The magic of adaptive filters in amateur radio

Examples of a speech signal (top),
a sinusoidal, and noise (bottom)

Radio amateurs have been using adaptive noise reduction and adaptive notch filters for decades. They came with the advent of audio digital signal processing. 

Few however, understand how different they are from ordinary frequency selective filters and for many they appear to do something magic, very different from ordinary filters.

Customize your own list of favorite screens for the Multi-face GPS Clock

Fav 2 subset with 11 entries (Example in text has 9)

The Clock subset menu of the Multi-face GPS Clock gives you a choice already between:

• All, 50 screens
• Fav 1, 34 screens
• Fav 2, 9 screens
• Calendar, 13 screens
• Clocks, 27 screens
• Astro, 17 screens
• Radio, 12 screens