[Contents]
Iconoscope
Chapter
8 - Pre-War World-Wide Television Effort, Zworykin’s European
Travels
1935-1939
The
National Broadcasting Company (NBC), a service of RCA, conducted its
first experimental on-the-air broadcast on July 7, 1930, in New York
City. In that same year, NBC and RCA engineers moved RCA’s
experimental television station W2XBS from Van Cortlandt Park to the New
Amsterdam Theatre Building where they began broadcasting
60-line pictures.
In
June 1931, an RCA-NBC television transmitter was installed on the top
of the Empire State Building and W2XBS began regular television and
facsimile operations in December of that year. Experimental broadcasts
continued and in the next few years, during the course of extensive
field tests, the transmitted picture was increased from 120, to 240,
and then 343 lines, respectively.
NBC,
on June 29, 1936, began field-testing television transmissions from
W2XBS, using Zworykin’s all-electronic television system.
These transmissions were received on experimental receivers scattered
throughout the New York area. In 1937, scanning had reached 441 lines,
and television programming was extended to include pickups remote from
the studio.
Television was officially introduced by David
Sarnoff as a service to the American public on April 20,
1939, at the New York World’s Fair. President Franklin D.
Roosevelt became the first Chief Executive ever to be televised ten
days later.
The
decade of the 1930s also witnessed a rapid growth in interest in
electronic television abroad. Due to the many patent and licensing
agreements RCA had with foreign companies, Zworykin’s Camden
Laboratories became a focal point for many foreign visitors. (p. 101)
This exchange of information on television between RCA and European
laboratories continued throughout the decade, and also partly through
Zworykin’s periodic trips to Europe and his presentation of
scientific papers before various international congresses.
A
person, traveling throughout Europe, before World War II, for the
special purpose of observing television development was, first of all,
greatly impressed by the general interest in the subject not only by
the persons actually engaged in the research and construction of the
equipment, but by the general public as well. In effect, the workers in
the field appeared to be engaged in a strenuous race to see who would
be able to demonstrate the best television picture first. The general
public in turn watched the developments with great interest, this
interest being expressed by the many popular articles in newspapers and
in the semi-technical press and the great attendance at all lectures
given on the subject of television.
After
my trip to Europe in the fall of 1934, I reported that a transition was
taking place from mechanical to electrical methods of picture
transmission. The general impression was that most of the work
in television was directed toward perfecting the electrical methods,
while the mechanical methods were seen only as temporary substitutes or
relics of earlier efforts.
Another
peculiar fact about the European television situation was that in every
country this development was under the auspices of the respective
governments who paid for the erection of transmitting stations, public
demonstrating rooms, programs, etc. In some countries,
particularly in Germany, the government was interested in
television not only as a new method of communication, but also
as a new and more efficient method for propaganda and, more ominously,
perhaps as a new military tool. (p. 102)
In
England, television was largely concentrated in two rival concerns, Electric
and Musical Industries, Ltd. [EMI] and the Baird
Television Company, both of which were building a complete
television system for the Government Post Office. EMI was building a
television system for 240 lines with 25 pictures per second. The
general system was very similar to ours, in fact it was almost an exact
copy. The picture also compared favorably with our own. The Baird
Television Company was building a system of their own using 940 lines
with disc transmitter for film and trying to use a Farnsworth
tube for studio and outdoor pickup. They were building an
entirely separate transmitter and studios. The state of
completion was about the same as that of EMI. The picture shown was
very good considering that it was a 240-line picture.
In
Germany, television research was under the direction of the Government
Post Office. In addition, television was declared a government secret
and some parts of the equipment, for instance, the Iconoscope, were
even considered a military secret. The Post Office kept under strict
surveillance all the developments in the laboratories of several
television firms, the most notable of which were Telefunken,
Fernsehen, Loewe,
and Lorenz. A 180-line picture was provided with a disc transmitter and
cathode-ray receivers. This system was expected to be superseded by a
newer one, which would probably use 375 lines. Telefunken had obtained
a sample of our Iconoscope about a year before and had successfully
reproduced it in their own laboratory. They had a system capable of
transmitting up to 400 lines with a fair degree of deflation.
In
France, the Government Post Office operated a television broadcasting
station in Paris. They were broadcasting a 180-line picture transmitted
by means of a lens disc and reproduced by cathode-ray tubes. The
picture, received over a radio channel, was poor and had a great deal
of interference; difficulties were also encountered with scanning and
synchronizing. A newer system was being constructed in the laboratory
of the Compagnie des Compteurs [in] Montrouge [Paris]. This system used
a disc transmitter for 240 lines and a large radio transmitter. Even
this system was already considered obsolete and the government
was planning a third system with up-to-date equipment and a greater
number of lines to be constructed for the opening of the
International Exhibition that was to be held in Paris in 1937.
In
Holland, television developments were concentrated in the laboratories
of the Philips Company and were mostly for outside sales, since the
Philips Company was a more or less international radio organization.
