Titanic distress message

[nesesu]

With all the programs on TV this last week or so about the Titanic, I happened to catch a bit of one that started with the distress message from Titanic.
The purported message was in Morse and was a series of 'hissing' pulses on a quite background.
On reflection, I realized that I have no idea what code reception would have sounded like on the Marconi system in April of 1912. Firstly, the detector was, I believe, either a coherier or the Marconi metal tape unit, although on the other ships it may have been a 'crystal' detector. In any case I doubt that you would hear the hiss of the arc of the transmitter, but I don't know what you would hear in the earphones from those various detectors. Also, with the relatively broadband receivers, I would assume the 'atmospherics' would have been substantial, but again, no idea what that would sound like.

Lastly, I seem to recall that in the early days, the code used was not Morse but a special Marconi code.

Anyone on this NG know what reception would have really sounded like on April 15, 1912??

Neil S.

[George Conklin]

"nesesu" <neil_su...@telus.net> wrote in message
news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...

yea

Anyone on this NG know what reception would have really sounded like on
April 15, 1912??

Neil S.

====================

Response:

++
They used spark gap transmitters. They sounded like buzz. One of the
traveling Titantic exibits years ago had a tape recording of exactly what a
spark gap transmitter sounded like....like fast buzz really, rather low in
pitch, quite unlike the sounds generated by a BFO. Not hard to listen to at
all. They did transmit SOS, which was new at the time, as well as the old
distress symbol, which I have forgotten for the moment. And I just threw
out my QST, which had an article on that subject two months ago. I don't
seem to be able to activate QST on line this PM.

[George Conklin]

"nesesu" <neil_su...@telus.net> wrote in message
news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...

==============

Here is a BBC clip. I looked it up through QST.

Wireless operators originally used Marconi's "CQD" distress signal. "CQ" was
the signal to stop transmission and pay attention. The "D" was added to
signal distress. In 1906 the International Radio Telegraphic Convention in
Berlin created the signal "SOS" for summoning assistance. The letters were
chosen for their simplicity in Morse Code - three dots, three dashes and
three dots. While the "SOS" superseded "CQD" in 1908 Marconi operators
rarely used it. It became standard after the sinking of the Titanic.

[George Conklin]

"nesesu" <neil_su...@telus.net> wrote in message
news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...

===============

Here is a link to the last hour or so of the Titanic, with a simulation of
the signals and then translated into words.

http://www.bbc.co.uk/iplayer/console/p00q89fy

Quite sad.

[Richard Knoppow]

"nesesu" <neil_su...@telus.net> wrote in message
news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...

There is a pretty good article on the Titanic's radio
set up at:

http://www.hf.ro/

There is another article at:
http://marconigraph.com/titanic/wireless/mgy_wireless.html


The transmitter was a 5KW rotary arc. Keep in mind
that the transmissions were not continuous waves but
modulated by the arc. The received signal would have had an
audio tone determined by the arc rotation rate probably
around 500 hz.
The receiver on the Titanic was of the Marconi magnetic
type which replaced the coherer used previously on Marconi
ships. The Titanic also had a back-up tube receiver.
The code was "continental" code AKA international code,
the same as is used today. American Morse was used by some
US stations and ships very early on but never on British
ships. The only special code was the U.S. Navy code, also
used only very early on.
The initial distress message carried the Marconi prefix
if CQD, meaning CQ (seek you) distress but after a few
tried the operators switched to the new international
distress signal SOS. SOS has no meaning, it was chosen (by
the Germans BTW) because it is very distinctive ... _ _ _
... The instructions say to exaggerate the dashes.
The first link above has a further link to written
records of the Titanic distress traffic.
Whoever decided on the hissing pulses didn't do their
homework.
There is a very great deal about the Titanic and its
wireless equipment in the literature.


--

--
Richard Knoppow
Los Angeles
WB6KBL
dick...@ix.netcom.com

[Richard Knoppow]

"nesesu" <neil_su...@telus.net> wrote in message
news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...

A century ago it was happening NOW. God Bless all
those who lost their lives and God Bless the survivors
(there are no more) and a moment of silence for remembrance.

