Details for halfwave dipole for an 868MHz band are quite simple:

  • two 0.8mm copper wires (used for welding) cut to 77mm and solder to the end of coax cable. Here I've used RG178
  • put that thing into a 3D printed casing
  • put antenna tubes around wires. I got mine from here: http://bit.ly/2vHHqDk
  • glue everything together
  • you are done!