IEEE, ITRE, Memorial University and Amateur Radio Groups
Commemorate the Centenary of Marconi's First Transatlantic Wireless
Experiment
by Joe Craig, Siu O'Young and Len Zedel,
Memorial University, St. John’s, Newfoundland
This article is reproduced in HTML format from the printed version of issue
42 of the IEEE Canadian Review (Fall 2002)
but with the original full size color photographs. The project, reported in
this article, was partially funded as a "Special Grant" by the IEEE
Canadian Foundation.
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1.0 Introduction
On the morning of the centenary day, on the campus of Memorial
University just a few kilometres from where the building
once was where Marconi made history a century earlier,
weak but readable signals in Morse Code were heard on a
radio operated by members of the Marconi Radio Club of
Newfoundland. The signal was greetings from His Excellency Sir Guy
Green, Governor of Tasmania on the opposite side of the world, to His
Honour Dr. Maxwell House, Lt. Governor of Newfoundland, commemorating
the historic day.
Abstract
On 12 December 2001, 100 years after Marconi's first transatlantic
wireless experiment, the IEEE, ITRE (Tasmania) and Memorial
University hosted dignitaries, student competitors in the Marconi
Crystal Radio contest as well as the Poldhu Amateur Radio Club
and the Marconi Radio Club of Newfoundland. Students were
given an opportunity to experience first hand the wonders of radio
communication by designing and building their own radios and
witnessing amateur radio transmissions from around the world.
Marconi's famous experiment was re-enacted by receiving three
sharp clicks from Poldhu on an original Marconi receiver. The
event marked the culmination of two years of planning and collaboration
between many groups. It was an outstanding success in
promoting science, engineering and traditional amateur radio to our
youth and the public, in addition to fostering international goodwill
over the radio.
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Sommaire
Le 12 décembre 2001, 100 ans après la première expérience de
communication sans fil de part et d'autre de l'océan atlantique,
l'IEEE, l'ITRE (Tasmanie) et l'Université Memorial étaient les
hôtes de dignitaires, d'étudiants participant au concours du Marconi
Crystal Radio, du club de radio amateur Poldhu ainsi que du
club de radio Marconi de Terre-Neuve. Les étudiants ont put faire
l'expérience des merveilles des communications radio en concevant
et en construisant leur propre radio en plus d'être les témoins
privilégiés de transmissions provenant des quatre coins du monde.
Entre autres, la célèbre expérience de Marconi fut reproduite par la
réception, sur un récepteur Marconi d'origine, de trois déclics
transmis par les gens de Poldhu. Cet évènement fut le point culminant
de deux ans de planification et de collaboration entre plusieurs
groupes. L'évènement fut un succès retentissant en permettant la
promotion de la science, du génie et de la radio amateur auprès des
jeunes et du public en général, et en encourageant les échanges
internationaux par le biais des ondes radiophoniques.
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Later, following a ceremony at which the young winners of the Marconi
Crystal Radio Contest were announced, a radio message from
Poldhu England relayed greetings to all participants including many
dignitaries and event organisers.
Just after 12:30 local time, a succession of S's transmitted from Poldhu
by Carolyn Rule were heard as clicks on a receiver manufactured by the
company Marconi started himself. This event marked the centenary
with the most authentic re-enactment of Marconi's experiment yet
achieved.
Wednesday 12 December 2001, the centenary of Marconi's first transatlantic
wireless experiment, was marked by a joint effort by the Institute
of Electronics and Electrical Engineers (Newfoundland and Labrador
Section) the ITRE in Tasmania, Memorial University of Newfoundland
and the Poldhu Amateur Radio Club (PARC) and Marconi Radio Club
of Newfoundland (MRCN).
2.0 An early start
Collaboration between these groups when the author, while in conversation
with Mr. Frank Davis, P. Eng, MIEEE early in 2000. Frank
suggested that Mr. Yves Fontaine, P. Eng and chair of the Newfoundland
Section of the IEEE should be contacted so that arrangements
could be made to make the centenary event both productive and memorable.
The event had been commemorated by several amateur radio
organisations for the past four decades, and more recently by re-enacting
a transmission from Poldhu where Marconi's original transmitter
was located using modern equipment. The centenary year we wanted to
re-enact the original experiment in as much detail as possible, bearing in
mind the remark of Mr. Fontaine that we should plan things so that we
had a reasonable chance of success; a caution that was taken very seriously.
