You can often get tone boards or old equipment containing them for a few dollars at a ham fest if you don't have time to make one up. A very simple encoder can be made with a LM 565 pll chip and a few components.
Thanks for the video! Dave Jones brought me here. We use tones on our radios at work. We have a FCC license for certain frequencies and tones. I always thought it was funny that while we used a tone, we could still sometimes hear school buses or taxi cab dispatchers talking, but they never seemed to acknowledge that they heard us. I thought it was odd since we were operating an aircraft, so they should definitely hear our aircraft transmitting if we could hear them from our ground station. Does that make sense? If we could hear them, that means they were using the same tone as us, right? Or is that not true? Shouldn't they hear us too then? Maybe they couldn't hear our ground station, but they should definitely hear our aircraft, considering that we could often hear our aircraft from 20 miles away (even if the aircraft couldn't hear us on the ground some times). Or is there something which I am not understanding? Thanks! P.S. What a loser.
For most modern stuff you an set a transmit and receive tone. Those two can be different. Receive squelch will only open for a transmitter sending the same tone, and vice versa. You might not want to use one or the other in some circumstances... so any combination of who can hear who could potentially happen. I don’t know what actually happens on commercial bands though.
