Python Radio 28: It’s Easier than You Think
Understanding how the hardware works.
Programmers are smart people. But sometimes they lack confidence when it comes to hardware issues. Here we will explain how the hardware works and why it works, in a language tailored to programmers. But first, we will build the hardware.
In the previous article, we built a repeater to get more range from our HC-12 transceivers. But we still used the inefficient little spring antennas shipped with the radios.
With those antennas, we can get about 300 meters of range instead of the 1000 meters claimed for the radios. The quarter wave ground plane antenna we built earlier would get the full kilometer (and a bit more).
We chose the ground plane antenna over a dipole because it is easy to adjust the angle of the ground plane wires to 42 degrees to get the 50-ohm impedance match we wanted. But today we are going to build a dipole and match the impedance using a gadget called a gamma match.
For reasons I will explain shortly, we will build our antenna on a sheet of foam-core board 48 inches by 36 inches.
In garden stores, they sell gummed copper tape for keeping snails and slugs away from flower beds. This is very convenient stuff to use when building an antenna on foam core. You can…
