With the development of the arc converter radio transmitter in 1904, continuous wave ( CW ) modulation began to be used for radiotelegraphy.
22.
Continuous-wave radio was called radiotelegraphy because like the telegraph, it worked by means of a simple switch to transmit Morse code.
23.
Popular modes of operation include voice communication using amplitude modulation ( AM ), and Morse code using continuous wave ( CW ) radiotelegraphy.
24.
Tianjin Coastal Radio also provides public maritime correspondence ( CP ) services in voice telephony, radiotelex and radiotelegraphy to ships within its range.
25.
Radiotelegraphy using Morse code was vital during World War II, especially in carrying messages between the warships and the naval bases of the belligerents.
26.
Even for a powerful commercial AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles,
27.
To receive radiotelegraphy, the feedback was increased until the tube oscillated, then the oscillation frequency was tuned to one side of the transmitted signal.
28.
When the United States entered World War I, private radiotelegraphy stations were prohibited, which put an end to several pioneers'work in this field.
29.
The heterodyne oscillator is the ancestor of the " beat frequency oscillator " ( BFO ) which is used to receive radiotelegraphy in communications receivers today.
30.
When the United States entered World War I, private radiotelegraphy stations were prohibited, which put an end to Murgaa's pioneer work in this field.
