Line 6 DIGITAL WIRELESS XD-V75 - Manual (Page 27)

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Note, For best performance, Line 6 recommends that no more than four receivers share a single pair
of antennas via looping through the BNC ports on the rear of the receiver. For the next group of four
receivers, use another pair of antennas. Alternately, use a Line 6 antenna distribution unit or other
RF distribution unit that is appropriate to the 2.4 GHz band to run multiple receivers from one pair of
antennas.
Note, Line 6 remote antennas are active and therefore require power through the coaxial antenna
cable to function properly. Make sure that any other RF distribution unit that is used can provide the
necessary power; consult the antenna specifications for details.
Remote Antenna Placement
The XD-V75 Digital Wireless system can be used with remote antennas, so that the receivers can be
located where convenient – even at a distance from where the transmitters are being used – yet the
antennas can be placed nearer to the transmitters for better RF reception. Remote antennas become
important especially when the distance is significant between the transmitters and receivers, there
are walls or other obstacles between them, or when the receivers are “permanently” mounted in an
equipment room or production vehicle and the transmitters are used at various and changing locations
and distances. Both omnidirectional and directional (cardioid) remote antennas are available.
To connect remote antennas to receivers, use low-loss 50-ohm coaxial cable with the appropriate BNC
connector on each end. Place the antennas with clear line-of sight to the location where the transmitters
will be used; the Line 6 model P360 omnidirectional and P180 directional active antennas provide the
convenience of mic stand mounting. Attach one end of the cable to the antenna, and run it the shortest
possible distance to the ANTENNA A / ANTENNA B connectors on the back of the receiver.
Measure the distance and set the gain to the appropriate setting on the antenna; 6 dB for 25 feet, 15
dB for 50 feet, and 26 dB for 100 feet. Once connected and with the receiver on, confirm that the blue
light on the front of the antenna is lit. Walk-test the area after the antennas are placed to make sure
that it is properly covered without interference or dropouts. Up to three additional receivers can use this
antenna by looping the receivers.
Note, As the RF signal travels through the cable to the receiver, there will be some loss of signal level,
which at greater lengths and with higher loss cables can be significant. With a passive antenna, use the
lowest loss cable you can find and try not to exceed about 15 feet of length. With an active antenna that
provides additional gain, set it to the proper amplification for the cable length, and try not to exceed
100 feet of cable.
When used properly, remote antennas can increase range and lessen dropouts and interference
conditions, compared with having the half-wave antennas directly connected to the receiver or front-
mounted in the rack. This is especially true when the receivers must be located in a non-line-of-sight
position or behind obstacles.
Omnidirectional antennas are best applied when the users will be transmitting from a wider area – in
front, to the sides, and even behind the antenna. Directional antennas provide greater signal strength
at the front of the antenna, and greater rejection of the signal at the rear – in the case of the P180,
a cardioid coverage pattern of approximately 90 degrees with a roll off to the sides. Use them when
the users are in a more confined area or not roaming as much. They can also be used to minimize an
interfering signal source by facing the back of the antenna toward the interferer and the front toward
the transmitters.
In some cases remote antennas can also allow you to use the transmitter’s low power setting to minimize
interference when transmitters are used very close together or two or more groups of transmitters are
used for separate productions that are closely located (such as in adjacent ballrooms or theatres). Just
make sure that the improved signal strength you receive from a closer and clearer position to the
transmitters is not overwhelmed by the losses of too long a cable run.