Cartoon Antennas

Studying for the General ham license, which is the next step up from the Technician’s license has led to some interesting (and entertaining) “ah-ha” moments for me regarding the design of radio antennas.

Prior to dipping my toes into the ham test question pools, I’d always thought of antennas as passive equipment, responsible for receiving signals only. (Keep in mind I have no prior background in electronics.)

But it transpires that antennas not only receive, they also SEND signals and as a result short mobile antennas like those used for a car rig can develop quite a bit of voltage at the terminal tip when transmitting.

This brings me to the ah-ha moment– those little balls on the end of an antenna tip are called “corona balls” and their PURPOSE is to prevent high voltage discharge from the antenna tip! They are not just decorative!

Who knew, right?

I remember from my childhood, some of the old cartoons having an animated beeping antenna where the corona ball actually lights up. (A corona is a halo of light– or electricity.) And knowing now that the corona ball prevents high voltage from dangerously flying off the tip of an antenna, that cartoon suddenly makes so much more sense.

I love science.