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Don Kimberlin's Notes on Early Radio, The Future of A.M., Questioning Marconi, Remembering ITT, Hearing Spark, A.M. and F.M., Negative and Positive

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Early Radio

Tom:

The photo caption in your telephone history series is, despite it coming directly out of a book, incorrect. The large electronic tube is not the single "500 kilowatt valve."  It was one of FIFTY-FOUR ten kilowatt tubes operable in parallel to form the transmitter at Hillmorton, near Rugby, in England.  When I finish this note, I'll try to find the web link to a local web page from there that has some of the description of the site. That plant exists today and is still on the air, its 8 towers of 800 odd feet being visible for miles around.

The giant transmitter is actually ten radio amplifiers of 100 kilowatts input, 54 kilowatts output each. That, if used together, is called by some one million Watts, based on input; by others, 500 kilowatts or 540 kilowatts based on output. In fact, other than for initial testing, all ten amplifiers were never tied together.  Nine of them are used in parallel, excited from a source of the Very Low Frequency of 16.7 kilohertz. with the callsign GBR - which might stand for Great Britain Radio or Great Britain Rugby, or some ways in England say, "Great Bloody Radio." 

The original purpose of GBR was to be able to send a telegraphic message to anywhere in the old British Empire at any day or time.  It evolved into marine radio use, and since the Cold War, has been used to transmit telegraph to England's nuclear submarines, in the same way the US Navy has several VLF stations for the US subs. The tenth 100 kw in/54 kw out amplifier was the bit used for that first transatlantic radiotelephone link in 1927.  It was excited at 60 kilohertz with a single sideband speech exciter to work with its AT&T mate in the States.  The AT&T reciever ultimately wound up at Houlton, Maine (which was used in later years as AT&T's Telstar satellite station site), and the Deal Beach transmitter on 55 kilohertz was ultimately replaced with one at RCA's huge transmtting plant at Rocky Point, Long Island. The callsign for the British end was GBT, obviously for Great Britain Telephone or such. Speaking of the first transatlantic radio-telephone link, let me mention a few things.

Despite the Bell Laboratories Record account, Deal Beach, New Jersey was merely a Labs testing place, for things like the WWI trials to Europe and such. The actual 55 kHz SSB transmitter for that 1927 London-NY radio link was in the RCA transmitter plant at Rocky Point, way out on the tip of Long Island, 150 miles east of the NYC metro area.

AT&T contracted out the construction and operation of the Rocky Point transmitter throughout its entire life, which was from 1927 until around 1970.

Similarly, I've just received info from some local people in Maine whose knowledge that RCA built a LF receiving station in Maine in WWI (which is probably where Harold Beverage got his start) leads to the likelihood that RCA also built AT&T's receiving station at nearby Houlton, Maine.

In other words the entire US end of the fabled 1927 first transatlantic telephone link was probably built for AT&T by RCA! (After all, AT&T owned 25% of RCA in its early years!). But back to somewhat modern times, at least for a few paragraphs :-) 

When HF (shortwave) radio came into practical use, the VLF link was primarily used as the "backup." Even when the first submarine telephone cable was laid across the Atlantic in 1957, the several shortwave links were retired, but the Rugby-Rocky Point pair were actually kept on the air (but idle) as the final backup - actually in case of nuclear attack that would potentially make render both cables and shortwave useless. It wasn't till there were several cables and satellites in use that the 60 kHz/55 kHz link was retired. In England, the 60 kHz operation's callsign was changed to MSF, and it became England's standard time and frequency reference transmitter, which it is to this day. Over the years, the 1927 transmitters have certainly been replaced, but the British Post Office maintains a security cloak over what the GBR transmitter is today.  They have told that the MSF transmitter has been replaced a couple of times, and we can certainly expect similar change has been made to GBR. Here's the web page, which isn't that well written, for GBR. 

http://62.32.51.17:8033/Radio_masts/  (external link, now having problems)

There's a whole lot more to the early days of telecommunications. I have written a number of vignettes of the monsters of early radio, which I call "Jurassic Telecommunications."  By and large, like the dinosaurs, it grew from cricket chirps into beasts of 100 or even 300 kilowatts, and the final bit were a few megawatt monsters like GBR.    

One of the more interesting ones is the French megawatt spark monster that Blackjack Pershing ordered in WWI, at a Bordeaux location called Croix d'Hins.  It was intended as a backup link across the Atlantic in case the Germans cut the transatlantic telegraph cables. Its callsign was merely LY and operated on VLF of 12.7 kHz.  It didn't last long after the war, because when radio began to develop, it was found to cause so much interference that it had to be abandoned! Here's a page about it:

http://www.u-e-f.net/uef-histoire/croixhins.htm (external link, now dead)

There's a LOT of French history with further links at:

http://www.u-e-f.net/uef-histoire/index.htm (external link, now dead)

And, here are a couple of links about a third monster, Alexanderson's Alternator, of which one plant is still maintained at Grimeton, Sweden, callsign SAQ on 17.2 kHz:

 http://www.telemuseum.se/historia/alex/1.html

 http://www.telemuseum.se/grimeton/defaulte.html  

(Both liinks now dead)

There were (and indeed, still are) many "footprints of the dinosaurs" of radio among us.  Just last month, I was in Florida finding the concrete tower base of the first - ever AM broadcast "directional antenna" in the world. I hope you find all this interesting. I add to the database as I can.  You can see some of it in the Archives section of: http://www.oldradio.com  (external link)

The Future of A.M.

Poor old AM sure took its hits, Tom. But there's a lot afoot these days, First off, the consolidation of ownership has in its way changed many stations from local issue-orientation to regional broadcasters. And, the way telecommunications has become a commodity, we find those regional owners having a set of studios in which programs for a dozen or more stations are generated, I've just been in Tampa, to find a studio center of Clear Channel, one of the largest owners, running nine studios with programs for a dozen stations in and around Tampa and Florida's West Coast, for example.

More recently, on an auto trip from here to Dallas via Atlanta, I noticed several AM's which individually could not cover the Atlanta metroplex, but which carried the same program all day. One pair was even on adjacent channels, 1060 and 1070, so it took but a flick of the dial to continue to hear their program when driving across the entire city, as I did.

And, there's the newly emergent matter of IBOC- In-Band On-Channel digital AM stereo transmission. As with most technologies, there's a American way that's incompatible with the European "world standard" way, but if you heard the results of either, you'd be amazed. There's a website somewhere that I stumbled on that plays audio from both ways, and the digital result is nothing short of amazing! One of the demos is a movement from a full orchestra classical piece, played on a shortwave broadcast station, The analog sample is full of all the noises, fades and distortions of shortwave radio, while the digital rendition is crystal clear the whole time.

Will that save AM? Will satellite-delivered radio kill both AM and FM? Who knows? All I can say is I'm not scrapping my old Hallicrafters just yet. If nothing else, it may become a museum piece! If you'd like to see more about me, see my (out of date) personal website: http://members.fortunecity.com/donkimberlin/ (external link)

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.

Don Kimberlin's Notes on Early Radio, The Future of A.M., Questioning Marconi, Remembering ITT, Hearing Spark, A.M. and F.M., Negative and Positive

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