i’m attempting to fix a a communication box that was given to me, i have determined that it has a bad audio transformer. but as i was looking at it i felt like it’s old tech and i could upgrade it and make it smaller inside so i can include a longer lasting battery. there is currently 2 ports for head phones 2 for a mic and one port for a external push to talk. the one mic is always live and it would seem the push to talk interrupts and allows you to then talk to the second person. currently the there is a switch for power, a switch for the speaker, a volume control for mic 1, volume control for mic 2, a battery indicator light, and the speaker mounted to the top plate.

my goals are to cut down on pcb size (the current size is 3.5″x3.5″)

include a 12volt rechargeable battery setup

while keeping the same functions

any help would be appreciated and if there is a board like this i could buy that works to but i would like to build it