Lectrosonics R400a - Manual (Page 19)

UHF Wireless Diversity Receiver
Rio Rancho, NM 19
Symptom Solution
RF Level is weak Receiver may need to be moved or reoriented.
Antenna on transmitter may be defective or poorly connected - double
check antenna on transmitter.
Improper length of antenna, or wrong antenna on transmitter or
receiver. UHF whip antennas are generally about 3 to 5 inches long.
UHF helical antennas may be shorter, but are often less efficient.
No RF Signal Make certain frequency switches on transmitter match the receiver
frequency setting.
Check transmitter battery.
Poor signal to noise ratio Transmitter gain set too low.
The noise may not be in the wireless system. Turn the transmitter
audio gain all the way down and see if the noise remains. If the noise
remains, then turn the power off at the transmitter and see if it
remains. If the noise is still present, then the problem is not in the
transmitter.
If noise is still present when the transmitter is turned off, try lowering
the audio output level on the R400A and see if the noise lowers
correspondingly. If the noise remains, the problem is not in the
receiver.
Receiver output is too low for the input of the device it is feeding.
Try increasing the output level of the R400A and lowering the input
gain on the device the R400A is feeding.
Distortion Transmitter input gain too high. Check and/or readjust input gain on
transmitter according to the LEDs on the transmitter and then verify
the setting with the audio meter in the main window.
Audio output level too high for the device the R400A is feeding.
Lower the output level of the R400A.
Bad frequency response or generally poor audio quality
Ensure the receiver is set to the compatibility mode that matches the
transmitter in use.
Note: A number of symptoms may be caused by a strong interfering signal on the same frequency. The easiest way to
determine if the transmitter and receiver are operating on a clear frequency channel is to switch off the transmitter and
see if the RF meter on the receiver drops to zero. If an interfering signal exists, the meter will indicate it. Refer to the
‘frequency coordination’ section to establish a different operating frequency.