Listen LR-100 Series, Руководство пользователя

Страница: 18 / 32

14
Speci
fi cations
Speci
fi cations
Programming
Squelch Adjustment
Squelch
The squelch adjustment is important to ensure the receiver audio is muted when no signal is present. You want to
set the squelch adjustment for the highest setting without squelching the incoming signal.
To set the squelch control:
Turn the transmitter OFF.
Listen to the receiver audio on the speaker or headphone. Turn the audio level down in the beginning.
Adjust the squelch adjustment clockwise until the squelch LED goes off (not illuminated). You will hear radio
noise now. This is the audio you want to squelch (mute) when the transmitter is off.
Now adjust the squelch setting counter clockwise until it squelches (mutes). This is the minimum
squelch setting.
Now turn the transmitter on. Adjust the squelch setting counter clockwise until the unit squelches. This is the
maximum squelch threshold. Please note that if you are close to the transmitter, you may not be able to find
the maximum squelch threshold due to the high RF signal of the transmitter.
Set the squelch adjustment between the maximum and minimum squelch thresholds, keeping the following
in mind.
Minimum squelch threshold. By adjusting the unit near this threshold, you will maximize the probability
the unit will NOT squelch when the transmitter is on. However, you also run the risk having the unit NOT
squelched (and resulting radio noise coming through the system) when the transmitter is off. You may
experience unsquelching of the receiver by interference as well.
Maximum squelch threshold. By adjusting the unit near this threshold, you will greatly increase the chance
the unit will squelch when the transmitter is off AND you will minimize the probability that the unit will be
unsquelched by interference. However, you are also increasing the chances that the signal coming from
the transmitter will be squelched. Thus, if the RF signal from the transmitter dips just slightly (someone walks
in front of the antenna), you will experience momentary squelching of the audio.
CAUTION: Ensure proper setting of the squelch adjustment to prevent user ear damage and unwanted radio
noise. Users will find unsquelched receiver noise very objectionable.
6