VK5DW – Cross Yagi Project

Here is my, VK5DW Danny, attempt at a 2m/70cm Crossed Yagi for satellite kit. I wanted something that would be easy to transport so it needed to break down and package down into a bag. And given I was going to build it so it would break down I thought I might as well see if I could build it in such a way that it could be used in a number of formats.

So what I came up with is this little outfit. It can be used in the following yagi configurations:

  • 4 element 2m/8 element 70cm Crossed
  • 4 element 2m
  • 5 element 70cm (I had fox hunting in mind)
  • 8 element 70cm
  • Each can be mounted on stand OR hand held

The extended boom hosts a counter balance, portable radio mounts, and breakout box for the LogiTech headset and remote PTT to plug into.

The way I made it collapsible was to make each of the elements as two piece connected through the boom by a M4 bolt. This bolt has an additional M4 nut placed ~10mm from the bolt head, inserted into the 10mm aluminum tube element with the nut flush to the end of the element. This is crimped with a ‘F’ Type RG59 crimping tool. The other matching element half has 2 M4 nuts inserted into the end, using a spare bolt to hold the nuts, and crimped in the same manner as the other side.

The bolts insert through the boom and the 2 halves of the element screw together. Where the boom is split it has a short section of ‘U’ channel that fits nicely into the boom. It is riveted into one section of the split boom and when slipped together is held by the bolts of a couple elements.

Build instructions are available here

The total kit includes:

  • The antenna assembly
  • 2 x portable radios (this allows for full duplex operation)
  • Stand (ex flood light kit)
  • Remote PTT
  • LogiTech PC Headset with boom mic
  • Boom extension with counter balance, portable mounts, and breakout box
  • Coax patch leads fixed to boom extension for stand operation
  • Spare coax fly lead for hand held operation
  • Padded extension handle for portable operation

Thanks for having a read,

VK5DW Danny