Some time later, Mr. Fontaine contacted Prof. Siu O'Young who
would be in charge of the IEEE participation in the event. Following a
meeting between Profs. O'Young and Zedel of the Physics Department
and myself, the idea of a special competition and re-enactment on the
12th of December was conceived. We considered this to be an excellent
opportunity for collaboration for promotion of science, engineering and
Amateur Radio.
3.0 A re-enactment?
It was thought that it might be possible to use apparatus similar to that
used in 1901, but was quickly decided that this was not practical. There
was too much man-made interference to use a crude receiver although
methods of synchronous diode detection was discussed. In addition, a
spark transmission of sufficient power would disrupt existing radio services.
Instead, to preserve some authenticity, several Marconi receivers
were obtained and refurbished, thanks to the assistance of Mr. Barry
Hayes. Mr. Hayes of CMC electronics, formerly the Canadian Marconi
Company, arranged for the supply of surplus equipment and provided
technical expertise. The IEEE assisted in obtaining crystals for the local
oscillators in the superheterodyne receivers.
4.0 Promotion to our youth
The promotional aspect of the event was to be in the form of a receiver
competition for junior high school students. Exposing students in this
age group to radio and electronic principles created a valuable opportunity
to spark their interest in both engineering and amateur radio.
Further meetings centred on defining the parameters of the competition:
no amplification was to be used and they would be judged on merit in
terms of sensitivity and selectivity. The receivers would be built from
inexpensive parts provided by the university students who designed a kit
while working at Dr. O'Young's Instrumentation, Control and Automation
(INCA) Centre at Memorial University under the direction of engineering
student Jeff Newhook.
There was considerable input from traditional radio amateur operators
who were well known for their wealth of experience and expertise especially
as it pertains to designing and building radio apparatus. During
one meeting at the University, we were privileged to have Mr. Davis
P.Eng, VO1HP on the speaker phone to provide some insight into the
design of crystal radios. Every traditional radio amateur has had some
experience with crystal radio design and Frank was no exception. He
highlighted the importance deploying a satisfactory aerial and adequate
grounding.
Figure 1
(Top) Prototype receiver. The aerial is inductively coupled to the first
of three capacitively coupled tuned circuits. The output is taken from
the third stage and detected with a geranium diode in half wave mode.
The meter measures micro-amps and is in series with the headphones.
(Bottom) The Marconi XH-100 superheterodyne receiver used in the
re-enactment.
Click for a larger view
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Using parts from several radio amateurs including Mr. Bob Lewis,
VO1BL, Mr. Jack Norman, VO1JN, Dr. J. Craig VO1FB, and Mr. M.
Mercer VO1FR, a prototype three stage receiver was constructed. The
tank coils were made by winding #26 enamelled wire onto a 35mm film
cannister. The wire was provided by the Physics Department. These
formed a tuned circuit when connected across each of the three ganged
365 pF variable capacitor sections. Interstage coupling was achieved
through 60 pF variable capacitors. These were adjusted for optimal
selectivity and sensitivity as measured on a signal strength meter. This
was a micro-ammeter provided by the late Distinguished Professor
Murray Brooker, an avid promoter of science. The tuning range of the
receiver was about 500 to 2000 kHz. It was noted that about 25 mA of
current could be obtained in the 3rd stage following detection when
tuned to an AM broadcast station about 15 km away when using an
unterminated Beverage aerial 160 metres long. The internal resistance
of the meter was measured at 2.7 kilo ohm so that the corresponding
power was:
P = I2R = (25 * 10-6)2*(2.7 * 103) = 1.7 mW (1)
This signal was clearly audible in high impedance head phones connected
in series with the detector circuit. The contraption was later dubbed
the IEEE receiver and it became symbolic of the collective contributions
to the crystal radio competition project from the Amateur Radio
fraternity. At one point, the INCA laboratory had a box full of wire and
35mm film cannisters, but efforts to emulate the IEEE crystal receiver
were hampered by the formidable challenge of reproducing a triple-ganged
variable capacitor with household items.
