Old radio as buddy box
I am getting back into RC and am trying to use as much of my old equipment as possible. I am using an old Futaba FM radio and want to teach my son to fly. I have some old Futaba AM radios. I was wondering if I could use one of those as a buddy box tethered to my FM Futaba? If so, how? If not, what options do you recommend on a budget?
Futaba FM is a TX6A
Futaba AM is FP-T4NBL