Re: Oehler M43 Acoustic Target
It is best mounted on a seperate stand just in front of your target frame so vibrations don't transfer from the backer to the sensors and falsly trigger them. A cardboard backer with it hanging on the target frame works well, although I still compare target coordinants with those on the paper target as it will be off once in a while from a false trigger, you just don't ever have that problem with a seperate stand though. I don't have a private range I can leave the stands set up on like some folks do, which would be SOOOOO NICE!
I have a coat hanger wrapped through the top aluminum sensor holder shaped like the hook at the top on a coat hanger that I hook over the top of the cross brace on my target frame. Then I use electrical tape to wrap around and fasten to the lower PVC tube and the bottom cross brace, which runs parallel just below the PVC pipe.
I've used mine at 300 yards without an additional amplifier. I bought mine with probably 500-600 yards of wire on one of the reels but cut it back to a little over three hundred yards worth. It worked fine with however much wire was on it, so it will get a signal through a hell of a lot more wire the 200 yards that Oehler says.
Don't ever use sheetrock as a target backer, way too much noise and vibration transmitted to the sensors. Sound travels through wood or sheetrock "faster" than it does through air, this is why the sensors trigger before the mach wave actually triggers them and creates BAD coordinants. A seperate frame to mount it on is the very best setup, no questions asked. That said, Ken Oehler has his fastened to a target frame with a plywood backer and it works fine. I've tried plywood, it does work well, it or cardboard.