Direction-finding Yagi Beam for 70cm

The PVC pipe/brazing rod construction, used in homebrewing this antenna, is the brainchild of OM Nathan Loucks WB0CMT (A Portable 3-Element 2m Beam - April 1993 QST).

All it requires is a length of 25mm PVC pipe, 2 end caps, 1.6mm brazing rod, a BNC socket, a piece of RG-58U coax and M-Seal epoxy sealant.

70cm Direction-finding Yagi Antenna

Element lengths used:

Driven element: 330mm end-to-end, Director: 305mm, Reflector: 355mm

Element spacing:

Driven element to director: 130mm, Driven element to reflector: 75/85mm.

Conversion of the driven element, from a straight dipole to a half-folded one, was an afterthought to bring the SWR down to less than 1.5:1.

70cm Direction-finding Yagi - detail of driven-element

A length of 18SWG copper wire was used for the conversion.

Related post: Wire Slim Jim for 70cm
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'Wire Slim Jim' for 70cm

This Slim Jim for 70cm was homebrewed using a length of 18mm diameter thin-walled PVC tube, 20 SWG copper wire, a BNC socket and ‘M-Seal’(epoxy sealant in dual component lump form).

The wire ends and the flange-type BNC socket are secured with self-tapping screws.

Sealing against water ingress is done with M-Seal.

70cm Wire Slim Jim Antenna

A low SWR (less than 1.5:1) was obtained with the feed point at 25mm from the lower end.

This antenna weighs only 90 grams.

Related post: Open Stub J-Pole for 70cm
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