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 Built in 1911-12 by the
Telefunken Communications Company of Germany,
the West Sayville facility, north of the
railroad tracks, west of Cherry Avenue became
one of the, if not the most powerful wireless
station of world war 1.
Two major messages were
hustled out of the station in code the first
to waiting submarines at sea that spelled out
the location of the Lusitania and the second
from German Foreign Minister Zimmermann to
Mexico asking that country to attack the
United States and divert them from the
European war. This last, when decoded by the
British and forwarded to President Wilson
brought this country into the war.
The U.S. Navy managed
the station for the remainder of the war and
continued to upgrade the technology until the
Mackay Company leased the property combining
radio with telegraph. When MacKay left for
Brentwood, the CAA took it over and joined
radio and Aeronautics two technologies that
saw a great deal of development on Long
Island.
The CAA, later the
Federal Aviation Administration or FAA
continued to use the stations radio
capabilities until mid 1995 when they
decommissioned it and let it lay dormant,
attacked by vandals. The Friends of Long
Island Wireless History, a newly formed group
of historians, radio technicians and hobbyists
and just plain Long Islanders are working with
the Town of Islip to save, preserve and
develop the site into a wireless museum that
will also reflect the history of the Island
during the years involved.
Technically the museum
will cover Marconi to satellite. It will speak
to the many applicaztions of wireless
technology through the years. The Friends are
establishing a relationship with the
Smithsonian Institution's Electrical
Collections division and other known technical
associations.
The site is eligible for
the National Register and the Friends are also
working with the N.Y. State Department of
Parks, Recreation and Historic Preservation to
nominate it.
The Telefunken
Transmitter at Sayville
One of the most
interesting aspects of the Sayville Telefunken
station was the unique transmitter it
originally contained. Known as a Joly-Arco, or
Telefunken alternator, it used a combination
of rotating and stationary parts to produce
radio waves. Although it had one major
advantage, which we'll get to later,
Telefunken alternators were not commonly used
outside of Germany. Sayville is the only radio
station in the United States known to have had
one.
The earliest radio
transmitters used a spark between two
electrodes to produce signals. You may have
noticed how far- away lightening makes your
radio crackle. Using a small- scale discharge
of energy similarly, spark transmitters
produced crackles in headphones at distant
receivers. Unlike natural lightening, however,
the spark in the transmitter was turned on and
off by a telegrapher's key, making it possible
to communicate by code. Spark transmitters
were relatively simple devices, and they could
be built in any size desired, from
lunchbox-sized portables to massive units that
filled huge buildings. But even after years of
development, it was apparent that they had
some limitations which could not be helped. A
thunderstorm can be heard all over your radio
dial, and spark transmitters were almost as
bad when it came to tuning. Only a few could
operate in a particular area at the same time
without interference. And they did not cover
very much distance for the amount of power
they consumed.
In 1900,
Canadian-American wireless pioneer Reginald
Fessenden realized there was a better way. If
instead of sparking wild bursts of energy into
the air, a way was found to concentrate that
energy into a continuous wave of a single
frequency, a lot of things would improve. Each
station could be assigned its own frequency,
allowing many more of them operate without
getting in each others' way. It would also be
possible to cover greater distances with less
power. But at the turn of the century, the
only known method of producing continuous
radio waves of any strength was with
electromechanical devices known as
alternators.
To digress a bit, the
alternator is the oldest member of the family
of electrical machines, which includes motors
and generators. In its simplest form, an
alternator consists of a magnet, called the
field, and a piece of wire that connects to
the outside world, which is the armature. Any
time a conductor (wire) is in the influence of
a magnetic field that varies in strength, an
electric current is set up in the conductor.
It is not fully known why this is so, but
rather than fret over the lack of an
explanation, practical- minded people simply
put it to use, starting about 140 years ago.
The strength of the
magnetic field can be varied a number of ways.
Relative motion between field and armature,
typically obtained by forming the armature
into a loop and rotating it in the field is
highly effective. The same results are
produced if the armature is held stationary
and the field rotated instead. Most of the
electric power we use at home and work comes
from alternators that are built this way. In
some designs, called inductor alternators,
neither the field nor the armature moves. The
variations in magnetic strength are produced
by moving a piece of magnetic material between
the field and the armature. If something like
iron, which has a much higher permeability
(ability to be magnetized) than air is used,
the magnetic field "induced" in the
armature gets much stronger as the iron is
brought close. The strength of the field can
even be varied by electrical means, with no
moving parts at all, in which case the device
is more properly called a transformer. As we
shall see, all of these techniques were used
in radio alternators.
