Similar keys are used for all forms of manual telegraphy, such as in electrical telegraph and radio telegraphy.

Radiotelephony by 1920s began to displace radio telegraphy for many applications and was the basis of public broadcasting.

Only the emerging field of radio telegraphy saved it - antennas mounted on the tower proved vital to French transmissions.

However, as radio telegraphy and telephony were developed, the use of pigeons became limited to fortress warfare as early as in the 1910s.

Other keying methods are available in radio telegraphy, such as frequency shift keying.

This technique is still used in radio telegraphy, the local oscillator now being called the beat frequency oscillator or BFO.

Early radio transmitters could not be modulated to transmit speech, and so CW radio telegraphy was the only form of communication available.

Early radio telegraphy used spark gap and arc transmitters as well as high-frequency alternators running at radio frequencies.

His field of interest was: antenna design, amplification and detection advanced the development of radio telegraphy.

The licence allows a user to make radio telegraphy and radio telephony transmission in 14 frequency bands.