5.0 The initial tests
Several meetings followed involving Drs. Zedel, O'Young and myself in
the INCA laboratory and elsewhere in the Engineering building. At one
point we tested wire aerials and some prototype crystal receivers. These
were tried in a lab on the ground floor in the Engineering building. A
wire was strung out the window and over some nearby trees. A ground
connection was made via the mains ground with good results, although a
bit noisy. The IEEE receiver worked better than the other prototypes but
this was no surprise. The others had only one stage and no commercially
manufactured tuning capacitor. With a broadcast station about 1 km away,
it was not difficult to pin the 50 mA meter in the IEEE receiver. Over
the following months, engineering student Jeff Newhook refined the
receiver competition kits. It would include a diode, some wire, a high
impedance earphone and instructions on how to build a tunable receiver
from common house-hold parts. Because many of the communities outside
St. John's were quite far from an AM broadcast station, Dr. O'Young
suggested a small low power transmitter should be made available to test
the receivers for students in these areas. A 1.8 MHz transmitter with an
output of 0.5 watts was brought to the INCA laboratory. This transmitter
had been previously used as a propagation beacon to study the diurnal
variability as a function of distance up to 1200 km. It was a satisfying
moment when the transmitter was switched on and started sending its
identifier in Morse code. As we took turns listening to the headphones
of the IEEE receiver, we could hear he clicks from the transmitter. It
was very reminiscent of the accounts of Marconi as he passed the
ear-phone a century earlier. Unfortunately, this transmitter could not
be duplicated and modulated in the time remaining, but a source of low
power AM transmitter kits was located. These kits were used instead.
Royal Institution, London, England, 13 March 1908
“...My assistants in Poldhu, in Cornwall, had received instructions
to send on and after 11 December, during certain hours
every day, a succession of S's followed by a short message, the
whole to be transmitted, at a certain pre-arranged speed, every
ten minutes, alternating with 5 minutes' rest.
“Owing to the constant variations in the capacity of the aerial
wire in Newfoundland, it was soon discovered that an ordinary
syntonic receiver was not suitable, although, at one time, a number
of doubtful signals were recorded. I therefore tried various
microphonic self-restoring coherers placed either directly in the
aerial or included in the secondary circuit of an oscillation transformer,
the signals being read on a telephone.
“On 12 December [1901] the signals transmitted from Cornwall
were clearly received at the pre-arranged times, in many cases a
succession of S's being heard distinctly although probably in
consequence of the weakness of the signals and the constant
variations in the height of the receiving aerial, no actual message
could be deciphered.
“The following day we were able to confirm the result. The signals
were actually read by myself and by my assistant Mr. G.S.
Kemp.”
- Guglielmo Marconi addressing the Royal Institution, London,
England. Memorial University, St. John's, Newfoundland, 12
December 2001.
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6.0 Final preparation
Towards the end of November, the site for the Marconi Crystal Radio
Contest was chosen. It was decided that the music building at Memorial
University was the best site. It had high ceilings so that the aerials
for the receiver competition could be raised with helium balloons and a
good location for an aerial for the amateur radio transmitter which
would operate on 14 MHz for the contacts with Hobart on the opposite
side of the world, Poldhu and other sites of historic importance in the
Marconi Legacy.
Figure 2
Atop the Music Building at Memorial University.
Behind and to the right of the quarter wave monopole aerial are the
Science, Chemistry-Physics and Engineering Buildings.
Click for a larger view
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The aerial was constructed with the assistance of the Physics Department
machine shop and parts provided by Dr. J. C. Craig, who participated in
the 1961 commemoration and the author's father. We also received help
from the CBC. The aerial comprised telescoping aluminium tubing 3 cm at
base to 1 cm diameter at top and its length was determined from the
standard equation,
l = c/4f = 300 mms-1/(4 * 14MHz) = 5.4m (2)
A theoretical monopole of this length would have an impedance of
Z = 36.5 + j21.25 ohms (3)
The reactance was reduced by shortening the monopole by five percent.
A total of 9 radial wires 5 metres long were used as a ground plane. The
aerial was installed by members of the MRCN and with the assistance
of personnel from the University Works and Mr. J. Foley of the Department
of Physics and Physical Oceanography. Dr. Zedel completed the
wind stress calculations and determined the weight of lead needed at the
base to keep the aerial from toppling in the wind.
