DeFlip Side #166: Fessenden’s Gift

DeFlip Side #166: Fessenden’s Gift.mp3

Welcome everyone. I’m Christopher DeFilippis, and this is DeFlip Side.

It’s Christmas Eve 2015, and all of you who are listening to me on the radio right now are sharing in an experience as old as broadcasting itself. Because it was on December 24, 1906, that the world’s first radio broadcast was made.

On that night, radio pioneer Reginald Fessenden achieved this yuletide milestone from his transmitting station at Brant Rock in Massachusetts. But this was no Christmas miracle; it was a hard-won technological breakthrough that bucked the scientific wisdom of the day and eventually toppled the wireless reign of radio legend Guglielmo Marconi.

But in order to truly appreciate Fessenden’s wireless breakthrough, you need to know a little bit about how radio works. Don’t worry, I’ll make this quick.

Radio waves are basically a byproduct of electricity. Any electric spark emits a radio wave — whether it’s the static electricity that’s discharged when you rub your feet on the carpet and then shock yourself on the doorknob, or the firing of the sparkplugs in your car engine. Marconi figured out a way to transmit radio signals using simple sparks, created by spark gap generators.

Now, what’s a spark gap generator? Think of a more mundane version of the laboratory gadget you see in every old mad scientist movie, where arcs of electricity dance between two poles. Marconi’s machines could manipulate those sparks to transmit electrical pulses, like the dots and dashes of Morse Code.

This ugly buzzing was once the sweet sound of progress, and it enabled radio operators to communicate with each other across continents. But the noisy, sporadic nature of spark gap generators made it impossible for them to transmit true audio.

To transmit something like music or a human voice, you needed a continuous radio wave that could act as a carrier. And that’s where Reginald Fessenden came in.

Fessenden began experimenting with high frequency spark gap generators — which just means that he was trying to figure out ways to produce more sparks closer together. He did something right, because on December 23, 1900, he achieved the first ever audio transmission. His voice traveled for about a mile to a receiving station and was clearly audible amidst the harsh spark gap static.

Fessenden’s next breakthrough was to create a precisely-timed, rotary spark gap transmitter that would generate a series of successive sparks that fired so close together that they would mimic a continuous wave.

Rotary spark gap transmitters were already in use — in fact, that’s the kind of radio the Titanic used to transmit its SOS signal. But Fessenden’s timing improvements led to the first two-way trans-Atlantic radio transmissions of Morse Code signals between Massachusetts and Scotland.

Despite this progress, Fessenden knew that he would have to create a truly continuous wave to transmit real sound. The prevailing scientific belief at the time said that even if a continuous radio wave could be produced, it would never be strong enough to transmit. For that, you still needed the oomph of a spark. So the conventional wisdom went, but Fessenden remained undeterred. And he decided to partner with General Electric in pursuit of his continuous wave. That’s when he began working with Ernst Alexanderson.

Alexanderson was the GE engineer tasked with bringing Fessenden’s ideas to life, and was instrumental in developing a little gadget called an alternator. The alternator used a strong magnetic field to produce an electrical current that alternated at such a high frequency that it was able to produce the pure, continuous radio wave Fessenden had been working for. And so AM radio was born.

On Christmas Eve, 1906, radio operators accustomed to hearing cacophonous spark gap buzzing, were instead treated to a relaxing melody.

And thus had the world’s first radio broadcast commenced, with the soothing sounds of George Fredric Handel reaching ships with Fessenden radio receivers across the North and South Atlantic and as far away as the West Indies.

Fessenden followed this up by playing “O Holy Night” on the violin. He then sung a hymn, and ended with this Bible passage:

“Glory to God in the highest and on Earth, peace to men of good will.”

He encouraged anyone receiving the transmission to send him a letter at Brant Rock; he got mail from 100 miles away. The broadcast had been so successful that Fessenden recreated it a week later on New Year’s Eve.

The ensuing radio revolution didn’t happen over night. In fact, the broadcasts were quickly forgotten as Fessenden went on to develop improvements to radio receivers and tuners. But the genie was out of the bottle and into the aether.

GE ditched all of its spark gap generators in favor if the Alexanderson alternator, which went on to be widely used in Naval and commercial communications. By 1914, even Marconi conceded that Fessenden’s method was superior and purchased licenses to all of his patents.

Fessenden’s breakthrough alternator would eventually be eclipsed by the vacuum tube, but his work, especially in receivers, provided the foundation on which the radio broadcasting industry was built, and his inventions were the basis from which all subsequent advances came.

Of course, more than a century on, most of you hearing this will probably be doing so through an audio stream on a mobile device weeks, months or maybe even years after it was originally broadcast. But for those of you listening to me right now, on the radio, on Christmas Eve 2015, thank you.

Thank you for helping me recreate this grand achievement in wireless. It may not have been a Christmas miracle, but it certainly was a night divine. And in that spirit, I’ll leave now you as Fessenden did, more than 100 years ago.

On Earth, peace to men of good will.

Merry Christmas!