[Michael Black]

On Sun, 15 Apr 2012, George Conklin wrote:

> Here is a BBC clip. I looked it up through QST.
>
> Wireless operators originally used Marconi's "CQD" distress signal. "CQ" was
> the signal to stop transmission and pay attention.

Well no. "CQ" is a call to any station. Most traffic is point to point,
so you have the station you are calling. But in an emergency, or in
amateur radio where you just want to talk to anyone, you arent' looking
for anyone specific, you are looking for a response.

Michael

[Michael Black]

On Sun, 15 Apr 2012, Richard Knoppow wrote:


> The initial distress message carried the Marconi prefix
> if CQD, meaning CQ (seek you) distress but after a few
> tried the operators switched to the new international
> distress signal SOS. SOS has no meaning, it was chosen (by
> the Germans BTW) because it is very distinctive ... _ _ _
> ... The instructions say to exaggerate the dashes.

An important consideration is that "SOS" isnt' really. It looks like
the three letters, but is sent as one character, no spacing, so it's
actually a very special character, rather than three letters. It's either
misuse or convenience that it gets called "SOS".


Michael

[George Conklin]

"Richard Knoppow" <dick...@ix.netcom.com> wrote in message
news:RfGdnfvgofzR4BbS...@earthlink.com...

The current issue of the National Geographic contains more information on
the state of the radio room as it exists today. For example, apparently the
switches are still there, and are open.

I have a question. How exactly was the broadcast frequency regulated with a
spark gap transmitter. Since spark gaps create a wide range of frequencies,
how was a 600 meter frequency decided on, and how was the spark gap "tuned"
to that. Was it through the antenna? After all, 500 mHZ is not exactly
what you would call a long-distance frequency today.

Receivers used what to rectify the signal? Crystal sets, I know them. What
did Marconi use?

[William Sommerwerck]

> The transmitter was a 5KW rotary arc. Keep in mind
> that the transmissions were not continuous waves but
> modulated by the arc.

A bit of confusion here. It is not -- strictly speaking -- correct to say
the arc was "modulated". An arc transmitter didn't produce /any/ output
until it was keyed. *

This is why the "modern" system of code transmission is called (very
confusingly) continuous-wave -- CW. The RF is always being generated, with
the key modulating it.

* Mathematically, of course, this /is/ modulation.


> How was the broadcast frequency regulated with a spark gap transmitter?

> Since spark gaps create a wide range of frequencies, how was a 600m

> frequency decided on, and how was the spark gap "tuned" to that?
> Was it through the antenna? After all, 500 mHZ [sic -- MHz] is not exactly

> what you would call a long-distance frequency today.

Your decimal point is off. It's 500kHz, not megahertz.

[Brenda Ann]

"George Conklin" wrote in message
news:lO6dnVN8nd_PkhHS...@earthlink.com...

I have a question. How exactly was the broadcast frequency regulated with a
spark gap transmitter. Since spark gaps create a wide range of frequencies,
how was a 600 meter frequency decided on, and how was the spark gap "tuned"
to that. Was it through the antenna? After all, 500 mHZ is not exactly
what you would call a long-distance frequency today.

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

Tuning the spark wasn't difficult at all. As the spark is much like a square
wave, in that it has many MANY harmonics. The tuned tank simply tuned to use
a specific harmonic (or group of harmonics). It was an energy wasteful way
of doing it, but it worked. Tesla coils work on much the same principle. Not
sure when the transition started, but somewhere along the line land based
transmitters went to using AC generators at the direct carrier frequency
(until the electronic oscillator came into its own).

BTW, it was 500 KHz, which is still to this day used as a marine beacon
frequency (at least on special occasions).

[George Conklin]

"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:jmh3jv$f7t$1...@dont-email.me...

Sorry about the decimal. But how was the frequency limited since spark gaps
cover a huge frequency spread.

[George Conklin]

"Brenda Ann" <newsg...@fullspectrumradio.org> wrote in message
news:2YmdnbL5IMsmiBHS...@giganews.com...

I read that even during World War II very long wave transmitters for
submarines still used AC generators to generate the fundamental frequency.

