Frequencies
UK Band Plans

Cables
Standard Wire Gauge
American Wire Gauge

Components
http://toroids.info/
Frank’s electron Tube Data sheets

Equipment
Manuals – KO4BB.com

Computing
Raspberry Pi Wikipedia
PiMyLifeUp

Software
NØ UK’s Maidenhead Grid Distance & Bearing Calculator – An online tool
Online grid square locator and distance/azimuth calculator from Laurent Haas F6FVY