Portable buddypole type dipole antenna by ZS1JHG

For backpack / portable use an antenna needs to be light and easily setup and perform efficiently. Having tried vertical antennas with poor results both homebrew and commercial I had a go at building a buddypole type homebrew dipole.

The centre connector and coil formers were made from pvc sprinkler risers and pvc end caps from plumbing supplies . The coils for 40m using thin speaker wire on 8 inch long by 1/2 inch diam sprinkler risers took about 78 turns of 22 AWG speaker wire to get a GDO dip at 7.100 Mhz. The end caps were drilled for 8mm bolts and nuts with star washers and crimp on lugs attached to the outsides of the caps, the  caps were then screwed onto both  the coil ends.

The connecting arms were made from aluminum tubing with 8mm threaded rod cut to size and clamped with S.S. hose clamps holding the threaded rod inside both ends of the slit tubing. The coils are connected to the centre connector and connecting rods with Coupler nuts as are the 72 inch stainless steel telescopic whips.

The centre connector (a 2 inch pvc sprinkler riser)  has a small aluminum plate to carry the SO-239 socket , bolted to its centre.

The attached photos give an idea of the construction and the neat bag is from a  Barbecue set. My son uses the Barbecue tools so no waste here.

The feedline RG58AU is fitted with an RF choke ie ferite beads or coil your feedline up 7 turns about 6 inches diameter.

After building the antenna I set it up on a 6 foot ladder in my lounge and was amazed at the reception compared to the verticals I had tried and by rotating the antenna you can peak up signals and null noise. Additional coils need to be made for 20m using 3 inch risers wound with about 20 turns 22 AWG speaker wire and use a GDO to  check resonance at your 20m selected centre frequency of choice.The mast for your dipole can be made from PVC /Aluminum screwed together see article by Phil Salas on verticals at. http://www.ad5x.com/presentations.htm 

Photos Below :