On July 15, 2013 KG4GPJ, Larry gave a presentation on how to convert a typical “mag mount” antenna into a ground plane antenna.

MFJ 1401 – Ground Plane Conversion Kit
So the question is why would you want to do this?

• Much more efficient, therefore a more effective antenna
• Very easy to do – you don’t need to know all the technical stuff
• Easy to implement

Generally speaking mobile antennas use the vehicle’s body as the ground plane, however most mobile antennas are capacitive coupled to the vehicle therefore making the antenna less efficient.