T4B03

AMATEUR RADIO PRACTICES · Operating controls: frequency tuning, use of filters, squelch function, AGC, memory channels, noise blanker, microphone gain, receiver incremental tuning (RIT), bandwidth selection, scanning function; Digital transceiver configuration; DMR code plugs and talk groups

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How is squelch adjusted so that a weak FM signal can be heard?

ASet the squelch threshold so that receiver output audio is on all the time
BTurn up the audio level until it overcomes the squelch threshold
CTurn on the anti-squelch function
DEnable squelch enhancement

Why Squelch mutes the receiver audio until an incoming signal is strong enough to cross a threshold you set. A weak signal may not be strong enough to open a normally set squelch, so you back the control off until the rushing noise is heard continuously, meaning the gate is open all the time. With the squelch open you will hear the noise, but you will also hear the weak station when it transmits.

Watch out Raising the audio (volume) control does nothing to the squelch gate, it only changes how loud the already unmuted audio is. There are no functions called anti-squelch or squelch enhancement, those are invented names.

Squelch gates the audio, volume only sets loudness. Weak signal? Open the gate until you hear hiss.

HamSandwich explanation, first draft. The question and answers are the NCVEC text.

T4B03

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