Coax Collinear for 70cm

This 70cm Coax Collinear Antenna was homebrewed one evening in the year 2008.

The job was made simple, thanks to N1HFX - OM Mike Martell and his detailed article 'Build A 9 dB, 70cm, Collinear Antenna From Coax'.

A view of the Coax Collinear for 70cm

All instructions were strictly followed.

A brass sleeve was soldered to the braid at the feedpoint and a SO-239 connector was used.

Both the ends of the antenna were waterproofed with epoxy.

SWR was close to 1.5:1 when checked at a power level of 50mW.

Signal strength with this antenna was 2-3 'S' points higher compared to that using a ¼ λ Ground Plane Antenna at the same height.

Related post: Direction-finding Yagi Beam for 70 cm
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J-Pole Collinear for 2m

A makeshift, phasing-coil variant of a 2m J-Pole Collinear was recently homebrewed.

J-Pole Collinear for 2m - details

It was fabricated with a single length of 20SWG copper wire and taped to a bamboo pole for rigidity.

The coil section was 64 turns close-wound on a 10mm mandrel and then stretched to a length of 300mm.

SWR measured close to 1.5:1 across the 2m band.

Antenna performance exceeded that of a normal J-Pole at the same height.

A 16SWG rugged version, encased in a PVC pipe, is in the works.

Related post: PVC-encased Vertical Antennas for 2m
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