Sunday, December 6, 2015

Some Antenna Measurements

I have been so swamped with work and family things...and some revisiting of old hobbies such as electronics and HAM Radio. So this post has really nothing to do with security, at the moment. I have been playing with some SDR's and researching some techniques and attacks from that standpoint.

Anyway, I'm having some pains with getting one of my quad-band radios to work and decided that I am going to just homebrew a new antenna. Since I needed the measurements, I figured I'd use Excel to handle the math.

The first chart is the measurements (based on the center frequency for each band) for the Driver and Radials for a Ground Plane antenna. I've double-checked most of the math, somewhat randomly, and I'm 99% certain is accurate.

This chart is the measurements for a J-Pole antenna, based again on center frequency for each band. When I have more time I will be updating this with a better explanation and a generic drawing of a J-Pole antenna and how the different A, B, C, D measurements play a role. Suffice to say, the J-Pole antenna looks really cool to me and I think it would be awesome to build!

Unfortunately, I forgot to record where I got the bottom picture from so I'll have to find the appropriate site/person to credit when I get a minute.