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2M lightweight Yagi

To gain some more experiance in VHF antenna building I build last year two 4 element 28Ohm Yagi as described on the pages of DK7ZB. Quite pleased with the result I used them for more then a year when I replaced them with a 9 elm Tona Yagi.

This year I'm more into fieldwork and backpacking, so I wanted to build a compact and especialy lightweight Yagi. DK7ZB has a good article about PVC yagi's especialy for fieldwork and backpacking (link). Based on the 4 elm 1m boom 50 Ohm design I build a fieldwork yagi as shown in the pictures below.

I used :

  • 4 x 1 m 6mm aluminium tube which fit in 8mm aluminium rods (making it easy to assemble  and take along).
  • 1 x 1m 8mm aluminium tube
  • 1 x a piece of plexiglass rod (massive)
  • 1 x 2m 19 mm PVC pipe (only 1.1m used)
  • 5 x clamps for 19 mm PVC pipe
  • 1 x box
  • 1 x BNC chassis part
  • 1 x 1m RG-174 coax (for the choke)
  • a handfull of M4 material

 

I used a lathe to model to plexiglass rod to make a holder for 2 x 7 cm 8 mm tubes.


Cutting the top of 2 of the clamps to mount underneed the box.

Make 3 tubes with a length of 15 cm of the 8 mm tube. Drill a hole in the center of 4 mm to mount the small tube on one of the clamps.

Mouting the 2 special clamps underneed the box.

Drilling holes on the correct locations on the 19 mm PVC tube and mount the camples (4 mm is the minimum, but 4.5 mm gives a little extra place to move around)

It's getting together.

Close up of the choke. aprx 40 cm (shield) around a 19 mm PVC tube. Oh, and also I drilled and made a M2.5 thread in the plexiglass tube holders.

First test : from almost nothing (S0 . . S1) on my FT60e (the backyard isn't the best place to QSO on 2m) with the original antenna to S6 . . S7 signal on the repeater PI3TWE with the setup below.

 

Yep happy OM :-)


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