Category Archives: Antennas

9dB Home brew Collinear Antenna 70cm

Josh, VK2JOS and Sam, VK2AFA

We have slowly been trying to build an Echolink Access point at home to allow us to use Handheld radios in the area (around home, down at the shops etc) without having access issues to the main repeaters due to the lack of output power and antenna efficiency issues that usually come with handheld transceivers.

We decided to build a collinear antenna from plans found online (CLICK HERE) the design seemed fairly simple to construct so we went to work. With both myself and Sam we managed to complete the build within an hour

First issue we had was the length of the antenna at 2m so we decided to build a 70cm antenna until we can get some more material, a 9dB 70cm antenna was just short of 3 meters in length. (as pictured below)

Upon initial testing the antenna proved very impressive, testing from Thornton to Charlestown (approx 25klm as the crow flies) on Simplex against a commercially built 5.5db antenna the results were as follows

Simplex 20 Watts 70cm via 2 x Yaesu 857D Transceivers:

  • Commercial 5.5dB Antenna Signal of S0-1
  • Home Brew Collinear Antenna Signal of S6-7

Both Antenna’s where only mounted 3mtrs above the ground, so it would be expected that even better improvement could be made by mounting it nice and high.