Why do we use CTCSS tones? One of the reasons repeaters use CTCSS tones is that they often operate in environments where there is a lot of interference. So, even though your radio may be transmitting and receiving on the correct frequencies for a particular repeater, you won’t be able to access the repeater if you’re not also transmitting the CTCSS tone the repeater has been programmed to respond to. The signals that a repeater (or radio) will receive are signals with a specific sub-audible tone, called a CTCSS tone, that has been added to the signal. The repeater may require a proper DCS tone from your transceiverĬTCSS stands for continuous, tone-coded squelch system, and is a technique used to allow repeaters-and radios-to receive particular signals and reject others.The repeater may require a proper CTCSS tone from your transceiver.QUESTION: Which of the following could be the reason you are unable to access a repeater whose output you can hear? There’s even a question on the Technician Class exam that addresses this issue, question T2B04:
One of the things that many newcomers to FM and repeater operation fail to do when programming a radio is to program the CTCSS tone properly.
