Setting Up Panel Directional Antennas, page
3
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Polarize antennas the same way.
Mount the antennas with matched polarity markings
pointing up. The antennas in the figure below are polarized vertically (note the “VERT
POL” marking on both units is pointing up).
Test the reception of the system.
Once you have your system set up, start your DMX
source (console, DMX tester, etc.), initiate wireless DMX broadcasting, and check the
received signal strength at the receiver. The SHoW DMX Receiver displays received signal
strength periodically in the Main menu or continuously in the Misc Settings menu, so you can
monitor received signal strength while you fine tune the position of the antennas. Received
signal strength is displayed as –dBm and -40 dBm is the best possible value, with higher
numbers being weaker than smaller numbers; -40dBm is stronger that -50dBm.
•
Adjust the height and rotation
of the antennas to optimize reception.
•
Check for obstacles between the antennas.
One of the most insidious obstacles to RF
is the human body. Be sure and consider your audience location when setting up your
system, and locate the antennas so that audience members won’t come between the
antennas.
As you are setting up and adjusting your system, note what happens to
received signal strength when you grasp an antenna to adjust it.
Another common
obstacle is glass; some window glass will block radio waves. If you want to broadcast out
a window, use a cable to put the antenna outside of the window. CTI panel antennas are
rated for outdoor use.
•
Test both vertical and horizontal polarity
. Sometimes, one will work better than the
other because of environmental conditions or due to the presence of other wireless
systems in the area. If there are other 2.4GHz wireless systems operating within range
that are interfering with your SHoW DMX system (or being interfered with by your system)
you may be able to significantly reduce that interference by changing the polarity of your
system. Radio systems are frequently setup by default with vertical polarity, so changing
your system to horizontal polarity may significantly improve things for all of the systems
within range.