The voltage at the
output terminals of an alternator has a
frequency which is determined by the design of
the machine and the speed at which it is
operated. In theory, if any alternator is
operated fast enough, its output will be high
enough in frequency to be used directly for
radio. As you might have figured, however, it
isn't so simple in the real world. The parts
of an alternator must be large in order to
handle practical amounts of power. Big parts
cannot be made to rotate fast enough for radio
work; long before the necessary frequencies
are reached, the centrifugal forces become
excessive and wreck the machine.
There are a couple of
ways of getting around this problem. One is to
use an alternator design that inherently
produces high frequencies, such as the
inductor type, and build its power and
frequency capabilities up to the desired
levels. Ernst F.W. Alexanderson, a
Swedish-born electrical engineer who spent his
career at General Electric, developed this
type of machine to its highest state under
contract to Fessenden. Maurice Latour, a noted
French telephone engineer, produced some
inductor alternators for France's wireless
system that were even more powerful than the
largest Alexanderson machines. The
Bethenod-Latour alternators, as they were
known, differed from the GE machines by having
two or three sections ganged together in a row
instead of just one, which allowed for higher
power levels with moving parts of practical
size.
Working in a different
direction, Dr. Rudolf Goldschmidt in Germany
invented a high frequency alternator that made
use of Newton's Law, for every action there is
an equal and opposite reaction, as it applies
to electromechanical devices. In any
alternator, the production of power in the
armature causes double-frequency pulsations in
the field. Pulsations from any source in the
field also interact with the armature, where
under the right conditions, their frequency
can be added to the armature's frequency.
These two effects are usually considered
nuisances, and engineers do their best to get
rid of them. But Dr. Goldschmidt realized that
if an alternator was designed to emphasize
them instead, they could be used to obtain
radio frequencies at commercial power levels
with machinery that operated at perfectly
ordinary, safe speeds.
Typically, the initial
frequency produced by the rotating armature in
a Goldschmidt alternator was 15,000 cycles per
second. A tuning circuit connected to the
armature and carefully set to that frequency
caused that energy to be reflected to the
stationary field 30,000 times per second.
Another tuned circuit connected to the field
and adjusted to 30,000 cycles per second then
built up the energy at that frequency and
re-induced it back into the armature, where
its frequency was added to that of the
armature, bringing it to 45,000 cycles per
second. It was then reflected one last time
back to the field with another 15,000-cycle
increase to 60,000 cycles, at which frequency
it was radiated from the antenna.
Efficiencies of 80% were
claimed for the Goldschmidt machine, and it
could operate with high power at higher
frequencies than most other continuous wave
transmitters then available. It was popular
for a time, mostly in European stations.
However, it could be finicky. If the
adjustments weren't quite right, the various
energies would not be properly absorbed by the
tuning circuits or the antenna. Instead, they
would stay in the machine and cause it to
overheat. Before long the rotor would expand
from the excessive heat and rub on the
stationary frame, bringing the machine to a
grinding halt and necessitating extensive
repairs. Nevertheless, Telefunken installed a
200-kilowatt Goldschmidt alternator at its
station in Tuckerton, New Jersey, which was
the sister of the Sayville station.
Another approach to
producing radio waves with alternators that
operate at reasonable speeds is to connect
them to static frequency converters that
double and quadruple the frequencies to the
desired point. A static frequency converter is
somewhat like an ordinary power transformer,
having no moving parts. It uses a principle
similar to that of the Goldschmidt alternator
to cause its output to "ring" at
double the input frequency. The Telefunken
alternator at Sayville had an initial
frequency of 9,613 cycles. Two static
frequency converters were used to double this
to 19,266 and then 38,452 cycles, which was
the station's transmitting frequency. It had a
power output of 100 kilowatts, quite
substantial for its day.
The Telefunken
alternator did not reach frequencies as high
as the Goldschmidt machine, and its efficiency
was somewhat lower (around 60%) due to power
losses in the static frequency converters. Its
primary advantage was that it was more
tractable than the other systems since the
machine ran at a slow, safe speed and there
were no deliberate reflections of energy
internally that might get out of control and
cause trouble. Slight misadjustments would
injure only the station's performance, not the
equipment.
Shortly before World War
One began in Europe, a new transmitter was
installed at Telefunken's Nauen, Germany
station, which combined a number of these
concepts. Called the Schmidt system, it used a
gigantic low-speed inductor alternator which
operated at 6,000 cycles. Instead of frequency
converters, a carefully designed tuning
network directly resonated the power into the
station's antenna at 24,000 cycles. The
overall efficiency was 66%, and the station
had an output power of 500 KW, making it one
of the most powerful continuous wave stations
in existence at that time. More powerful
continuous wave stations would not be built
until after the war, and then using a
completely different type of transmitter based
on an electrical arc. In the next article,
we'll look at these transmitters in greater
detail, since an arc was what the U.S. Navy
installed at Sayville following the war to
replace the Telefunken alternator.
