Make: Electronics Book - Experiment 28 'Crystal' Radio Set

This is part of a series of videos in which I try out some experiments from 'Make: Electronics', Charles Platt's excellent introduction to electronics.

In this video, Experiment 28 brings the books experiments with inductors to a close by building a 'crystal' radio set.

00:00 - Introduction
01:03 - Why this experiment might not work for you
01:37 - The state of analogue AM radio in the UK
02:02 - How analogue AM radio works
03:35 - Why broadcasters don't transmit audio frequencies directly
06:04 - Sidenote about VLF transmissions
06:42 - How Amplitude Modulation (AM) works
08:22 - Receiver design: the antenna
08:56 - Receiver design: Earth connection
09:38 - Receiver design: the coil (inductor)
10:44 - Where's the capacitor in this LC circuit?
11:19 - Selectivity explained
11:46 - Receiver design: the diode
12:52 - Receiver design: the high-impedance earpiece
13:22 - Outcome of building the radio
14:04 - Sources of AM radio signals in the UK
16:14 - Outro

Links to book:
https://amzn.eu/d/cXyVlfW (UK)
https://a.co/d/i11zkxM (US)

You can find further information on the components used in this experiment in Volumes 1 and 2 of the 'Encyclopedia of Electronic Components':
Vol 1: https://amzn.eu/d/1lzEccv (UK)
https://a.co/d/4S3oVfm (US)
Vol 2: https://amzn.eu/d/4QuPQL9 (UK)
https://a.co/d/5wyCFtg (US)

I'm not associated with, incentivised by, or paid the publisher or author, I'm just a hobbyist sharing my experiences of the book.