[Michael Black]

On Mon, 16 Apr 2012, George Conklin wrote:

>
> The current issue of the National Geographic contains more information on
> the state of the radio room as it exists today. For example, apparently the
> switches are still there, and are open.
>
> I have a question. How exactly was the broadcast frequency regulated with a
> spark gap transmitter. Since spark gaps create a wide range of frequencies,
> how was a 600 meter frequency decided on, and how was the spark gap "tuned"
> to that. Was it through the antenna? After all, 500 mHZ is not exactly
> what you would call a long-distance frequency today.
>

It was too early for much regulation. Ship board radio was just really
starting out, one of the first concrete uses for the otherwise lab
curiosity of radio. Maybe it was mandatory at that point for ships to
have radio, but if so it was a relatively new thing.

Spark gap transmitters were relatively broadband. There really wasn't
much control, over the transmitters, frequency, or usage.

It was the Titanic sinking that caused real radio regulations to come into
effect. The Radio Act of 1912 came later that year in the US (and other
coutnries followed), which got those obnoxious amateurs out of the way
(cast out to the useless frequencies above 200metres, about the top of the
current AM braodcast band). The useful frequencies were reserved for
serious use, shipboard radio being the most obvious. Remember, radio
broadcasting didn't arrive until about 1922 (somewhat earlier if you take
someone else's claim)

Michael

[William Sommerwerck]

> Sorry about the decimal. But how was the frequency limited

> since spark gaps cover a huge frequency spread?

That's a different question. I'd like to hear the answer, myself.

[Richard Knoppow]

"William Sommerwerck" <grizzle...@comcast.net> wrote in

message news:jmh708$22m$1...@dont-email.me...

Pretty much only by the selectivity of the tank circuit
and antenna tuner. Its detailed in many places. Many early
arc and spark transmitters could not be keyed on and off,
rather the tuning of the output tank was changed by keying
turns on the coil. This could be done directly (see the
extra large spark keys) or by a relay. One of the great
problems with early wireless was the very broad signals and
that the key-up signal was just shifted over. Eventually, a
single frequency method of keying was developed. According
to Howeth's book, _The History of Communications-Electronics
in the United States Navy_ by a U.S. Navy engineer. This
was called uniwave signaling.
This book is available on-line free and is a great source
of early wireless history.
I am currently reading about five books on the history
of radio, a fascinating mixture of technology, politics,
finance, greed, all the elements of a new industry.

[Richard Knoppow]

"George Conklin" <nilkn...@earthlink.net> wrote in message
news:n8ednY-e5O83ixHS...@earthlink.com...

I think these were holdover Alexanderson alternators.
Some as large as 200,000 watts were built, mostly for
frequencies below about 100 KHz. There is only one left in
existence, in Sweden. Its fired up once a year.
Alternators put out true CW, that is, a single frequency.
They continued to be used after vacuum tube transmitters
supplanted all other types because for the power they put
out they were very satisfactory and replacing them would
have been expensive.
Very low frequencies penetrate sea water and can be
received underwater with relatively short antennas.
Currently, the United States Navy maintains two very high
power transmitters operating in the range between about
10khz and 15 khz for communication with submerged
submarines. Also, these VLF frequencies have the property
of being phase stable so they can be used for extremely
accurate time, frequency, and navigation data.

[Richard Knoppow]

"Michael Black" <et...@ncf.ca> wrote in message
news:Pine.LNX.4.64.12...@darkstar.example.net...

Broadcasting was done experimentally before WW-1 but
the control of all wireless by the government stopped it
until about 1919 when wireless was released again to private
hands. Since there had been great development in practical
vacuum tube transmitters and receivers broadcasting of voice
and music was much more practical following the war. One of
the primary experimenters was Dr. Frank Conrad, of the
Westinghouse company who began fairly regular transmissions
around 1919. By the end of 1920 it became evident that
broadcasting was practical and the United States Department
of Commerce began to issue licenses for commercial
broadcasting stations about the end of 1920. Westinghouse
obtained the first three licenses issued and four of the
first dozen or so. The stations were KDKA, Pittsburgh; WBZ,
Boston; and WJZ, New York. The last was KYA, originally
issued for Chicago but moved later to Philadelphia. All
these were issued in December of 1920. Quite a large number
of licenses were issued in 1921 but 1922 saw an explosion in
stations and home receivers. There is a great deal of
history available both in books and on the web. The early
radio bulletins which list all stations licensed by the U.S.
Government are available at the FCC web site.

