Shure UA874 Manual De Instrucciones página 4

Antenna Placement
Use the following guidelines when mounting antennas:
• Antennas and receivers must be from the same band.
• Mount antennas at least one wavelength (two feet) apart.
• Position antennas so there is nothing obstructing a line of sight to the
transmitter (including the audience).
• Keep antennas away from metal objects.
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.
4
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.
Calculating Gain Settings
To calculate the required gain setting, obtain the cable manufacturer's
specification for signal loss. The rated loss usually varies with RF
frequency in addition to cable length.
Multiply the per 100 feet rating of the cable by cable length to determine
signal loss, and add gain as necessary to compensate. For example:
a 50 ft. cable with rated loss of -12dB per 100 ft. would calculate as (-
12dB/100)*50 = -6dB and require +6dB of gain for a sum total of 0 dB
loss.
Find More Information Online
For more information, visit http://www.shure.com