All About CTCSS and DCSS codes
Carrier Tone Code Squelch System (CTCSS) and Digital Code Squelch System (DCSS) are two mechanisms that radio users frequently use to reduce interference. Some call these "Privacy Codes" or "sub-channels", but they really are not, if you set a radio to recieve without the CTCSS/DCS code, it will receive EVERYTHING on that frequency/channel regardless of the CTCSS/DCS code being transmitted. Many argue that in an emergency scenario, or any time you are using radios from multiple vendors, it is best to NOT use CTCSS/DCS codes as they can be different between vendors. Personally, I still use them and just make sure that the actual values match (Hz not number). CTCSS and DCS are mechanisms to "squelch", or ignore an incoming signal unless it contains a matching tone (CCTCSS) or digital code (DCS). A receiver with just a carrier or noise squelch does not suppress any sufficiently strong signal; in CTCSS mode it unmutes only when the signal also carries the c...