[Roger Jones]

On Apr 15, 10:00 pm, "Richard Knoppow" <dickb...@ix.netcom.com> wrote:
> "nesesu" <neil_sutcli...@telus.net> wrote in message
>
> news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...
>

(snip)

>       There is another article at:http://marconigraph.com/titanic/wireless/mgy_wireless.html
>
>      The transmitter was a 5KW rotary arc.  Keep in mind
> that the transmissions were not continuous waves but
> modulated by the arc.  The received signal would have had an
> audio tone determined by the arc rotation rate probably
> around 500 hz.

Sounds about right. I recall from somewhere that it was 300 Hz...
need to check.
Cheers,
Roger

> --
> Richard Knoppow
> Los Angeles
> WB6KBL

> dickb...@ix.netcom.com

[Roger Jones]

On Apr 16, 10:57 am, "Richard Knoppow" <dickb...@ix.netcom.com> wrote:
> "George Conklin" <nilknoc...@earthlink.net> wrote in message
>
> news:n8ednY-e5O83ixHS...@earthlink.com...
>
>
>
>
>
>
>
>
>
> > "Brenda Ann" <newsgro...@fullspectrumradio.org> wrote in

> dickb...@ix.netcom.com

Correct, of course, about rotary generator CW Tx... they came after
Titanic.
The Titanic main Tx was a 5 KW motor generator set producing, IIRC,
300Hz AC to a step up transformer, thence to a synchronized, rotary
spark gap. I presume a crystal or Fleming valve detector would give a
300 Hz keyed tone plus hash to the phones. The transmitted wavelength
was determined by a low-Q antenna tank circuit and antenna
dimensions... given the wide RF band coming off the spark I imagine it
was quite a broad "channel".
BTW, the emergency Tx was a keyed induction coil (the telegraph key
switches, via a relay, the coil "buzzer" contact that runs at natural
frequency to deliver a steam of sparks), the secondary spark went to
the antenna, one one side and ground on the other. Not sure if there
was a tank cct in there. One Marconi Tx used 10 inch coil with, from
memory, around 125 watts of primary power but only a fraction of that
would get radiated as a signal. I've forgotten how big the Titanic
emergency spark coil was... many gaps to fill here, so I defer to
others!
Cheers,
Roger

[dave]

I suspect it would sound like Modulated CW. dits and dahs of pleasant
bass tones. Old Morse had been replaced by International Morse, but is
still Morse.

[Richard Knoppow]

"Roger Jones" <analo...@rogers.com> wrote in message
news:8a69e6a1-5ebb-4b34...@a5g2000vbl.googlegroups.com...

On Apr 15, 10:00 pm, "Richard Knoppow"
<dickb...@ix.netcom.com> wrote:
> "nesesu" <neil_sutcli...@telus.net> wrote in message
>
> news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...
>

There is a great deal of information on early equipment
at:
http://earlyradiohistory.us/
and to other sites he links to. One can also find several
old technical books at:

http://www.tubebooks.org/technical_books_online.htm

The audio modulation of a _rotary arc_ was due to the
periodicty of the rotator. Typically this was some mid audio
frequency, say from 300 to 800 hz. A plain arc was usually
driven by raw AC so its tone was the alternating frequency
of the generator, also generally a mid- frequency tone.
Arc converters, AKA the Poulsen arc, was a CW
transmitter, with no modulation. The Poulsen arc was the
most popular transmitter before vacuum tubes took over. The
Alexanderson alternator was also a CW machine. These were
much larger and more expensive than a Poulsen arc for a
given power.
Arc transmitters can be devided into damped and
undamped arcs. The undamped arc produces CW, an undamped arc
produces a pulsed signal which is very broad band.
Spark transmitters produce damped waves. A number of
variations of spark gaps were used varying from the simplest
to multiple plate gaps to handle very high power. All
depended on the tank circuit and antenna to select the
output frequency and were modulated by the power supply.
One of Marconi's most valuable patents was the "four
sevens" patent (British patent number 7777) for a triple
tuned circuit that had enough selectivity to make these
early transmitters and receivers practical.

