history 81 osobnosti 35 radio transmitters 32 radio receivers 28 history of science and technology 24 radiocommunications 21 electronic circuits 19 more ... military history 18 electronics 16 aerials 14 wireless communicaation 13 radio communication 13 telegraph 8 transformers 5 computer technology 5 electronic valves 4 signal generators 4 broadband aerials 4 algorithmization 3 electronic elements 3 ferromagnetism 3 impedance 3 wireless broadcasting 3 radio broadcasting 3 telegraph alphabets 3 production 3 development 3 Moon 2 Earth 2 electric current 2 less ...