I bought one of these antennas to see how well it works compared to the stock antenna. I didn't get any change in contacts. Since I don't really get many contacts because there really are so few anyway, the antenna doesn't really extend my range. Note: I get more mode-s, then ADS-B.
The advantage of this antenna though, is its grounded design. I live in tornado alley and that means we get a lot of lightning (we are having an electrical storm as I type, and all my antennas are disconnected from the radios). Not only do antenna's need grounding and have fuses in-line, you need lightning rods to attract lightning away from your antennas.
So, as with most things, curiousity compelled me to disassemble it. I pulled the two plugs (top and bottom, and pushed the antenna out the bottom to take a look.
First impression is very good. The whole antenna is placed in a schedule 80 PVC pipe (overkill, as a schedule 40 would be good enough). This PVC pipe will not flex. Then the antenna elements are covered in a thick shrink-wrap to keep out moisture/condensation and add to the rigidity. Without taking the shrink-wrap off I can see that this is a 10 (1/2-wave) element collinear, with a 1/4 wave stub at the top and at the base.
The construction is top-notch. I decided to not let my curiousity cause me to remove the shrink-wrap, as I can feel under it, that they seem to use a rod to make the length rigid, and place the mini-coax soldered elements against the rod. I don't know what the rod is made out of (obviously not a conductor), but it seems pretty firm.
This is a quality made antenna.
