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Tonsoffun

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Revision as of 18:36, 21 February 2008 by Tonsoffun (talk | contribs)

This Log Periodic beam is very easy to build yourself with the available material at your local hardware store. The design is from a Haruteq Scanner Book I had and decided to give it a try. It works great on all scanner bands when you need to pin point and maximize your signal. The design shown is uni-directional and suitable for mounting on a tower or mast with a rotor to change it's listening area whenever you like.

The specifications shown for the LP has an overall gain of about 8 to 10dB from about 130 Mhz to 900 Mhz, and has a 50 Ohm impedance. Below 130 Mhz it actually performs quite well on local signals and strong skip, although no miracles can be expected.

Parts you need to make this antenna:

  • Two lenghts of aluminum (#1 on drawing below)to make the boom (preferably square or even angle) 1 meter long (3' and a bit)and diameter about 1/2" to 3/4".
  • Antenna elements should be about 3 to 4mm (about 1/8") Strong enough that the wind can not bend it. The elements that I put on were 1/4" aluminum to make it really beefy. All together you are going to need about 6 m (20')of the element material.
  • U-clamp (#3 on the drawing)
  • Pieces of wood or plexi glass to keep the booms seperated
  • Small wire to jumper the back of the LP
  • Some very good coax to hook up to your scanner


LogPerodic.jpg