Christopher Bacon 12
April 1996
The Navy Arc Transmitter
at Sayville
When America entered
World War I in May, 1917, all radio stations
on U.S. soil were seized and shut down by
government order. Faced with an urgent need
for radio equipment that American industry was
not prepared to supply, many smaller stations
were dismantled for parts that could be used
by the armed forces. Several high power ones,
including the Telefunken stations at Sayville
and Tuckerton, New Jersey, were assigned to
the U.S. Navy, which used them for government
business and ship-to-shore communicatio ns.
Records indicate that aside from the
replacement of Telefunken's employees with
Navy personnel, little else changed at the
stations during the war.
Following the armistice
in November, 1918, the government made it
clear that it would not favor a return to the
prewar situation in which wireless in America
had been dominated by foreign companies such
as Marconi and Telefunken. It had recognized
the value of wireless for political and
military purposes, and it decided that the
United States was going to have its own
wireless system. That era was very different
from ours; the role of government had not yet
expanded beyond planning, regulating, and
defense. So as had been the case with
railroads, and the power, telephone, and
telegraph industries, wireless was turned over
to American entrepreneurs who were trusted to
act in the national interest because it
coincided with their own.
With the Navy
facilitating matters, British Marconi was
persuaded to sell its American subsidiary to
investors in the U.S., who then re-established
it as the Radio Corporation of America. In
Telefunken's case, the U.S. and German
governments negotiated a settlement in which
the Sayville and Tuckerton properties were
included in the war reparations paid to
America. Tuckerton was well situated as a
commercial station but was of little use to
the Navy in peacetime, so it was sold to RCA,
which operated it for many years as a back-up
for Radio Central. Sayville was thought to be
good for a ship-to-shore station and for
relaying messages to other Navy bases, so in
1920 it was modernized for those purposes.
A number of buildings
were constructed, including barracks, eating
and recreation facilities, and offices. Some
farming was reintroduced to the land, and with
large fuel storage areas and its own power
plant, the station became capable of
self-sufficiency for weeks at a time if
necessary. A new transmitter building, which
is still standing and is one of the structures
FWHLI hopes to preserve, was built. The
Telefunken equipment was removed and studied,
after which at least some of it reportedly
ended up at the Ford Museum in Dearborn,
Michigan. The original station building was
adapted to house large motor-generator sets
for a new 200-KW arc transmitter, which was
connected to the 500-foot antenna installed by
Telefunken.
The transmitter was
manufactured by the Federal Radio Telegraph
Company of Palo Alto, California (not to be
confused with the Federal Telephone and
Telegraph Company of Buffalo, New York, which
manufactured radio receivers from 1921 until
1929). Considered the birthplace of Silicon
Valley--the company initiated the tradition
later followed by Hewlett Packard and Apple
Computer of starting in a garage, in which Dr.
Lee DeForest performed some of his later
vacuum tube experiments--Federal manufactured
equipm ent for sale and also operated a
network of ship-to-shore stations, most of
which were on the west coast. Ironically,
Federal was later purchased by Mackay Radio,
which in turn leased the Sayville station from
the Navy in the 1930s for use as the
transmitting half of a commercial
ship-to-shore system (Mackay's receiving
station was in Southampton).
Federal's arc
transmitters, developed to compete with the
Alexanderson alternator and its German
cousins, were very unusual devices which made
use of some rather esoteric phenomena.
Pioneering British scientist Sir Humphrey Davy
had discovered in the 1840s that under the
right conditions, when two electrodes are
brought into contact and separated, an
electrical flame or arc develops between them.
Trying different materials, it was found that
carbon rods create a brilliant bluish-white
flame, and by the early 1850s, carbon arc
lamps were in use for street and theatrical
lighting. Households had to wait until Thomas
Edison made incandescent lighting practical,
however; aside from getting extremely hot, arc
lights cause "sunburns" at close
range (the dangers of ultraviolet radiation,
which carbon arcs generate copiously, were not
then understood), they create smoke and odors,
and they hiss and splutter. The carbon rod
electrodes had to be replaced frequently, and
the fixtures were mechanical contraptions that
slowly fed the rods into the arc as they
burned away. Although carbon arc lights are
rarely used nowadays, the principle is still
very much alive for cutting metals and for
industrial furnaces. As an aside, the earliest
high-frequency alternators, discussed in
article #1 of this series, were designed
independently by Nikola Tesla and by J.J.
