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Private Line covers what has occurred, is occurring, and will ocurr in telecommunications. Since communication technology constantly changes, you can expect new content posted regularly.

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Writers

Thomas Farely

Tom has produced privateline.com since 1995. He is now a freelance technology writer who contributes regularly to the site.

His knowledge of telecommunications has served, most notably, the American Heritage Invention and Technology Magazine and The History Channel.
His interview on Alexander Graham Bell will air on the History Channel the end of 2006.

Ken Schmidt

Ken is a licensed attorney who has worked in the tower industry for seven years. He has managed the development of broadcast towers nationwide and developed and built cell towers.

He has been quoted in newspapers and magazines on issues regarding cell towers and has spoke at industry and non-industry conferences on cell tower related issues.

He is recognized as an expert on cell tower leases and due diligence processes for tower acquisitions.

January 03, 2006

Kimberlin questions Marconi, excellent reading ahead

It's accepted that in 1901 Marconi received the first trans-Atlantic radio signal, the letter "S", three clicks, tapped out in Morse code. Don Kimberlin now questions that accomplishment in a well written and researched article, "Investigating Radio's Roots: What Did Marconi Hear? The World's Most Heralded Radio Failure." The article is in .pdf form:
http://www.oldradio.com/archives/jurassic/marconi2.pdf (external link)

Or, if you want the .pdf file from this site click here (internal link)

There's do doubt Marconi's team transmitted a single "S" from Poldhu in Cornwall, near Land's End. But did Marconi actually receive it? Or did he and the sole witness to the event hear something else? Something they mistook for the signal? I've written many times how difficult it is to determine radio firsts; Marconi's claim now proves equally hard to establish. Time to rewrite the history books. Again.

Update. In response to my question to Don, How could an experienced operator like Marconi confuse telegraph dashes for lightning produced static?, Kimberlin responds:

Tom:

How did Marconi might mistake lightning for his desired signals? The key lies in the sound he wanted to hear.

Perhaps I didn't speak enough to the point of the way they had tuned the Poldhu spark transmiter. At the time, their financial strain was such that in order to minimize stress on the Poldhu transmitter, they had reduced the duty cycle of the spark to such a short period that each "key down" on the transmitter produced only a very short "click" of transmission, not the "buzz" we are accustomed to expect from a Type B emission. That way, heating and possible damange while producing maximum power at Poldhu was reduced.

Certainly, Marconi had heard lighting before, but here he was expecting merely a train of 3 clicks in an earphone. They could as easily have come from a natural source as from his transmitter.

I think what is key here is to have some understanding of just how much more favorable a south-north equatorial transmission path is than an east-west one. I may be more sensitive that difference than most people who are not HF propagation specialists, merely because I worked in AT&T's HF radio plant at Fort Lauderdale, FL -- a place that ran largely north-south paths in the equatorial region. It meant we could run commerciallly suitable links most any day of most any part of the solar cycle - high or low - while the AT&T plants at New York and San Francisco often had days of downtime, particularly in lows of the solar cycle.

And, December 12, 1901 was the lowest of low -- a day of absolutely zero sunspots.

Since writing the article, it has crossed my mind there could have been a minor geomagnetic storm, which would be highly unlikely, and I can't rule out one of the annual meteor showers, and I intend to correspond with an expert or two on those. I rather expect their opinion will be neither of those as a cause on 12/12/1901.

March 4, 2004

Tom. Don here again. I have a reader questioning my Marconi article. Let me make a few more comments. People can download the original article in by clicking here. (internal link) Here's what I wrote to that reader:

Thanks for all the complimentary words about my thesis on Marconi. I think it still stands, for these points if not more:

1.) Marconi (and others for more than a century now) with vastly improved technology have never been able to reproduce the experiment. It's a canon rule of The Scientific Method that you must be able to reproduce the experiment for it to stand as accomplished. Think of the more recent "cold fusion" claims that can't be confirmed as an example.

None of that is meant to detract from Marconi and his determination to open a transatlantic (and indeed, if you know about the beginnings of Bolinas, CA) transpacific telegraph business. He proved that by working for four more years, investing huge amounts of money, in which he multiplied his transmitter power by orders of magnitude, lengthened his antennas out to miles and found he had to reduce his frequency right down to 30 kHz or so to establish reliable transoceanic links. Marconi was no piker!

2.) I'm quite familiar with your theory about recognizing the "swing" of an individual telegrapher, having myself worked with the last of the telegraphers in AT&T, TRT, ITT and Western Union's submarine cable system. These people would sit and tap out messages to their comrades wherever they were -- even if it was on a wooden desktop.

In the AT&T locations, we actually had old clickety-clack telegraph sounders, and I could read some of the messages myself. Unfortunately, in that 1901 effort, Fleming was not sending Morse "S" for Marconi to hear, nor even strings of "S." He was sending simply 3 dots at scheduled times. What's more, Alexander Fleming was not a telegrapher. He was a physicist, He had not previously been a regular message telegrapher with Marconi.

3.) The "S" letters we speak of were not a part of message traffic streaming along. It was merely occasional transmissions of 3 dots on a schedule of a few minutes on, then wait a half hour, then a few minutes on and such. And, as you noted, with the short duty cycle they had set on the Poldhu transmitter (fearing they might burn it out), each dot merely sounded like a click. And, I'm sure you have heard static that sounded simply like a "click." That static can propagate around the globe like any RF signal, particularly if it's at HF. And, whatever "key" they had a Poldhu would likely have been a very clunky 1900 style model.

So, here's an added bit to my attempt at slicing this Gordian knot:

a.) Today's antenna analyzers have satisfied themselves that Marconi's Poldhu antenna was a very effective 850 kHz low-pass filter. In other words, no HF got launched from Poldhu on 12/12/1901 when the sunspot count was zero. (BTW, the lowest day of the century!)

b.) Marconi himself reports having at first tried receiving for a couple of days with an antenna tuning arrangement, which was a filter of some sort -likely low-pass.

c.) When he bypassed the tuner, he heard the sort of "signals" he sought, and said that was Poldhu.

d.) But, in removing the filter, he also opened up his receiver to HF, where natural static, in particular from due south of Newfoundland in Amazonian Brazil, one of the earth's three most active lightning sources could skip in to him.

Since nobody knew what "skip" was, nobody at the time would have even thought that Marconi might have heard something else. In fact, the whole notion about "Marconi did it on skip" came from an early 1902 remark by Arthur Kennelly (half of the Kennelly-Heaviside team), who said that barring any other explanation, Marconi might have done it by reflections off some newly discovered ionospheric layers.

In those early days of radio, nobody had means to measure things ionospheric with any accuracy, everyone accepted Kennelly's theory -- and has accepted it without testing since!

I hope that gives you a fair explanation of why I believe Marconi fooled himself, and we have been fooling ourselves since then. As I said, we still owe just about everything we do with radio to Marconi's pioneering, even if he did fool himself.

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