https://ambientmemory.com/tags/radio/ Recent content in radio on Ambient Memory Hugo -- gohugo.io en-us Gavin Whelan Sun, 26 Feb 2017 20:46:59 +0000 https://ambientmemory.com/2017/02/26/manually-decoding-dcs-tone/ Sun, 26 Feb 2017 20:46:59 +0000 https://ambientmemory.com/2017/02/26/manually-decoding-dcs-tone/ Here I have a recording of FM decoded audio from a certain Motorola radio. In it you can see a continuous series of level changes, even when there is no audio (the fuzzy bits). This is the DCS (or generically CDCSS) used as a requirement to keep the squelch open. You can also see a continuous tone at the end of the transmission, just before the noise burst. This continuous tone is the squelch tail elimination (STE) which when the receiving radio hears, it silences the speaker output before the noise burst that happens just before the squelch cuts off.