Shure ua874V, User Manual, Page: 3 / 5

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Installation Instructions
1. Choose a location for installing the antenna that follows the proper
guidelines for cabling and antenna placement.
2. Mount the antenna to a microphone stand, or use the mounting holes to
suspend it from the ceiling.
3. For outdoor installations, use the mounting holes to secure the antenna
against wind.
4. Point the antenna toward the intended coverage area.
5. Use antenna cable to connect it to a wireless receiver or antenna
distribution system.
Important
• The antenna only operates with receivers or distribution systems that
provide 10–15 V DC bias.
• Lower the gain setting for short cable runs, or increase gain for longer
runs. Note that the quality of the cable, not just the length, contributes
to signal loss. A lighter-grade 50 foot cable may require more gain than
a 100 foot, low-loss cable. Contact the cable manufacturer for cable
loss specifications.
• Do not use this antenna for transmitting (such as with PSM
transmitters)
Selecting Antenna Cables
Use 50 ohm low-loss coaxial cable, such as RG-8U. Shure offers pre-
terminated antenna cables ranging from 6 to 100 feet.
Cable Maintenance
To maintain top performance for antenna cables:
• Avoid sharp bends or kinks in the cables.
• Do not deform cables with makeshift clamps, such as bending a nail
over the cable.
• Do not use in permanent outdoor installations.
• Do not expose to extreme moisture.
Antenna Placement
Use the following guidelines when mounting antennas:
• Receivers, amplifiers, and other accessories must be rated for use
within the same frequency range as the antenna.
• Mount antennas at least one wavelength (1.75 m) apart.
• Keep antennas away from metal objects.
• Position antennas so there is nothing obstructing a line of sight to the
transmitter (including the audience).
• Place antennas as close as possible to transmitter, such as to the side
of the stage (instead of a front of house location).
• For cable runs exceeding 25 feet (7.6 meters), an in-line amplifier
(Shure UA834) might be necessary to compensate for signal loss.
Important: Always perform a "walk around" test to verify coverage before
using a wireless system during a speech or performance. Experiment
with antenna placement to find the optimum location. If necessary, mark
"trouble spots" and ask presenters or performers to avoid those areas.
Setting Gain
The gain setting should only be used to compensate for the calculated
cable signal loss. Additional signal gain does not mean better RF
performance. Too much gain actually reduces reception range and the
number of available channels. This is because Shure receivers are
optimized to deliver the best performance when the sum of signal gain
and cable loss equals 0 dB. Additional gain just amplifies everything in
the RF range—including interference and ambient RF noise. It cannot
selectively increase the signal from the transmitter.
• Use the lowest gain setting necessary to achieve good reception of the
transmitter RF signal, as indicated on the receiver’s RF LED or meter.
• Only increase the gain setting to compensate for the calculated cable
loss.
• The −6 dB gain setting can be useful for applications with short cable
runs (25 feet or less) and where the distance between the transmitter
and antenna is less than 100 feet.
• Reduce gain if the antenna RF Overload LED illuminates—the signal is
strong enough, so gain is not needed.