They use the ILS 13 approach heavily at BTR. I've got a glide slope, but had no way to locate the outer marker other than GPS. I noticed that marker beacon receivers are all over eBay for little money, so, I bought a nice one and an antenna to go with it. It's old school, but so am I. When I trained there were MMs and FMs behind the OMs. I miss those "-.'s" and "...'s", but at least I can hear "---" when I cross the OM and start the stop watch if the GPS lets me down. And, the flashing purple light is kind of festive. John