be properly constructed from
materials intended for RF applications. Cables that are made from improper components or
are poorly assembled can impair or completely block radio transmissions.
All cables will attenuate the signals to the antenna to some degree. For short runs the
attenuation/loss will be insignificant with any good RF rated cable, but if longer cables are
needed, a special low-loss cable should be used. Low loss RF cable materials are typically
thicker and less flexible than the standard cables.
RF cables must be carefully installed. Overly tight bends will increase attenuation, as will
excessive numbers of bends. Excessive compression of the cable will also add attenuation,
so cable ties should be used carefully.
Attenuation and bend specifications for CTI RF cables are given in the table below:
Cable Type
Attenuation,
dB per 100'
Minimum
Radius, Single
Bend
Minimum
Radius,
Multiple Bends
Number of
Bends Max
CTI 5638 N to
RSMA Adapter
19 .5" 2" n/r
LMR 195-DB
19 .5" 2" n/r
LMR-400-UF
6.8 1" 4" n/r
Andrew FSJ-50
6.78 1" 1" 30
