Listen Technologies LR-500 - Manual (Page 33)

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LR-400 Squelch
Squelch
The purpose of squelch is to mute the audio output of your receiver when the
signal from the transmitter is turned off or is too weak to be received. Without squelch you
would hear radio noise in your earphone. The squelch on your receiver can be adjusted so that
it will mute the audio on different RF signal strengths. This is useful as follows:
• To ensure that users don’t hear transmissions from other transmitters, set the squelch setting to
the highest level that doesn’t squelch the receiver.
• If the receiver is going to be close to the transmitter (i.e. in a classroom), setting the squelch
setting high so that when the transmitter is turned off it immediately squelches and ignores
transmitters in other rooms.
• If you are in an area that has a lot of inference, you may want to set the squelch setting to a
high setting to ensure the interference is not picked by the receiver.
• If you need the maximum amount of range, you may want to consider setting the squelch
setting to a low level (0, 1 or 2).
CAUTION: When setting the squelch level low the reliability of squelch function is comprised.
This will cause radio noise to be heard in the earphone and there is a possibility of
hearing damage.
Squelch Programming Instructions
Squelch Programming
To enter Squelch programming mode
• Turn the unit off
• Press and hold the seek button; while still holding seek turn the ON/OFF dial to turn the
unit on.
• Release the seek button when the Listen name disappears and a two digit display is seen.
To adjust the Squelch level
• Use the Channel UP and DOWN buttons to raise or lower the squelch sensitivity settings.
• Lower numbers mean that a less powerful and possibly noisy signal will be heard, but you
can have a longer range.
• Higher numbers mean that a more powerful signal with no noise will be heard, but you may
have a shorter range.
• Once the desired squelch setting is found, press “seek” to exit the squelch programming
mode.
Squelch setting 00 is no squelch; this effectively disables Squelching capabilities of the receiver.
Squelch setting 20 is maximum squelch sensitivity; you must have a very strong and stable RF
signal for the unit to not engage the squelch feature.
Adjusting the squelch setting will keep your LR-400 receiver from picking up noise when the
transmitter is not transmitting, or when you lose the signal by being out of range or if
encountering interference.
Note: For squelch settings 1-3, the squelch function is slow which allows for maximum
transmission range. For squelch settings 4-20 the squelch function is fast to ensure little
radio noise is heard during the squelch function.
(The Listen SQ™ feature is not squelch, please refer to page 33 for information on Listen SQ™).