The Early Radio site has articles on all of these types
plus a Google search for any of them will find many
articles. I think the Early Radio site has diagrams of arc
and spark transmitters and shows how they were keyed.
All of this stuff was pretty crude.
At the time of the Titanic sinking there was no
official distress frequency, 500Khz came later. Most
maritime communication was in what is now the broadcast band
and down to around 100 khz for long distance work.

--
Richard Knoppow
Los Angeles
WB6KBL

dick...@ix.netcom.com

[Richard Knoppow]

"dave" <da...@dave.dave> wrote in message
news:xbadnbkhp5-rxBHS...@earthlink.com...

Something like MCW but the carrier is either keyed or
shifted. The early keying was a sort of frequency shift
keying with the modulated carrier being present all the
time. Keyed MCW, was used for distress traffic for many
years. The autoalarms made by MacKay Radio were operated by
the modulation while those made by RCA worked on carrier
only. I still remember the local RCA station, KSE, calling
for traffic on 500khz with a modulated transmitter. The
modulation came up slowly, I suspect the filament in the
oscillator warming up. I never had the nerve to try to
arrange a visit. The station was in Torrance with a big
flat top antenna supported by a couple of self-supporting
towers. When I saw it there was a horse grazing there. KSE
was the only station I remember on 500khz with MCW but I
could not hear many.
The autoalarm requried a series of 4 second dashes
separated by one second. Depending on the make it required
either four or five successive dashes in a minute to go off.
Radio room clocks had markings around the second scale for
hand keying the autoalarm signal although the alarm itself
had a clock work keyer. The autoalarm signal would be
followed by the conventional SOS and a message concerning
the nature of the problem and the ship's name and position,
etc.


--

[dave]

I remember the Autoalarm from Radiotelephone Operator exam Element 2.

[bw]

"Richard Knoppow" <dick...@ix.netcom.com> wrote in message

news:Wu-dnXaiEPfRwRHS...@earthlink.com...

Some Poulsen photos here
http://oz6gh.byethost33.com/poulsenarc.htm

[Richard Knoppow]

"bw" <bwe...@hotmail.com> wrote in message
news:jml4p3$r62$1...@dont-email.me...

>
> "Richard Knoppow" <dick...@ix.netcom.com> wrote in
> message
> news:Wu-dnXaiEPfRwRHS...@earthlink.com...
>>
>> "Roger Jones" <analo...@rogers.com> wrote in message
>> news:8a69e6a1-5ebb-4b34...@a5g2000vbl.googlegroups.com...
>> On Apr 15, 10:00 pm, "Richard Knoppow"
>> <dickb...@ix.netcom.com> wrote:
>>> "nesesu" <neil_sutcli...@telus.net> wrote in message
>>>
>>> news:11744688.363.1334517720064.JavaMail.geo-discussion-forums@pbbph3...
>>>
>>
>> There is a great deal of information on early
>> equipment at:
>> http://earlyradiohistory.us/
>> and to other sites he links to. One can also find
>> several old technical books at:
>>
>> http://www.tubebooks.org/technical_books_online.htm
>>
>> The audio modulation of a _rotary arc_ was due to the
>> periodicty of the rotator. Typically this was some mid
>> audio frequency, say from 300 to 800 hz. A plain arc was
>> usually driven by raw AC so its tone was the alternating
>> frequency of the generator, also generally a mid-
>> frequency tone.


>

> Some Poulsen photos here
> http://oz6gh.byethost33.com/poulsenarc.htm
>

Thank you very much for posting this, its a fascinating
site with much good material on it. The home page is
http://oz6gh.byethost33.com/indhold.htm
BTW, I have the 1938 edition of the _Admiralty
Handbook_ and possible an earlier one also.


--

[George Conklin]

"bw" <bwe...@hotmail.com> wrote in message
news:jml4p3$r62$1...@dont-email.me...
>

Wow. We are so used to pocket phones......

