Monday, December 25, 2017

Biquad WiFi Antenna

I have been having a hard time connecting to the free WiFi here in the marina. I have a Bullet-HP with an 8-DB vertical antenna mounted to the mizzen mast. It turns out it is blocked from the office by the mast. Being too lazy to climb up and change something, I did this.

Homemade biquad WiFi antenna

I have a spare Bullet, in case of failure, so I got it out. I didn't have an antenna for it. A directional antenna would be good since I am tied to the dock in the marina and don't move much. The Omni vertical is good for swinging around the anchor because it doesn't get blocked for very long.

I found plans for the biquad on-line. I used a square of single sided PCB (123 x 123 mm) and a spare "N bulkhead" connector that matched the Bullet. I didn't have any 12 gauge solid wire to strip, but did find a piece of 2mm brass rod. I bent it into the biquad shape, two 30.1mm squares. Then I soldered it 15.5 mm above the copper side of the PCB, one center corner to the center conductor of the N connector, the other to ground.

Now I can aim it at the office door and I get a reasonable connection.

I am having a lot of dropped packets when I ping the office router, but I don't think it is the antenna. Seems more like a problem in the office. I don't speak enough Chinese (only 3 words) to ask them to look into it.