iScottybotty wrote: So, the controller is on 452.900 for example. If I had a radio handheld capable of transmitting, I'd then need to type in this frequency again and in the menu choose 136.5hz to open the squelch? That would then open the floodgates so to speak?
Or would I need to programme, 452.900 as the receive, 465.400 to transmit and in a menu somewhere 136.5hz to open the squelch?.
No, no tone is needed at all to hear either side.
My wife works at a location where they use a system available to anyone who applies to Ofcom & pays a few pounds for a 5 year licence. Sitting outside her place of work I can hear several other users on the same frequency. Each is using CTCSS.
CTCSS stops my wifes locations radios from opening the squelch when any other user transmits on the frequency they all share.
So I can hear my wifes location, plus all the other users with my CTCSS off. And unless I transmit on that frequency with the appropriate CTCSS tone for any individual user they will not hear me.
So my wife location for example has two departments within the same building using frequencies which are close to each other & others using exactly the same frequency further away & due to CTCSS, those who do not understand radio wonder why they get occasions when the radio signal is unreliable despite being within a small building. If they had a channel programmed with no CTCSS programmed, they would realise, the radio users the other side of the building interferes with them, as do other users on the same frequency.