Bandhopper

The SCOTIA Bandhopper, a multi-band mobile vertical antenna, offers a unique sliding coil design for rapid band changes across 10m to 80m. Drawing inspiration from the classic Webster Bandspanner, this design improves efficiency through near-center loading, theoretically achieving up to 2.25 times greater radiation resistance than base-loaded counterparts. The antenna, extending to approximately 10 feet on 80m, utilizes a 5-foot fiberglass tube with an internal loading coil and a 57-inch tapered steel whip, allowing continuous tuning across bands without changing coils or whip sections.

Field results from GM3VLB and the SCOTIA team, based on over 40 years of /M and /P operations, indicate the Bandhopper significantly outperforms shorter mobile whips. Its slim profile minimizes drag, making it suitable for sustained motorway speeds. The design incorporates a novel "fixed spring contact" arrangement for the variable inductance loading coil, with two sets of contacts for 10/12m and 15-80m. Construction details are provided, including materials like boundary marker poles and specific wire gauges, with an estimated build cost of £20 or less, depending on junk box availability.