Fessenden's First Voice Transmission:
"In the growth of radio it appears that voice transmission was not proposed until Professor Fessenden in l9O2 suggested that his continuous-wave method of transmission was suitable for radio-telephony. There seems to be some evidence that Fessenden made practical trials of speaking radio even before this date.........." John V. L. Hogan, The Outline of Radio, 1922
| For telephony Fessenden's first attempts
to transmit voice employed a spark transmitter operating at something like
10,000 sparks/second. To 'modulate' his transmitter he inserted a carbon
microphone in series with the antenna lead.... He experienced
great difficulty in achieving intelligible sound.
...let us hear how this telephony transmission employing spark might have sounded like.
On the 23 December 1900, Fessenden, after many unsuccessful tries, transmitted words without wires. The speech you hear is the voice of the author, using the transmitter as described above (the best transmission out of several recorded), but the words are those used by Fessenden the inventor.
Click and Listen to Fessenden saying: (296kb .AIF voice file)
"Hello test, one, two, three, four. If it's snowing where you are, Mr. Thiessen. If it is, telegraph back and let me know."
Mr Thiessen telegraphed back immediately. It was indeed snowing where he was. After all Mr Thiessen and Professor Fessenden were only 1 mile apart. But not withstanding, the short distance, and the poor quality of the transmission, this date heralded the beginning of radio telephony.
Edited by John Dilks, K2TQN