CTCSS and DCS: how modern squelch systems work in analog radio communication
In analog radio communication—whether in amateur radio, commercial two-way radios, emergency services or industrial PMR/LMR systems—unwanted noise and co-channel interference have always been fundamental challenges. Traditional carrier-squelch circuits open the audio path whenever an RF signal is present, but this includes static, distant stations, overlapping users and accidental key-ups. To solve this, modern radios use…


