My front porch light switch is operated by a Heath Zenith system that has a battery operated motion sensor/transmitter. You can place the sensor anywhere within range and it turns the porch lights on with motion after dark. You can also use the wall switch/dimmer. Nice compact system. Mine dates from 2005 and is no longer made. Recently it was not been working very well. When it works at all it is dependent on the temperature and/or maybe the humidity.
I found a NOS replacement set. Of course it is probably the same age as the one I have installed. Right out of the box the sensor does not work. It has an LED that blinks when motion is detected and this unit blinks all the time, motion or not. It’s bad. My old sensor seems to work OK, at least the LED indicates properly. So I installed the new wall switch and kept my old sensor. At first it was also erratic. The wall switch has a thin wire antenna that is supposed to hang down in the wall cavity. Of course my walls have fiberglass insulation and the outer wall has Tuff-R foil faced insulation board. So I pulled the antenna out of the wall and let it hang in the room. Ah Hah! Everything thing works great.
I would like to optimize as much as possible so I was wondering if I should solder on an extension to the antenna. Things like ham radios use antennas of specific length to work best. They are like full wave, half wave or quarter wave length as I recall and are quite long. I wonder if this setup also uses a specific length antenna. It is only about a foot long. I have no idea what frequency it operates at. Should I double the length to be sure or simply add a nice long wire? I can run the wire tucked in the corner of the door molding and it will be hidden fairly well.
Or just leave it alone and see how it goes?