Unfortunately, there was some reluctance expressed by the building custodian
to permit drilling a hole for passing the transmission line into the
building. Dr. Zedel suggested that we use a short section of thin line to
pass through the door jamb. This worked to our satisfaction. During
testing, we found that the resonant frequency of the aerial was very
close to the intended operating frequency. To verify that the aerial was
working, two contacts were made with Europe the first using a transmitter
power output of 100 watts, the second with only 1 watt.
The day before the event, Dr. Zedel and Chris Hammond and I did some
final testing and audio tests with connections between the HF transceiver
and PA system in the auditorium. Dr. Zedel also made the
preparations for the exchange of greetings between the Governor or
Tasmania and the Lt. Governor in Newfoundland.
Figure 3
Mr D Colton uses radiotelegraphy to exchange greetings with radio
amateurs in Villa Griffone, Italy where Marconi did his early work. Dr
Zedel establishes an internet contact with Tunisia while Mr Roberts
displays the Canadian Flag for the 'web cam'.
Click for a larger view
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7.0 The Centenary
On the big day, MRCN members gathered on stage and activated the
station. At about 7:00 AM radio contact was established with the
United Kingdom, but there was some apprehension if radio conditions
were satisfactory for a contact with the antipodes. Fortunately,
the pre-arranged Morse code contact was established with
Richard Rogers, VK7RO, who along with the ITRE were participating
in gala event organised by David Edwards in Hobart Tasmania. David
had participated with us on the 12 December Radio Foundation Day
since 1995. The texts to and from the Lt. Governor and the Governor of
Tasmania were sent and received after a few tries: interference was a
problem at times. Following this, contacts were had all over the world
notably with sites of significance to the Marconi legacy. The operators
included Dave Colton, VO1TK and Frank Davis. We also used internet
links to various sites around the globe and sent video images of the
event.
At about 9:00 AM the grade-nine student contestants in the Marconi
Crystal Radio Contest brought their home built radios in to be tested.
Aerials were made available for each by suspending wires with helium
balloons.
Figure 4
Competition room where receivers were judged. Note the helium balloons
supporting the wire aerials aloft.
(Photo: C. Hammond)
Click for a larger view
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After the testing for selectivity and sensitivity, the contestants and
guests were assembled in the auditorium to hear speeches by dignitaries
which included the IEEE Chairman, Mr. Yves Fontaine, MUN president
Dr. Axel Meisen and the Lt. Governor Dr. Maxwell House.
Following His Honour's address, the winners of the competition, Courtney
Barbour, Alex Goncharov and Sarah Watson were announced.
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Figure 5
(above) The winning receiver, skilfully
crafted by Ms Courtney Barbour.
(Photo: C. Hammond)
Click for a larger view
(right) Ms Courtney Barbour
(center) of Leary's
Brook Junior High
School. Seen also in the
photo are Vijay Bhargava
(left) and Wally
Read (right) from IEEE
Canada.
(Photo: C. Hammond)
Click for a larger view
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The spotlight then moved to the MRCN radio station VD1GM on the stage.
Warm greetings on the occasion of the special centenary were transmitted
by John Rule of the Poldhu Amateur Radio Club station GB100GM
from Poldhu, England, the site where Marconi's signal was sent a century
earlier.
Figure 6
Dr. Len Zedel (standing) and Mr. Yves Fontaine listen as Joe
Craig acknowledges official greetings from Poldhu on HF radio.
The equipment in the picture included an online computer, a 100 watt HF
transceiver, a Canadian Marconi XH-100 receiver and a 1 watt home built
transmitter.
