Interesting thoughts on Communication/Ham Radio

 Simple online impedance calculator

 Wellenwiderstand von Zweidrahtleitungen 
VOACAP Online DR2W - Propagation chart Ausbreitung Earth View QRZCQ - Custom Maps Web-SDR QRP Portal AC6V's Amateur Radio And DX Reference Guide Amateur Radio Station M0WYM QSL-Shop UX5UO print QSLs Marconi: Salvan, die Wiege der Telekommunikation