[Thursday] When was voice first transmitted over radio?
Ken Carr
kb1awv at yahoo.com
Tue Aug 9 03:04:36 MDT 2022
I am working on it. i gave you the outline.Please do anticipate , compile, and share.
Sent from Yahoo Mail for iPad
On Monday, August 8, 2022, 11:49 PM, Chris Prata <chrisprata at live.com> wrote:
#yiv5276213780 P {margin-top:0;margin-bottom:0;}Maybe we should compile some of the more common visitor questions, and print a few pages of cheat sheets with the answers and leave them stapled together in wireless for those times when we simply forget the info (like I do). Could fit a LOT of these questions in it...
SlavaUkraini!From: Thursday <thursday-bounces at newsm.org> on behalf of Ken Carr via Thursday <thursday at newsm.org>
Sent: Sunday, August 7, 2022 5:31 PM
To: Thursday Group <thursday at newsm.org>
Subject: [Thursday] When was voice first transmitted over radio? That seems like an easy question. One of our museum guests asked me that question some time ago. I told him that one of the first people to do this was a man named Fessenden and he did it in the early 1900’s while everyone else was still trying to improve code transmission with spark gap transmitters. I also noted that the speech in Fessenden’s transmission was mostly unintelligible. I knew there was more to the story. Unfortunately I was not aware of the details.
Wireless Communication in the United States by Thorn L. Mayes fills in many of the details. The book is a publication of NEWSM. Fessenden’s experiment was held on December of 1900 in cooperation with the U.S. Weather Bureau. It was heard for a distance of only one mile and indeed was of poor quality. He used a high frequency vibrator on a spark coil to create the transmission. Apparently it made a modulated buzz. Others tried various modifications of Fessenden’s spark coil voice transmitter but they showed little improvement. Then in 1908 Admiral Evans steamed into San Francisco Bay on the warship Ohio, BB-12. It was known that his ship was outfitted with a de Forest arc set. Numerous amateurs reported that they heard intelligible voice transmissions on their receivers. One way or another this got back to Charles Herrold, the head of a San Jose college for radio operators. By 1909 Herrold, his students, and staff had built an arc transmitter that was modulated by a microphone and produced clear speech! Page 201 of Mayes shows a simplified version of the circuit and page 203 shows the entire apparatus. Read the whole chapter for all the details. The book is available in our bookstore for a mere $5! Hurry and buy one before the museum director catches on! The illustrations in the book are superb.
So, when someone asks “When did transmission of speech over radio begin?”, you will have the answer.As a followup I was able to learn more about the history of the USS Ohio and its Captain Evans. The Ohio was asteamship but when you look at it there seem to be numerous lines to support sails. Actually there seem to be too many lines. I was wondering if they were instead part of an antenna network. Finally I was able to find an a amazing labeled drawing in our national archives. Click on the link and look at item 132A.
And for those volunteers who are forever on a quest to link steam and radio, we may have finally found the golden fleece. Well, at least a few threads.
http://navsource.org/archives/01/010/011060.jpg
Ken Carr
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