Bob Archer Sportcraft COM Antenna

I have three issues with the installation of this Bob Archer Sportcraft COM antenna:

  1. The wing tip's inherent contour is not conducive to vertical polarization. I need to determine the optimum installation geometry.

  2. In order to maximize vertical polarization, I may not be able to ground the antenna traditionally...I need to know what the next best way of connecting the antenna to airframe ground would be (i.e. grounding strap, etc.).

  3. The RV-7 wing tip has a built-in lighting notch, which is different from the older wing tip design where lights would be installed closer to mid-chord. I need to know if routing position/strobe light wires along the front edge of the antenna is still critical if those wires would otherwise NOT CROSS the antenna.

Here are my comments and observations...

Unlike older wing tips, the new RV-7 sheared tips have a relatively flat bottom. This doesn't lend to vertical polarization at all.

What I believe would be ideal is something like this, where the antenna is attached to the bottom of the wing tip and then bent in an arch up to the top like this...

Here's a view from the aft, and you can kind of see what I'm suggesting.

The other alternative would be to install the antenna along the top surface of the wing tip, and let it curve down from there. More vertical can be established that way...but in order to maximize the vertical, the antenna would need to be installed a few inches outboard from the open end. Grounding the antenna inherently would not be possible. Would a simple ground strap connected to the airframe suffice?

In the installation instructions, it mentions that lighting wires should not cross the antenna, but rather should be routed along the leading edge of the antenna through the clips. Makes sense. But in my case, the lights are installed at the leading edge, and I could install the antenna well behind them. Is it still critical to route the wires along the antenna, even though they wouldn't CROSS the antenna? I could easily install the antenna several inches aft of where it appears in this photo.

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Dan Checkoway ()