THE COKE LOOP
The Coke Loop is a Small Magnetic Loop Antenna tuned by a trombone-style variable capacitor made with standard soda cans.
In Brazil we have the Coca Zero and the Coca Light versions of Coke. The Coca-Cola Zero can is shorter and wider and the Coca-Cola Light can is longer and thinner.
The loop ends are connected to the fixed Coca Zero (larger) cans. The moving trombone variable capacitor portion is made with Coca-Cola Light cans screwed to a piece of double-sided PC board.
The PC board is also screwed to the moving part of an injection syringe that is connected to another injection syringe by a plastic flexible tube filled with water. This makes a hydraulic remote tuning system to adjust the antenna resonance point.
The loop is made with a section of 112 inches of standard coaxial cable with PL-259 connectors on the ends that attach to the tuning system unit.
The excited loop is made from a 22.4-inch section of solid electric copper wire that is connected to a 2.5 meter section of coaxial cable for connection to the transceiver. The Coke Loop covers 12 meters, 15 meters, 17 meters, and 40 meters.
To make the loop work on 40 meters, I use a 150 pf fixed capacitor with alligator clips in parallel to the trombone variable capacitor.
COKE-LOOP CONSTRUCTION DETAILS
AHD ALEX (Alexandre Grimberg).