I recently started running PiAware and bought the FlightAware ADS-B antenna. I live in a townhouse with a metal roof. The antenna is mounted on an antenna mount and sits about two feet above the roof.
I’m wondering if it would make sense to connect the antenna’s ground to the metal roof. I figure that should help reception, since it’s a large piece of metal (several hundred square feet, also connected to my neighbor’s). But I’m worried that it might create a ground loop that might cause problems and even fry the Pi (which is connected to mains power through a power brick, though not directly grounded).
Any thoughts? Should that antenna get a ground plane at all, or is it better left alone?
The collinear antenna doesn’t require a ground plane. Generally, the antenna with a coil in the center are the ones that need a ground plane. Most mobile antennas for example, or the ones that come with a dongle.
Both the antennas you referred to in your post are “collinear”. The first one is “coaxial collinear”, and 2nd one is “wire collinear”
The Flightaware antenna is a “wire collinear” and has a coil in the middle, but still does not require a ground plane. Here is the photo of an Flightaware antenna with pvc (or fiberglass?) pipe removed http://discussions.flightaware.com/post179553.html#p179553