Firstly no way that’s a Cab-1L if it’s 15 years old. The original Cab-2 is barely that old. Easy way to tell the difference between then the original Cab-1 and Cab-1L is the original is grey plastic and has a external antenna the new Cab-1L is Blue plastic and no external antenna.
No matter witch one you have easy way to know of the base is getting commands from the remote is anytime a command is sent the red light on the base should blink.