Squelch - Sennheiser EK 3253 Instructions For Use Manual

Squelch

Pilot tone squelch
When set to stereo operation, the transmitter adds a 19-kHz
pilot tone to the audio signal. The receiver checks incoming
audio signals to see if the pilot tone is present. In the absence
of the 19-kHz signal, the receiver's audio output will remain
muted, even if a strong RF signal is present.
This prevents strong interfering signals from causing hissing
noise in the receiver when the transmitter is switched off.
Field strength-dependent squelch
Depending on the strength of the received RF signal, the
receiver's audio output is opened or muted. Via the "SQELCH"
menu of the receiver, the squelch threshold can be adjusted in
three steps (LO, MID, HI).
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