I went from zero bars to 2-bars by putting a lexan window in the rear of my steel mailbox and attaching the PIR to the center of the aperture. My cam/bridge is 30’ line of sight away. After six months of mail service and flawless triggering of the Driveway Cam, the battery reading is still normal.
Note: with the window painted black, the signal dropped to one bar and was not reliable.
