Radios, how do they work? (2024)
11 comments
·October 23, 2025dd_xplore
immibis
The crystal radios I know don't have crystal oscillators - the word "crystal" refers to the diode.
tiniuclx
I've been studying for my amateur radio license recently, and this article is a great introduction to the basics.
But really, if you want to get your hands dirty with some practical electronics, and also want to be able to communicate without relying much on nearby infrastructure, amateur radio is a great hobby.
hshdhdhehd
Never thought about the AM bandwidth thing before that is interesting and seems obvious now (from Fourier Transform point of view)
drmpeg
Here's a video of AM modulation. SDR transmitter (running GNU Radio) connected to an SDR receiver.
gtsnexp
This reminds me of a beautiful book written by Paul Nahin, 'The Science of Radio'.
tomhow
Previously:
Radios, how do they work? - https://news.ycombinator.com/item?id=39813679 - March 2024 (109 comments)
psyclobe
Cool article; I’m still baffled though.
giuliomagnifico
The article is interesting but some images have Error 400 so I can’t see them.
mrasong
Probably just a network hiccup.
I ran into the same thing earlier, but it worked fine after a couple refreshes.
null
To get an idea about radios, I made a crystal radio when I was in 7th grade, I only had few components. The only component I had difficulty in getting was the crystal oscillator (I was living in a rural town).
It was mind blowing when I first heard the audio through IEMs ! It felt magical that this contraption was working without any battery source.