I built a VHF one for our local SAR team in a small pelican box. We utilized 2 ICOM portables that we had with battery eliminators. 20 W duplexor from ebay and a 7AH gel battery. We use the repeater for standby events and other uses. Only issue we have had is heat. We now leave the lid open some if we cannot get it in the shade. I wanted to find some data type radios just to make it even more error proof. Right now they need to turn on both radios and controller, hence errors happen. The data radio idea is flip a switch and leave. Keep us posted on the outcome. I was thinking a similar project for when i go camping in an ammo can.