(p. 103)
The
year 1937 witnessed television development moving almost completely
toward electronic devices. At the receiving end, particularly, this
change was almost universal. With the exception of a few isolated
cases, where a rotating mirror receiver was used in Germany for
demonstration purposes, everyone used cathode-ray tubes for receivers.
It is interesting to note that the European systems universally adopted
high-vacuum cathode-ray receiving tubes, similar to those we used from
the very beginning, instead of the gas filled tubes which they insisted
upon using for so many years.
The
structure of the electron gun, although varying slightly in size and
shape, basically was almost identical to ours. There was a great
variation in the opinion about the best method of deflecting the
cathode-ray beam. Magnetic deflection was adopted by some, while
electrostatic deflection was advocated by others. The general trend was
that where glass-blowing labor was cheaper, electrostatic deflection
was favored. In many cases, thyratrons were used in the deflection
circuits. Most users of the thyratron experienced difficulty in
maintaining adjustment and gradually switched to high-vacuum
devices.
A
large amount of work was being carried on throughout Europe on
fluorescent materials. Special chemical firms concentrated on this
development in practically every country, and every television company
had its own pet fluorescent material which it claimed was better than
all others. The colors were different, ranging from a golden yellow to
practically white.
Three
firms in Europe were successfully manufacturing the Iconoscope. EMI in
England, which started first, was the most advanced. Their Iconoscope,
called "Emitron,"
had several slight modifications from our own model, but these
modifications were not essential and in no way improved the performance
of the tube. Its performance, however, was fairly good and the
sensitivity of their tube was very close to ours.
The
Iconoscopes made by Telefunken and Philips were closely patterned after
the models that we sent to them about a year before. It is of interest
to note that all these laboratories watched our patent applications
very closely and in most cases immediately constructed laboratory
models.
As
far as I was able to discover, the general impression among television
workers in Europe was that the Iconoscope was the only satisfactory
solution to the pickup problem. Those who did not have access to the
Iconoscope and had to use the Farnsworth pickup tube encountered much
difficulty with the transmission of studio and outdoor pictures,
although for film transmission purposes the Farnsworth tube
was usable. (p.104)
A
considerable change in television receivers also was noticed.
Previously, the trend was toward the development of receivers
for one wavelength only, the reason being that only one television
transmitter was likely to be installed in any one large city. For this
reason, most of the receivers were built around the T.R.F.
[tuned radio frequency] system. However, eventually almost
everyone adopted a superheterodyne
method. Our system of transmitting the sound and picture on two
channels with simultaneous tuning for both was practically universally
adopted. There was quite a discrepancy in opinion as to the width of
separation between the picture and sound carrier, the width of the
frequency band for picture transmission, modulation of the picture
signals in the positive or negative direction, etc., but the general
design was more or less the same as ours.
Television
receivers were being prepared not only by firms actually engaged in the
development of television systems, but also by practically every radio
firm. In other words , the moment television broadcasting began, there
immediately appeared on the market a great number of different
television receivers made by various companies.
My
impression of the German government’s particularly strong
interest in television was confirmed by a visit from the director of
one of the big electronic laboratories in Berlin. He came to my hotel
in Budapest, the day after my arrival from Berlin, where I had given a
talk on television to a Radio Engineering Society. He said that "a very
important person" in the government, who was interested in
television, was disappointed that he did not have a chance to
hear my presentation. The professor suggested that I come back to
Berlin and stay there as a guest of the government for a longer time.
He even offered to take me there on a military plane, which he had at
his disposal. This was a flattering proposal, but I had a very
confusing impression from conversations with some of my German friends,
so I declined the invitation. This visibly upset the professor; it
appeared as though he was under orders to bring me to Berlin. When
later in the day I saw Dr. [Eugène] Aisberg, Director of
Tungsram Electronic Laboratory, he congratulated me on my decision and
confirmed my previous impression on the situation in Germany.
I
recollect with great pleasure my visit during the next few days to the
Tungsram Laboratories. It was surprising to me to find in a country as
small as Hungary such a well-equipped laboratory and so much advanced
work in electronics. One of the laboratories which impressed me
particularly was that of Dr. [Paul] Selenyi, who showed me a method of
storing the image on used movie film by electrostatic charging with an
electron beam transmitted by a thin-glass window on a cathode-ray tube.
He was hoping to use this method for a large-screen television
projection picture. As far as I know, he was not able to translate this
idea into practice. However, the idea itself survived and many years
later was used in modern copying machines.(p. 105)
Of
all the trips Vladimir Zworykin made to Europe in the 1930s, his trip
in late 1939 was his most memorable. The trip was organized, as were
all his previous visits, partly for visiting various laboratories, and
partly to attend international conferences in Rome, Zurich, Paris,
London, and Dundee. He sailed from New York to Naples on the Saturnia.
During the crossing, he received a radiogram from the RCA
representative in Tel Aviv requesting him to deliver a talk there on
television.
