Bob Nixon wrote:
The UART that I used to install back in 73 was a yellow colored snap-
on or Velcro battery powered emergency location crash transmitter box.

Aha! Perhaps you mean AN/URT beacon set radio, right? As in this:

http://www.tpub.com/1ase2/43.htm

To me, UART means "Universal Asynchronous Receiver/Transmitter" and was a
handy chip to have when one wanted to convert serial bit stream to parallel
byte streams and vice versa (as in modems and such.) Sure beat wiring
together (and debugging) discrete TTL chips to accomplish the same thing.