Open-stub J-Pole for 70cm

Telescopic whips and an old terminal block insulator make this open-stub J-pole for 70cm.

70cm open-stub J-Pole Antenna
The stub portion of the driven element is of 3/16" copper tubing (if only to make up for the shortage in length!).

The dimensions are: Driven Element - 495mm, Stub - 165mm and Spacing - 16.5mm.

70cm open-stub J-Pole Antenna - Schematic
The elements are wired to a BNC socket mounted on the block.

SWR at 435MHz is less than 1.5:1.