Thank you so much. I appreciate it.Pulsing is hardly difficult - turn it ON, wait a bit, turn it OFF, wait a bit - repeat.
You could obviously use PWM to do it if you wanted as well, as long as you can adjust the frequencies.
However, presumably the transmitters aren't connected to the Uno, and the Uno is trying to detect them?.
In which case you could use 555's to pulse them.