Shure UA874 [4/44] Antenna placement

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.

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.

Find More Information Online

For more information, visit http://www.shure.com

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.