MODEL UA870 UHF ACTIVE DIRECTIONAL ANTENNA
The Shure UA870 is an active UHF wireless directional anten-
na. It features a log periodic dipole array. When compared to an om-
nidirectional 1/2-wave antenna, the cardioid pattern provided by the
UA870 offers enhanced reception of the desired coverage area and
greater rejection of RF signals outside the coverage area.
To compensate for coaxial cable signal loss, the UA870 has an
on-board amplifier that offers user selectable 3 or 10 dB gain. The
gain setting is indicated by two LEDs. Remote 12 Vdc power for the
antenna amplifier is provided by a Shure U4 or ULX Receiver or a
Shure UA845 or UA844 Antenna Distribution System through the
connecting coaxial cable.
The UA870 can be mounted on a microphone stand, sus-
pended from the ceiling, or mounted to a wall using the integrated
swivel adapter bracket. The UA870 is weather resistant for use out-
doors. For best diversity performance, use two UA870 antennas.
INSTALLATION INSTRUCTIONS
1.
Determine the length of cable required to connect the UA870
Antenna to the U4 or ULX Receiver or UA845 or UA844 Anten-
na Distribution System.
IMPORTANT:
Always use low-loss 50 ohm cable, such as RG-8X or equiva-
lent. Shure UA825 7.6 m (25 ft.) or UA850 15.2 m (50 ft.) or
UA8100 30.4 m (100 ft) cables are recommended.
2.
Set the gain switch to the appropriate setting. If you are using
coaxial cables up to 7.6 m (25 ft.) long, select the 3 dB posi-
tion. If using cables 7.6 m (25 ft.) or longer, select the 10 dB
position. To access the gain switch, remove the cover of the
preamplifier box (printed side) by unscrewing the four screws
at each corner. Gain settings are marked on the pc board in-
side.
NOTE: The UA870 gain control is factory preset at the 10 dB
position.
3.
Connect one end of the antenna cable to the UA870. Then
mount the antenna so that it points toward the intended cover-
age area. See Figure 1.
2003, Shure Incorporated
27C8629 (Rev. 5)
Model UA870 UHF Active Directional Antenna
User Guide
4.
Connect the other end of the antenna cable to the U4 or ULX
Receiver or UA845 or UA844 Antenna Distribution System.
The gain LED on the UA870 illuminates to verify that power
is being provided to the antenna.
Always perform a "walk around" test to verify coverage be-
fore using a wireless system during a speech or perfor-
mance. Experiment with antenna placement to find the opti-
mum location for the UA870.
FIGURE 1
NOTE: For additional technical assistance, call the Shure
Customer Service Department at 1-800-434-3350. In Europe,
phone 49-7131-72140.
SPECIFICATIONS
RF Frequency Range
UA870A
. . . . . . . . . . . . . . . . . . . . . . .
UA870KK
. . . . . . . . . . . . . . . . . . . . .
UA870MB
. . . . . . . . . . . . . . . . . . . . .
UA870MC
. . . . . . . . . . . . . . . . . . . . .
UA870UB
. . . . . . . . . . . . . . . . . . . . .
UA870WB
. . . . . . . . . . . . . . . . . . . . .
Power Source
Remote 12 Vdc from coaxial cable connection to receiver or
antenna distribution system.
Power Consumption
UA870 (A, KK, MB, MC, UB):
0.81 W (12 Vdc)
UA870WB: .68W (12Vdc)
Antenna Gain
7 dB typical (on axis)
Amplifier Gain
UA870 (A, KK, MB, MC, UB):
Gain Switch at 3 dB: 3 dB ± 2 dB
Gain Switch at 10 dB: 10 dB ± 2 dB
UA870WB: Gain Switch at 3 dB (–2, +1.5 dB)
Gain Switch at 10 dB (–1 dB, +3.0 dB)
Third Order Intercept Point (3OIP) at output
More than 30 dBm
Reception Pattern
Directional; Cardioid
3dB Beam Width: 100 degrees
IMPORTANT:
782-810 MHz
838-862 MHz
800-830 MHz
774-782 MHz
692-716 MHz
470-900 MHz
Printed in U.S.A.