Lectrosonics UH400a - Manual (Page 13)

Frequency Agile Plug-On UHF Transmitter
Troubleshooting
Before going through the following chart, be sure that you have a good battery in the transmitter. It is important that you
follow these steps in the sequence listed.
Symptom Possible Cause
Transmitter Battery LED Off 1. Battery is inserted backwards.
2. Battery is dead.
No Transmitter Modulation LEDs 1. Gain control turned all the way down.
2. Battery is in backwards. Check power LED.
3. Mic capsule is damaged or malfunctioning.
4. Mic cable damaged or mis-wired.
5. Phantom power not enabled for mic that requires it.
Receiver RF Lamp Off 1. Transmitter not turned on.
2. Transmitter battery is dead.
3. Receiver antenna missing or improperly positioned.
4. Transmitter and receiver not on same frequency.
Check switches/display on transmitter and receiver.
5. Operating range is too great.
No Sound (or Low Sound Level), Receiver Mod Level LEDs Are On
1. Receiver output level set too low.
2. Receiver output is disconnected; cable is defective or mis-wired.
3. Sound system input is turned down.
No Sound (or Low Sound Level), Receiver Mod Level LEDs Are Off
1. Transmitter gain (audio level) set too low.
2. Faulty microphone
3. Phantom power not enabled for mic that requires it.
4. Not enough current to power microphone. (Earthworks M30 is
only known microphone we’ve found to exhibit this issue.)
Distorted Sound 1. Transmitter gain (audio level) is far too high. Check mod level
lamps on transmitter and receiver as it is being used. (Refer to
the Operating Instructions section for details on gain adjustment)
2. Receiver output may be mismatched with the sound system or
recorder input. Adjust output level on receiver to the correct level
for the recorder, mixer or sound system.
3. Excessive wind noise or breath “pops.” Reposition microphone
and/or use a larger windscreen.
4. Transmitter is not set to same frequency as receiver. Check that
frequency select switches on receiver and transmitter match.
Hiss and Noise - Audible Dropouts 1. Transmitter gain (audio level) far too low.
2. Receiver antenna missing or obstructed.
3. Operating range too great.
Excessive Feedback 1. Transmitter gain (audio level) too high causing the limiter to
reduce the dynamic range which in turn causes feedback.
Check gain adjustment and/or reduce receiver output level.
(Refer to the Operating Instructions section for details on gain
adjustment)
2. Transmitter too close to speaker system.
3. Mic is too far from user’s mouth.
Rio Rancho, NM 13