I recently had the need to track the arrival of a flight into the airport near my house. Of course, I could use any of the online services available for this, but being a HAM radio operator, I wanted to track this data myself. I discovered that with a $30 RTL-SDR dongle, this can easily be done.
First, I built a co-linear antenna for this. This is a simple antenna made by connecting stub pieces of coax together. I opted for a 4 element co-linear which is not the best configuration. I will at some time build an 8 element and place it within a PVC pipe. This is just a proof of concept.
Using the plans here https://www.balarad.net/ I made a 4 element antenna.
