Do you have a mobile antenna for that new car but don’t want to drill any holes? Here’s a great solution that adds the convenience of antenna matching built right into the mount. For years I’ve tinkered with electronic projects at home. Two things have started to impact the fun: a harder time focusing up close (since I turned 50) and the fact that parts are getting smaller. One way around this is to concentrate on physically larger projects—like antennas and related items. I needed a simple antenna mount that could easily attach to my new Volkswagen Beetle without drilling holes. I wanted this antenna mount to support most mobile HF antennas, especially a Hamstick or Carolina Bug Catcher, since these are my current antennas. Additionally, I wanted the mount to include internal capacitive matching which is normally required for short antennas.
The VW Beetle Mobile Mount
The Volkswagen New Beetle has a heavy steel “loop” under the right rear part of the car, and this loop is bolted into the car frame. This is a tie-down loop used for new vehicle transport and it is present on many newer vehicles. It’s an excellent place to attach an antenna mount. I had a couple of scrap pieces of 1/4 inch thick aluminum rack channels and cut them to the dimensions shown in Figure 1. The completed mounting bracket is shown in Figure 2. This is a sturdy mount and a much larger antenna could be mounted on it with no problem. Base Matching for Mobile Antenna When any antenna is properly resonated, you will see a total resistance composed of the radiation resistance, coil losses and ground losses. For short antennas, the radiation resistance is very low—on the order of 2 to 3 Ω for a center loaded 40 meter antenna. Assuming you have reasonable coil and ground…

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