[JimCo]

On Apr 18, 4:31 pm, "George Conklin" <nilknoc...@earthlink.net> wrote:
> "bw" <bweg...@hotmail.com> wrote in message
>
> news:jml4p3$r62$1...@dont-email.me...
>
>
>
>
>
>
>
> > "Richard Knoppow" <dickb...@ix.netcom.com> wrote in message
> >news:Wu-dnXaiEPfRwRHS...@earthlink.com...
>
> >> "Roger Jones" <analogd...@rogers.com> wrote in message

> Wow.  We are so used to pocket phones......- Hide quoted text -
>
> - Show quoted text -

This is slightly off topic, but some time ago I read an article in a
reputable scientific journal (I confess I don't recall which one) that
said that Marconi has been mistakenly given credit for being the
father of radio transmission. Presumably Nikola Tesla achieved it
before Marconi did. Just an item of interest.
JimCo

[Michael Black]

On Wed, 18 Apr 2012, JimCo wrote:


> This is slightly off topic, but some time ago I read an article in a
> reputable scientific journal (I confess I don't recall which one) that
> said that Marconi has been mistakenly given credit for being the
> father of radio transmission. Presumably Nikola Tesla achieved it
> before Marconi did. Just an item of interest.
> JimCo
>

Marconi never claimed it.

Radio had been around for a while, I think Hertz (as in MegaHertz). Very
simple and impractical but it showed that a signal could go from point A
to point B without wire.

But it stayed in the lab for some time, just a curiosity.

What Marconi did was prove it as something valuable. In December of 1901,
he showed that radio could span the Atlantic, so it could be used for
distance and thus wasn't just a laboratory curiosity.

Tesla may have had a transmitting device, some of it's vague, Nathan
Stubblefield also put in a claim somewhere.

Marconi was an amateur, he took things commercial be had no education in
the field of electricity or whatever it would have been at the time.

He did commercialize radio, he was setting up radios on ships and if I
recall properly, he owned the equipment and hired the operator (a scheme
not unlike Edison and early electric lighting, especially given there were
no outlets originally).

Once Marconi spanned the Atlantic, it caused more interest in the field.
Military, ships at sea, amateurs. It was a free for all, until the
Titanic proved there was a need for regulation and separate portions of
the spectrum.

Radio was big for a while, apparently newspapers would regularly devote
pages to it, not just news but information like how to build your own
receiver. "Amateur" wasnt' a service yet, it was something you did as a
hobby if you werent' using radio professionally.

Broadcasting did come relativley early, because some were aware that more
people were building receivers than also building transmitters. But it
was amateur to begin with, someone acknowledging those listeners out
there. Reginald Fessenden on Christmas Eve 1906 braodcast voice and
music, which was a neat feat given the available transmitters at the time,
but of course it was still more experimental.

When amateurs became a formal service, I'm pretty sure that took away the
right to broadcast, though perhaps that came later.

And of course, around 1920 or 1922, we saw commercial broadcasting start
up. The Jack Dempsey-Georges Carpentier boxing fight of July 1921 was
actually brodcast, some arrangement being done (I remember an article in
"73" about it, but forget the details).

[Richard Knoppow]

"JimCo" <chem...@ksu.edu> wrote in message
news:5a55403f-52ce-41dd...@p6g2000yqi.googlegroups.com...

On Apr 18, 4:31 pm, "George Conklin"
<nilknoc...@earthlink.net> wrote:
> "bw" <bweg...@hotmail.com> wrote in message
>
> news:jml4p3$r62$1...@dont-email.me...

This is slightly off topic, but some time ago I read an
article in a
reputable scientific journal (I confess I don't recall which
one) that
said that Marconi has been mistakenly given credit for being
the
father of radio transmission. Presumably Nikola Tesla
achieved it
before Marconi did. Just an item of interest.
JimCo

I don't think its off topic at all.
What Marconi did was to combine several previous
discoveries to make a practical system for communication. He
was not the first to demonstrate the transmission of
electromagnetic energy nor to try using it for communication
but he was the first to persist and make a practical system
that could be commercially developed. The early radio site
I cited in an earlier post has some history of Marconi and
his work. Marconi was also an astute businessman, somewhat
unusual for an inventor. Marconi's insistence in
maintaining control over everything he produced eventually
got him into trouble with the United States Navy,
potentially his largest customer.
If you are interested in the beginnings of wireless and
its eventual development into the electronics industry and
broadcasting I suggest the following books:

1. _History of Communications-Electronics in the United
States Navy_ Capt. Linwood S. Howeth USN (Retired)
(Washington DC) 1963 U.S. Government Printing Office LOC
64-62870
This book is available on line free.

