Early radio receivers worked on a principle called Tuned ... Which is why this study of the simple Superheterodyne shortwave receiver deserves closer study.

Crystal radios may be the simplest kind to make, but regenerative receivers are more practical and only a little more complicated. A recent design by [Selenium] is super simple because it uses a ...

For purposes of this chapter VLF represents the 5- to 100-kHz region. The reason for this seemingly arbitrary designation is that many ham-band and SWL communications receivers operate down to 100 kHz ...