(Photo: C. Hammond)
Click for a larger view
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The audio from the radio was fed through the PA system in the auditorium
so all could hear the signals from across the Atlantic ocean. An
hour later, we had the honour of listening to simulated spark transmitter
sounds from the station of distinguished radio scientist Dr. John Belrose,
VE2CV Director of Radio Science at the Communications
Research Centre in Ottawa. We were then joined by Mr. Dave Bouzane
and Mr. Rene Guerrette from Industry Canada and Mr. Jack Harris,
Member of the House of Assembly for Signal Hill-Quidi Vidi. VD1GM
was then called by our long time friend Carolyn Rule, M0ADA from the
Poldhu station GB100GM. Official telegrams were sent from representatives
of the national radio organisation Radio Amateurs of Canada and
a prepared statement from Mr. Norman Doyle, Member of Parliament
for St. John's East was sent to Mr. Andrew George, Member of Parliament
for Cornwall, England. We were very honoured to receive a
transmission recorded by Dr. Zedel of greetings from Lady Mary Holborough,
the Queen's representative and to accept an invitation from
Chairman Rule to formally affiliate PARC and MRCN. Mr. Harris
exchanged greetings with Dennis Casley, who along with Mrs. Rule is a
councillor for Mullion. Mr. Harris received transatlantic congratulations
on the 11th anniversary of his seat in the House of Assembly. Mr.
Bob Lewis VO1BL sent a message to Poldhu announcing that this was
his 70th year as a licensed radio amateur. This was followed by an official
transmission from Mr. Rene Guerrette, District Director of Industry
Canada to Mr. Barry Maxwell, the director of the Radio Communications
Agency in the United Kingdom. Mr. Maxwell was also greeted by
Dr. Eric Gill, professor of Electrical Engineering and authority on radio
propagation and antennas. At this point, MRCN requested that PARC
send a succession of 'S's. Dr. Zedel connected the Marconi Receiver to
the antenna and much to our delight, we heard what would have been
heard 100 years ago from a spark transmitter - a series of three sharp
clicks. We acknowledged to Mrs. Rule the reception of 'S's and that
the re-enactment of the event a century earlier had been a success.
After a happy final exchange, VD1GM signed clear with GB100GM
and continued to make contacts across Canada and the world.
Figure 7
(Left to Right): Mr. Jack Harris, MHA for Signal Hill
Quidi Vidi, Prof. Eric Gill, Mrs. Michelle Craig, VO1RL, Mr.
Dave Bouzane, VO1DU, Radio Inspector, I.C., Mr. Rene Guerrette,
District Director, I.C., Mr. Joe Craig VO1NA, Prof. Len
Zedel, Mr. Bob Lewis, VO1BL.
Missing from Photo: Dr. T. Avery, VE3PPM, Mr. Frank Davis,
VO1HP, Dr. J. Craig VO1FB, Mr. Dave Colton, VO1TK, Mr.
Roy Dodge, VO1XP, Mr. Barry Roberts, Prof. Siu O'Young and
Mr. Nate Penney, VO1NP.
(Photo: Cathy Young)
Click for a larger view
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8.0 Epilogue
In the month that followed during which VD1GM was authorised by
industry Canada to operate as commemorative radio station, contacts
were made by MRCN members in over 100 different countries.
Other Marconi stations such as Villa Griffone Italy, Cape Cod, USA
and Table Head, NS were contacted. Dr. Craig, VO1FB even made
contact with all 6 continents in the span of a few hours. Contacts
were made on 12 bands spanning MF to UHF. On National Engineering
week 2002, the student chapter of the IEEE had a booth set
up in a shopping mall featuring the Receiver Competition. I was
there to represent MRCN and at one point we met one of the winners
in the contest, Alex Goncharov. He seemed quite interested in a
small home built transmitter and indicated he was quite familiar with
the process of accidently frying semiconductors when I explained the
history of the transmitter - a sign of a true analogue electronics
experimenter. He was optimistic about a career in electrical engineering
and a hobby in amateur radio.
The centenary event was an excellent success and achieved what we
had all hoped it would - to bring electrical engineering, science and
amateur radio to the public and in the hands of our youth to carry on
to future generations.
9.0 For Furthur Reading
[1]. “A History Of The Marconi Company”, by W. J.Baker, Methuen
& Co. (1970).
[2]. “My Father, Marconi”, by Degna Marconi, Frederick Muller Limited,
Great Britain, and McGraw-Hill Book Co., USA (1962)
[3]. “Wireless Telegraphy”, Royal Institution Library of Science (1974)
10.0 Web Extras (not in original publication)
[4]. Marcony Calling web site.
[5]. Poldhu Amateur Radion Club GB2GM web site.
[6]. The Historic Poldhu Wireless Station web site.
[7]. Comitato Guglielmo Marconi International web site.
About the authors
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