Thompson in 1890 specifically for arc
lighting. Alternating current has numerous
advantages, particularly for big street
lighting systems, but when conventional AC
power was used, the lamps buzzed loudly. It
was hoped that by using a frequency above the
range of human hearing, AC-powered arcs would
not be so objectionable. While these
experiments only made a marginal impact on arc
lighting, they led almost directly to the
development of alternators for radio use! So
it can be said that the arc gave its chief
rival in wireless a head start, and then set
out to catch up.
The arc entered radio in
1900 when an experimenter named Duddell made a
startling discovery. An arc lamp he connected
to a capacitor started singing! The noises
were caused by the flame blowing out and
re-starting at an audible rate as energy
transferred between it and the capacitor. The
reason why this happens is in the nature of
all arcs, which have the unusual
characteristic of drawing less current as the
voltage across them is increased. This
feature, called "negative
resistance," is still vital in certain
classes of electronic circuits today. If a
power supply is made unstable (i.e. the
voltage changes greatly with load), the
voltage across the arc settles to a level
determined largely by the amount of current
taken by the arc. When the rods are first
brought together, a great deal of current
flows and the voltage is very low. They are
held together until they get red hot, after
which they are separated a small distance.
This "strikes" the arc, or causes it
to start burning. Since the flame does not
conduct electricity so well, the current drops
and the voltage goes up. This causes the arc
to conduct even less current, which in turn
allows the voltage to rise further until the
arc literally blows itself out. When that
happens, there is no longer any load on the
circuit at all, so the voltage assumes the
full level of the power supply, charging the
capacitor along the way. For a brief instant,
the area around the electrodes is still full
of ionized particles from the flame. At
maximum voltage, a spark can jump through
these particles, which re-strikes the arc
without moving the rods. This drags the
voltage down again, but now the energy stored
in the capacitor gets into the picture. It
forces the voltage up, blowing the arc out
again, and the cycle repeats. Depending on how
one goes about it, an arc can be made to
"sing" anywhere from dozens to many
thousands of times a second. Duddell only saw
in his arc a toy or novelty, but others
recognized that if it could be made to sing
its tune at radio instead of audio
frequencies, it could be connected to an
antenna and used as a continuous wave
transmitter.
In 1909, Danish
scientist Vladmir Poulsen announced that he
had found a way to do it. He put a singing arc
inside an extremely powerful magnetic field,
which caused it to blow out hundreds of times
faster. This brought it into the radio
spectrum. The speed at which the arc blew out
and re-started was increased further by using
a hollow copper tube for one of the electrodes
and circulating water through it to keep it
cool. Another major improvement was discovered
by trial and error. It had been noted years
earlier that the electrodes in arc street
lighting fixtures lasted much longer if they
were enclosed in airtight glass containers, so
experiments were tried to see what effect
different gasses had on the operation of
Poulsen's arc. A hydrocarbon atmosphere was
found to be highly beneficial because of all
gasses, hydrogen has the best ability to
conduct heat away from the arc, allowing it to
blow out more easily. The hydrogen came from
kerosene, alcohol, or illuminating gas, slowly
introduced into the arc c hamber where they
decomposed in the intense heat. Despite the
mixture of highly combustible materials and
flame, there was little risk of fire or
explosion while the arc was going because the
arc chambers were airtight. The Poulsen arc
transmitter was ready except for one thing: it
needed a promoter.
As luck would have it,
one arrived literally on the doorstep in the
person of Cyril Elwell, an Australian-born
Stanford graduate engineer who got interested
in radio after some San Francisco-area
investors hired him to investigate a wireless
telephone system they were considering.
Elwell's report was discouraging because the
system lacked a source of continuous wave
radio energy, but he realized that if this
obstacle could be overcome, wireless telephony
would have great possibilities. The radio
frequency alternators of Fessenden/Alexanderson/General
Electric, Telefunken, and already controlled
all the electromechanical possibilities with
patents granted or pending, so when Elwell
read of Poulsen's work, he set off for Denmark
immediately, believing it might be too good to
be true. Upon his arrival, he met the
inventor, saw a demonstration, and on the spot
secured the American rights to the arc
transmitter. With some of Poulsen's
assistants, who emigrated to America to help
Elwell (and who later went on to found the
Magnavox Company), the Poulsen Wireless
Telephone and Telegraph company was
established in 1910. That year it built a few
arc stations which it were integrated into a
working network. In 1911, Elwell and his
investors established Federal Telegraph as an
operating company for tax reasons, and over a
period of time, the Federal name became
predominant.