2. _Syntony and Spark-- The Origins of Radio_ Hugh
G.J.Aitken (princeton, N.J.) Princeton University Press and
John Wiley & son, 1976 ISBN 0-691-08377-0 Also available as
a paperback.

3. _Wireless: From Marconi's black-box to the audion_
2001, Sungook Hong Massachusetts Instutute of Technology
Press ISBN 978-0-262-09298-3 (hardcover) 978-0-262-51419-4
(paperback)

4. _Inventing American Broadcasting; 1899-1922_ Susan J.
Douglas, (Baltimore) 1989, The Johns Hopkins University
Press ISBN 0-8018-3387-6 (hardback) 0-8018-3832-0
(paperback).

5. _Invention & Innovation in the Radio Industry_ W.Rupert
Maclaurin (New York) 1949, The Macmillan Company
Dr. Maclaurin was director of the industrial relations
department of MIT at the time of writing. It contains a good
discussion of the background of the formation of the RCA.
The book was evidently reprinted in 1971 by Arno Press
but I am unsure if its currently available. A good public
or university library should have it.


These are all well-researched scholarly works but all
are clearly written and easy to read. The last seems not to
be relevant but very much is since it treats on the business
models of early wireless that carried over to the
broadcasting industry in the U.S.
When read as a group they will give you a very good
idea of how wireless started and how the RCA came into
being. RCA was very influential and developed quite
differently from the way is was envisioned by the Navy
personnel who first suggested a way of maintaining American
control of wireless following WW-1 without creating a
government monopoly.

The first book, as stated, is dowloadable from the web
free but hardcover originals are not rare or expensive. The
others must be purchased but are generally available and are
not expensive. Amazon will find all.

I will add to this a book on later development, which
is really an extension of the above.

_Making Silicon Valley: Innovation and the Growth of High
Tech 1930-1970_
Christophe Lecuyer, 2007, The MIT Press ISBN:
13-978-0-262-12281-8 (hard cover)
ISBN-10: 0262-12281-2 (paperback)

[Jim Mueller]

On Wed, 18 Apr 2012 23:12:30 -0400, Michael Black wrote:

> On Wed, 18 Apr 2012, JimCo wrote:
>
>

snip

>
> Radio had been around for a while, I think Hertz (as in MegaHertz).
> Very simple and impractical but it showed that a signal could go from
> point A to point B without wire.
>

> snip

Other people did it before Hertz but they didn't realize what they had
done or couldn't convince others that they had done it. Hertz knew how
to do the math and how to get published in scientific journals so he got
the credit.

--
Jim Mueller wron...@nospam.com

To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.

[Kenneth Scharf]

On 04/15/2012 03:22 PM, nesesu wrote:
> With all the programs on TV this last week or so about the Titanic, I happened to catch a bit of one that started with the distress message from Titanic.
> The purported message was in Morse and was a series of 'hissing' pulses on a quite background.
> On reflection, I realized that I have no idea what code reception would have sounded like on the Marconi system in April of 1912. Firstly, the detector was, I believe, either a coherier or the Marconi metal tape unit, although on the other ships it may have been a 'crystal' detector. In any case I doubt that you would hear the hiss of the arc of the transmitter, but I don't know what you would hear in the earphones from those various detectors. Also, with the relatively broadband receivers, I would assume the 'atmospherics' would have been substantial, but again, no idea what that would sound like.
>
> Lastly, I seem to recall that in the early days, the code used was not Morse but a special Marconi code.
>
> Anyone on this NG know what reception would have really sounded like on April 15, 1912??
>
> Neil S.

The Titanic's radio receiver also had a Fleming valve detector.

[Kenneth Scharf]

The Poulsen arc was actually a form of very high powered tunnel diode.