User Manual
System 9 Installation and Operation
6
System Operation
level before starting up the wireless system. Do not switch on the 
transmitter yet.
Receiver on...
Plug the power supply into an AC power source. The green Power 
indicator on the front panel will light. 
How to Make Operating Channel Changes
Press the receiver’s Channel Select Button repeatedly until the desired 
channel is reached.
Before turning on the transmitter, use the provided screwdriver to set 
the transmitter channel selector DIP switches (Fig. C on page 4 and 
Fig. D on page 5) to the same number that is displayed on the receiver.  
(If transmitter channels are changed while the transmitter is on, the 
Transmitter on...
When the transmitter is switched on, the receiver’s amber RF signal 
indicator will light. The transmitters have a soft-touch power switch. 
When the switch is set to “Mute” (red indicator LED), the transmitter 
produces RF with no audio signal. When the switch is “On” (green 
indicator LED) the transmitter produces both RF and audio. Excessive 
audio input to the transmitter will cause the receiver’s red AF Peak 
indicator to light.
Receiver Volume
Under typical operating conditions, the receiver’s volume control should 
be turned all the way up, with overall system audio gain adjusted at the 
Input Level Adjustment
Input trimmer controls in the transmitters enable you to maximize 
performance for a particular microphone or guitar sensitivity, or to 
adjust for different acoustic input levels. 
Adjusting Input Level - UniPak Transmitter
Slide the battery cover off the top part of transmitter and remove 
the screwdriver from its clip (Fig. D). Gently turn both the “MIC” 
(Mic Trimmer) and “INST” (Instrument Trimmer) controls to their full 
counterclockwise positions (toward “L”).
• Microphone: Adjusting input level
Gently turn only the “MIC” (Mic Trimmer) control all the way 
up (clockwise, toward “H”). Check for excessive gain by speaking/
singing into the microphone at typically loud levels while watching the 
receiver’s AF Peak indicator. If the AF Peak indicator does light, turn 
the “MIC” control slightly counterclockwise until the AF Peak indicator 
no longer lights with maximum audio input to the transmitter.
• Guitar/Instrument: Adjusting input level
Gently turn only the “INST” (Instrument Trimmer) control all the way 
up (clockwise, toward “H”). Check for excessive gain by playing at 
typically loud levels while watching the receiver’s AF Peak indicator. 
If the AF Peak indicator does light, turn the “INST” control slightly 
counterclockwise until the AF Peak indicator no longer lights with 
maximum instrument input to the transmitter. After adjusting input 
level, return the screwdriver to its clip and reinstall the battery cover. 
No further transmitter gain adjustments should be needed, as long as 
the input device and the acoustic input level are not changed.
Adjusting Input Level - Handheld Transmitter
Unscrew the lower body cover and slide it off, exposing the screwdriver 
and "LEVEL" (Gain Trimmer) control (Fig. C). Remove the screwdriver 
from its clip. Gently turn the "LEVEL" control to its full clockwise 
position (toward the side marked “H”), the factory setting. Check for 
excessive gain by speaking/singing into the microphone at typically-loud 
levels while watching the receiver’s AF Peak indicator. If the AF Peak 
indicator does light, turn the "LEVEL" control slightly counterclockwise 
until the AF Peak indicator no longer lights with maximum audio input 
to the mic/transmitter.
Ret
urn the screwdriver to its clip and close and secure the lower body. 
No further transmitter gain adjustments should be needed, as long as 
CAUTION! The small trimmer controls are delicate; use only the 
supplied screwdriver. Do not force the trimmers beyond their normal 
190º range of rotation.
Return the screwdriver to its storage clip when not in use.
Ten Tips to Obtain the Best Results
1.  Use only fresh alkaline batteries. Do not use “general purpose”  
  (carbon-zinc) batteries.
2.  Position the receiver so that it has the fewest possible  
  obstructions between it and the normal location of the transmitter.  
  Line-of-sight is best.
3.  The transmitter and the receiver should be as close together as  
  conveniently possible, but not less than 6' (2 m).
4.  Do not place the receiver antennas within 3' (1 m) of another 
  receiver or antenna.
5.  The receiver antennas should be kept away from any metal.
6.  A receiver cannot receive signals from two transmitters on the same 
  frequency at the same time.
7.  In the UniPak transmitter, the “MIC” or “INST” input control not 
  in use should be set to minimum.
8.  If the receiver output is set too low, the overall signal-to-noise ratio 
  of the system may be reduced. Conversely, if
 the volume control  
  of the receiver is set too high, it may over-drive the input of the  
  mixer/amplier, causing distortion. Adjust the output level of the 
  receiver so the highest sound pressure level going into the 
  microphone (or the loudest instrument playing level) causes no  
  input overload in the mixer, and yet permits the mixer level 
  controls to operate in their “normal” range (not set too high or 
  too low). This provides the optimum signal-to-noise for the  
  entire system.
9.  Turn the transmitter off when not in use. Remove the battery if 
  the transmitter is not to be used for a period of time.
10.  Unplug the receiver from the AC outlet when the system is not 
  in use.