The fact that the arc
had to re-strike itself in order to work gave
these transmitters some totally unique
characteristics on the air. They could not be
controlled by the telegrapher's key because
even with the fastest operators, the spaces
between the "dits" and "dahs"
were too long. In that time, the ionized
particles would dissipate and the arc would
not re-strike. So it had to be left on all the
time while sending and other means used for
keying. In smaller transmitters, the key
interrupted the antenna circuit. As there
could be a few thousand volts of extremely
nasty radio frequency energy involved, this
was not an entirely safe arrangement. It was
also impractical for the larger units, so the
key was connected to shift the transmitter
between two frequencies spread far enough
apart that only one would be heard at the
receiver. One of these carried the messages in
normal Morse code, and the other was a mirror
image of it. Woeful was the operator thought
he was coping a message in cipher only to find
out he had inadvertently tuned in the
"back wave!"
Originally skeptical,
the U.S. Navy tried arc transmitters in 1911,
and liked them enough to equip many of its
land and larger ship stations with them for
nearly the next 20 years. The transmitters
were compact for their power ratings,
efficient, very simple to operate and
maintain, and could operate over a far wider
range of frequencies than alternators. They
could be made in any size from small portable
units (which were used as signal generators in
labs) to one-megawatt mammoths, designed
towards the cl ose of World War I, which were
the most powerful radio transmitters then
known. Even before the first pair left Palo
Alto for the Lafayette Station being built by
the U.S. Navy near Bordeaux, France, Federal's
chief engineer wrote a memo in which he said
he saw no theoretical reason why even more
powerful units couldn't be built.
Theoretically possible,
maybe, but there were a lot of practical
reasons why bigger arcs were never developed.
Aside from producing back waves, which were a
waste of power and radio spectrum, the signals
were not as clear as the waves from
alternators, and this was a step in the wrong
direction when it came to transmitting voice
and music. (Despite this, huge carbon
microphones were actually used to modulate arc
transmitters for voice and music. Lee DeForest
operated experimental transmitters of this
type in New York City beginning in 1907, and
Charles Herrold built one in San Diego,
California for the first regularly scheduled
radio broadcasting service, in 1911.)
Depending on how heavily they were used, arc
transmitters had to be shut down as often as
several times a day so the carbon electrodes
could be replaced and the soot cleaned out of
the arc chambers. This was could be downright
inconvenient as it meant that the busier a
station was, the sooner it had to go off the
air. There was no rushing the job either; if
the arc chamber was opened too soon after the
power was shut off, any leftover hydrogen gas
would mix with the fresh air and explode
raucously thanks to the internal components,
which would still be red-hot. By 1917,
researchers in France, England, and Germany
had produced a variety of vacuum tube types
which could handle voice and music as easily
as code. Spurred on by the war, AT&T
developed an excellent series of tubes for
radio transmitters and receivers. The vacuum
tube had been invented by Lee DeForest as a
small-scale radio wave detector, but Irving
Langmuir at the General Electric Research
Laboratory was finding ways to get more power
out of them than anybody had previously
thought possible. The handwriting was on the
wall for arcs and alternators. However, unlike
the alternators, one of which managed to
survive in operating condition until 1995,
arcs had all but disappeared by the outbreak
of World War II.
Though not as long-lived
as some other communications technologies, the
arc transmitter left a legacy which still has
a profound impact on science and society. In
1931, Dr. Earnest O. Lawrence at Stanford
University in California needed a huge,
powerful electromagnet for a physics
experiment. Funding to build one from scratch
was proving difficult to find. Lawrence
learned that a pair of one-megawatt arc
transmitters--the sister pair to the ones
installed at Bordeaux--were still sitting
abandoned at the Fe deral plant. The armistice
had put an end to the need for them a dozen
years before. Weighing many tons each, nobody
could think of a use for the huge steel
electromagnetic frames and copper coils, and
the value of scrap metal in the depression had
gotten so low they weren't even worth junking.
When the company heard from Dr. Lawrence, it
was more than happy to donate one of the units
to Elwell's old alma matter. In place of an
arc chamber, Lawrence fitted it with apparatus
that turned it into the world's first working
cyclotron, or atom smasher. Lawrence and his
Stanford lab were "drafted" by the
military and assigned the problem of
uranium-235 production. Another Federal arc
transmitter from the Navy's Arlington station
was similarly converted and used at Columbia
University, where it answered many of the
questions asked by Manhattan Project
scientists during the early development of the
atomic bombs that were dropped on Hiroshima
and Nagasaki.
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