Monday, April 5, 2010

Trash-digging at its finest: A 1:1.1 SWR VHF antenna for 2€

I followed these WA7YFF's instructions to build this fantastic 2m antenna using just a SO-239 panel-mount connector and 5 wire hangers I found in the trash around the neighborhood. I straightened the hangers with a vise, cut them for 144.8 MHz and mounted the radials overlapping with one another as suggested. I attached the radials to the connector with M3 screws and soldered the radiator to the center pin. The antenna looks very sturdy, and it's very easy to match the impedance of the transmitter by just bending the radials somewhere between 30-40 degrees. Click to zoom:


The end result is a great antenna with a 1:1.1 SWR at 5W. I have managed to reach a digipeater that is 36 Km away with my tracker and a SRB MX146 module that produces just 0.5 watts. I am at sea level, so it's not bad at all!

 

2 comments:

  1. Placing an electrically small antenna in a dielectric reduces its resonant ... this relationship by simulating and measuring two electrically small Wavelink Antennas in.

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