User's Manual
4
U-81 OCTAVO RECEIVER OPERATING INSTRUCTIONS
1. Rack-Mounting The Receiver
The U-81 OCTAVO receiver has pre-drilled holes for rackmounting. Simply attach the
Rack Mount Ears (1) on each side and fasten with supplied screws.
Note: Do not mount the receiver in a rack directly above an amplier or other source of high heat.
This could degrade the performance of the U-81 OCTAVO. Always ensure adequate airow and heat
dissipation in any rack conguration.
2. Installing Antennas
If not rackmounting the receiver, the two Antennas (2a) can be mounted directly on
the Receiver Antenna Input Jacks (2b) on the receiver’s back panel. If rackmounting,
antennas can be front mounted on the Rack Ear Jacks (2d), after installing the jacks
on the Rack Ears (1) provided. Use the Antenna Connecting Cables (2c) to feed the
received signal to the receiver’s antenna jacks as pictured, connecting them from the backs
of the rack ear jacks to the receiver antenna jacks. The optimal positions of the antennas
are 45° from the receiver, so 90° from each other.
Note: In order to ensure optimum operation of the U-81 receiver, the antenna labeled “902-928MHz”
should be mounted on the right antenna jack on the rear panel and the antenna labeled “944-952MHz” on
the left jack. If front mounting, please make sure to follow these guides so the correctly labeled antennas
are placed on the corresponding front panel jack connecting to the rear jacks.
3. Powering The Receiver
Powering the receiver by plugging the provided 15VDC/1000mA adaptor into the
DC INPUT jack (3) on the back of the receiver; then plug the adapter into an AC outlet.
(Note: Any 15VDC source with 1200mA capacity can also be used.) Turn volume controls of all
channels counterclockwise for minimum setting. Once the receiver is connected to a
power source, press the power switch to the ON position, Power LED indicator (4) is
ON. The TX LEDs indicator (7) and AF LEDs indicator (8) on the front panel of the
receivers will not light up at this time, but only until one or more of the eight channels is
receiving a signal from your system’s transmitters. To turn OFF, press the Power Switch
(5) to the OFF position.
4. Mute (Squelch) & RF LED Display
The U-81 OCTAVO has a preset mute (Squelch) internally for each channel for
maximum range and performance. There is no need to adjust this. In normal condition,
the RF LEDs indicator (7) should be lit when a correct frequency is received from a
transmitter. However, when the RF LEDs indicator (7) is extinguished, the transmitter
is out of range for that given location, and the user should move closer to the receiver
to re-establish the radio link.
5. AF LED Display
The U-81 OCTAVO receiver is equipped with an AF LEDs indicator (8). The AF LED
indicator lights whenever an audio signal is being received from a modulated transmitter
signal. The AF LED indicator is not a peak level indicator so it can light continuously
during audio signal input to the transmitter.
6. Connecting Audio Outputs
(Using the UH-81 handheld or UB-81 bodypack transmitters)
• For microphone use, the xed Balanced XLR out (9) or the adjustable 1⁄4” MIX
out (10) can be used. The U-81 OCTAVO audio output stage of each channel is
congured for XLR balanced microphone level when loaded by a 600 ohm balanced or