The newer systems are "semi Wireless" as on the Late model Montana's. The pick up is on the front cap of the camper and it is hard wired from there to the rear of the unit. It is only wireless from the xmitter to the monitor which sounds like the one you describe.If I were to buy one now I would go wth the "semi wireless" system. Check out
www.rvcams.com and see if theirs is like the one you saw.