As
an inducement, he said, he would take me around the country and show me
some archeological points of interest. Accordingly, Mr. A met me in
Alexandria and together we flew to Palestine. After presenting my
report before a very responsive and enthusiastic group of engineers, we
started with A. in his car on a sightseeing tour. At that time
Palestine was still under the British mandate, and it was necessary to
have a special permit to travel through different parts of the country.
For the permit, we had to go to Jerusalem for U.S. and British papers
on account of the unsettled conditions. The most difficult to obtain
was a permit to travel to the Dead Sea, where I was especially
interested in seeing the Solomon
copper mines. For an engineer, I think these mines have
tremendous interest, illustrating how without mechanical power, and
using only prevailing winds, it was possible to build blast furnaces
for smelting copper.
On
our way back through Damascus, I could not resist the temptation to
have a swim, or rather a float, in the Dead Sea.
When
we arrived at the hotel in Damascus, I was handed a telegram from the
American consul telling me to leave the country as soon as I could. It
was obvious that war was imminent and without losing time, we started
for the airport in Beirut. However, many other people had the
same idea and all the departing planes were already booked many days in
advance. Only due to the energy of my companion and by paying a premium
did he succeed in putting me on the plane to Rome. In Rome, the news
was even more alarming; Italy declared mobilization and all
transportation out of the country was canceled. This created a personal
problem for me, particularly since I was scheduled to be in Dundee,
Scotland, in a few days to present my paper. Knowing from past
experience that the most helpful persons in Europe for a traveler are
the concierges in big hotels, I went to talk to one of them. (p. 106)
The
fellow told me that my problem was a very difficult one, but that he
would try to help and suggested that in the meantime I have a good
sleep. About midnight I received a telephone call in my room. Someone
said that he could place me the next morning on the plane to Paris, if
I was willing to pay a premium; of course, I agreed. Next morning I met
the individual who phoned me at a prearranged place in the airport,
which was packed with excited passengers trying to get out of Italy. He
took me behind one of the hangars where there was a plane already
filled with passengers, and in a few minutes we were in the air. A few
hours later, we landed at Le Bourget [airport] in Paris.
Here,
although the excitement was not as intense as in Rome, normal passage
was still not available, but again, by the same method as before, I
succeeded in flying that same evening to London.
The
people whom I visited the next day in London were rather skeptical of
the imminence of the war. They stressed that the Italian mobilization
had already been canceled, and they were confident that there would not
be any war.
So
a few days later, I departed to Dundee and found the Congress was
proceeding as scheduled; my paper on the "Electron Microscope" was on
the program for the next day. The presentation was the last one of the
morning session and during lunch we heard by radio the announcement of
the declaration of war against Germany and mobilization. Of course all
the rest of the meetings were canceled and everyone started home. The
organization committee announced that they had succeeded in securing
accommodations for all participants who wished to go to the U.S.A. on
the S.S. Athenia sailing from Liverpool the next
day.
This
created a small problem for me because most of my luggage had been left
with American Express in Damascus to be delivered to London. To travel
on a ship, and particularly an English ship, without dinner
clothes, according to my past experience, seemed inopportune so I
decided to return to London first and try my luck from there. This
proved to be difficult since the rush of returning Americans already
had started and all accommodations were booked. So I was marooned for a
while in London which now was a completely different city from the one
I left only four days before. It was very interesting to watch how
people adjusted themselves to the new situation. There were many more
pedestrians on the streets than a few days ago. Everyone was carrying a
gas mask, and when I went out without one I was stopped by a policeman
who asked why I did not have one on my person. lie sent me to a place
where he said they would give me one. There, however, I was told that
they did not have masks for tourists. (p. 107)
The
next day I read in the newspaper that the Athenia
had been torpedoed; there was considerable loss of life and injury. I
was so glad that I had not taken it.
To
sit quietly in an atmosphere of general excitement and feverish
activity was impossible for me, so I sent a cable to D[avid] Sarnoff
asking for permission to discuss with British military officials some
of the military work we were doing in our laboratory. I was
particularly anxious to discuss our work on flying bombs with
television sights and methods of measuring distance by means of
ultra-short radio pulses. The permission was promptly granted and our
representative, M. G., arranged an interview with Dr. Darwin, Chairman
of the National Research Council, and two military men from the Navy
and Army.
The
result of this interview was quite unexpected. After I finished my
presentation, Dr. Darwin told me that his country was already at war
and they did not have time to embark on such obvious long-term research
so the best I could do was to go back to my laboratory. I told them
that I had tried to do this but found it impossible and that I
hated to be idle at such a time. The answer was that they would do
something about my passage and the next day I got a berth on the Acquitania
to New York.
A
couple of years later when Dr. Darwin came to the U.S.A. and visited
our laboratory, I asked him why they were so disinterested in my
proposal when I knew by that time that they were engaged and at full
speed in both projects. He answered that they could not discuss them
with me because both of those projects were "top secret." (p. 108)
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