Jeff found the right unit. It worked great, easy to install, and to my knowledge is still being used some 20+ years later. I have lots of Mennonite customers and it[s perfect for their application on their farms. I connect all of their greenhouses, house, shops, and barns for intercom and transferring calls. The SX5 was cheap and would buy as many as I could get my hands on. Problem is I cannot find them anywhere. Please keep me in mind if something does show up.
Thanks,
Al Dukes