Electronics

changpuak.ch: Antenna and filter calculators

classeradio.com: Class E AM Transmitter Descriptions, Circuits, Etc.

VK1SV: Class-E for beginners

dmitrynizh.com: Create Spice Models for tubes

b-kainka.de: Electronic projects

funknetzplanung.com: RF-Calculator

VK5DJ: Yagi Calculator (I used it for calculating 13cm and 70cm Band Yagis, works well)

Smith Chart Calculator

DG0SA: Calculate a Collins Filter for impedance matching

Affiliated Link: PCBWay: Cheap PCBs

VK1SV duplexer calculator

Coplanar Waveguide Calculator

Radio & Ham Radio

radiomuseum.org: Radio schematics

radio-workshop.co.uk: Ray's radio workshop (interesting podcasts)

channel292: German Short Wave station

Radio Merlin: UK Short Wave pirate station

Laser Hot Hits: UK Short Wave pirate station

radiosondy.info: Radiosonde tracking

CB-Funk.at: CB-Radio Austria Forum

hamnetdb.net: Useful map for designing PTP radio links

dxmaps.com: Sporadic-E Maps

HB9EYZ: Locator Map, good for distance calculation

Radio Stehwelle: Short radio program on CB, Paket Radio Node

CB-Funk.at: Index of Austrian CB & PMR groups

S-Meter.de: Create a S-meter scale for any radio with nearly any ammeter

Waris: Motorola radio hacks

W8JI: Endfire Broadside and Collinear Antennas (antenna stacking with diagrams)

Mechanical Engineering

Free Gear Generator

Calculate volume of object in FreeCAD

Programming

freeicons.io: Free Icons (also used on egimoto)

MYIP.is: Get your IP and Hostname (useful for detecting Carrier Grade NAT)

unicode.org: Full Emoji List (Essential for writing egimoto.com articles)

Dr. Shubham Dipt: How to create a Systemd service in Linux

Create timers with systemd on Linux

Manuals

Bedienungsanleitung für Signalschaltwerk QHUZ-S1, QHUZ-S2, QHUZ-SWC (SSW1, SSW2)

Miscellaneous

Home Address of Tobias OE3TEC