The central section of the DK7ZB elements
Another antenna being built is a 2-element 20-meter Yagi based on the DK7ZB design. The photo shows the Teflon element mounts with their center sections. A duralumin plate is slid onto the boom and secured with U-clamps.
The radiator is divided into two halves; the center section is made of wood—a planed shovel handle. The wood is coated with a sealant to maintain its insulating properties even in inclement weather. A box with a connector and the ends of the adaptor cable is mounted above the center. It should be finished this weekend.
Both the reflector and the radiator will then be extended to the desired length using thinner tubes, which will be slid into the central sections and secured with self-tapping screws and hose clamps (SK straps).
If the delivery of materials isn’t delayed and my work schedule allows, the antenna will be completed and calibrated within a week.
Box with connector and adapter cable
Update February 7: The next photo shows a close-up of the finished box. The PL connector is mounted through a metal plate, which will ensure contact with the boom once installed.
Coaxial cables exit the box through grommets. The braids are twisted together, tinned, and then insulated with heat-shrink tubing.
The coaxial cable is coiled into a circle with a diameter of about 25 cm and secured with electrical tape. The ends of the cable are soldered to solder lugs, creating a high-quality electrical connection to the radiator. The box is then sealed watertight.