> There is usually the not entirely trivial problem of knowing how to set up the antenna
Although efficient design is important, it's not always the case...
Once, as a kid I lost the antenna to a handheld (military band) radio and couldn't communicate with home base several km away. However, there was a fence nearby with broken wires. Problem solved, communication established. (Yes, I just plugged the one end of the broken fence wire into the antenna socket.)
I'm sure that my worldly and knowledgeable older self wouldn't have even tried it as a solution, assuming it wouldn't work.
You made a "random wire" end fed antenna. Your more knowledgeable older self might not have tried it, but an even more knowledgeable amateur radio operator definitely would have.
As long as you avoid even multiples of half the wavelength you're trying to work, it's an easy way to make a usable antenna.
> I'm sure that my worldly and knowledgeable older self wouldn't have even tried it as a solution, assuming it wouldn't work.
You have to keep reminding your older self that everything that conducts electricity can be used as an antenna in a pinch :). Up to and including your own body, or a stream of salt water squirted from a tube (in fact I recall reading about military testing out such antennas made of sea water on ships).
In a college class we tried using rockets for transmitting.
Like, the middle-school "rocket club" style rockets, a simple kit with a control board, and another that just had a very large spool of wire a la guided anti-tank missiles. They both sorta worked. Had to get clearance from the local airport about it, actually.
Although efficient design is important, it's not always the case...
Once, as a kid I lost the antenna to a handheld (military band) radio and couldn't communicate with home base several km away. However, there was a fence nearby with broken wires. Problem solved, communication established. (Yes, I just plugged the one end of the broken fence wire into the antenna socket.)
I'm sure that my worldly and knowledgeable older self wouldn't have even tried it as a solution, assuming it wouldn't work.