Indicators and Settings

① DC POWER/RF OVERLOAD

Green: Indicates it is receiving power from the antenna input on the receiver or combiner.

Red: Signal from the antenna (at the TO ANTENNA input) is too strong. Remove the inline amplifier or move it further down the cable run.

② GAIN

Set the gain switch to +6 dB for shorter cable runs, and +12 dB for longer runs.

RF Overload

RF overload can occur at the input to the inline amplifier or at the input to the receiver. An overload at either point degrades the signal.

When there is an RF overload indicator on the inline amplifier, the amplifier might not be necessary, or it should be placed further down the cable run at a midpoint between the antenna and receiver. The gain switch only affects output gain, and cannot compensate for input overload at the amplifier.

If there is an RF overload signal on the receiver, reduce the gain on the inline amplifier, or move it further up the cable run so there is more cable between the receiver and the amplifier. Note that the overload level for the amplifier might be greater than that for the receiver input, so it cannot be used to indicate whether the signal will overload the receiver at that point in the cable run.

Installation

Connect between the antenna and receiver (or antenna distribution system), as shown. The DC POWER LED illuminates green when the receiver is powered on.

• Use Shure low-loss coaxial antenna cable (or any 50 ohm, low-loss cable.
• 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.
• Active antennas, such as the UA874, have a built-in amplifier, and may not require additional amplification.

Caution: Use only Shure antenna accessories to ensure the best operation. Do not use splitters, combiners, or antennas that provide a DC ground. If necessary, use a BNC DC block device (compatible with the receiver RF band).

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 resulting signal level at the receiver (cable loss plus amplification) should be within ±5 dB of the original signal level at the antenna.

Specifications 

Certifications

This product meets the Essential Requirements of all relevant European directives and is eligible for CE marking.