Tag Archives: Historical

The Very First CQ and QSO…

Who called the first CQ and made the first QSO? Who invented AM radio and made the first broadcast? Who did the first 2-way QSO across the Atlantic (Marconi was one way)? …. posted by Layne AE1N.

You All Know Reginald Fessenden. Who?

Quick, name someone influential in the history of radio. Who do did you think of? Marconi? Tesla? Armstrong? Hertz? Perhaps Sarnoff? We bet only a handful would have said Reginald Fessenden. Fessenden was the first man to make a two-way transatlantic radio contact (Marconi’s was one way) and he was a pioneer in using voice over the radio.

He patented transmitting with a continuous wave instead of a spark, which made modern radio practical. This was unpopular at the time because most thought the spark was necessary to generate enough energy.

Start at the Beginning

Reginald Fessenden was born in Quebec in 1866. Eventually, he would move to New York City hoping to work for Thomas Edison.  Once in Edison’s employ, his math skills and troubleshooting skills led to him quickly rising, finally working directly for Edison in New Jersey as a junior technician.

Armed with practical experience, he found several jobs before winding up as a professor at Purdue. There his work came to the attention of George Westinghouse who personally recruited him to be the chair of the electrical engineering department at the Western University of Pennsylvania in Pittsburgh (now the University of Pittsburgh).

Radio Active

About this time, Marconi was in the news for developing a practical wireless transmission system using spark gaps and coherers to send Morse code. Fessenden started experimenting and realized he could do better. By 1899 he had sent messages between Pittsburgh and Allegheny City, using a receiver he designed.

In a talk in 1899, Fessenden showed three different detectors he had been working on. They were sensitive and able to produce a measure of signal strength. He also understood resonance from experiments he’d conducted earlier with multiplex telegraph systems that use various frequencies. This all sounds ordinary today, but remember, Marconi’s system operated at about 8 Hz and the sparks were throwing lots of harmonics and decaying down to zero on each pulse.

Working for the United States Weather Bureau, Fessenden would invent the barretter detector that demodulated radio waves using a hot platinum wire prepared with acid. He followed this up with the popular (at the time) electrolytic detector that used the same kind of wire, but kept it in the acid during operation.

So What?

More sensitive detectors were crucial in making radio more useful. In addition, these detectors could detect amplitude not just on and off like a coherer. Not only did this enable the scientific measurements Fessenden wanted, it also enabled AM radio. By using a carbon microphone in the transmission line, Fessenden was able to successfully transmit voice on Cobb Island in the Potomac River near Washington DC. The distance was only about a mile and the audio quality was not suitable for practical use, but it is considered the first transmission of speech. The message was reportedly: “One, two, three, four. Is it snowing where you are Mr. Thiessen? If it is, telegraph back and let me know.”

Continuous Wave

Fessenden kept experimenting with alternators that would go as high as 50 Hz, but with no amplification, it was difficult to get good results. There were reports that some of the audio tests were even accidentally heard in the Scottish sister station set up by Fessenden’s new company. By 1906 he patented a system for measuring the distance to icebergs using radio waves — similar to modern radar. It was also used during wartime to detect submarines.

That’s Entertainment

Christmas Eve of 1906, Fessenden’s station at Brant Rock, Massachusetts sent CQ using Morse code. Then, he used a microphone to announce the show followed by a gramophone playing Handel’s Largo. He also personally played the violin, rendering O Holy Night. Then he wished his listeners a merry Christmas. Some others were to speak, but they suffered what could be the first case of mic fright, or so it is reported. That was the first entertainment broadcast known to occur. Between connecting radio and telephone, and using broadcasts for entertainment, you can conclude that our inventor had a pretty good crystal ball. He certainly had a big antenna, as you can see.

You can hear a reproduction of the original Christmas program in this video:

Personal

While Fessenden built much of the foundation for radiotelephony, he didn’t have a lot of financial success. The company that sponsored most of his work dismissed him in 1911, leading to a protracted court battle.  The company was eventually sold to RCA who settled the case. He continued to work, but not on the radio. He wound up with over 500 patents. He also became eccentric, causing Radio News, a magazine, to eventually stop carrying his serialized autobiography.

His burial vault bears the words: By his genius, distant lands converse and men sail unafraid upon the deep.

A great sentiment. A shame so few remember him. On the other hand, he did get his own ballad.

Full article: https://hackaday.com/2018/02/19/you-all-know-reginald-fessenden-who/

Posted in Hackaday.