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RADIO "ISLAND" COMES TO
LIFE
Radio "Island" Comes to Life
WABC's
New Transmitter Is Called an Engineering Dream
Built on
a Man-Made Rock in Long Island Sound
This
article appeared in the New York Times on Oct. 12, 1941.
Fifteen
miles northeast of Manhattan a tiny island of steel,
concrete, copper and glass has grown out of the waves of
Long Island Sound. From the midst of this man-made pile of
metal and masonry a 410-foot steel tower projects upward.
Adorning the top is a steel "hat" 85 feet square, wider by
10 feet than the base from which the tower sprouts. Crowning
the hat like a wispy feather is a device resembling the
antenna of a huge insect.
Ships
that pass up and down Long Island Sound on clear days sight
the tower many miles away, farther at night, because of the
winking lamps around the brim.
Next
Saturday, shortly after 10 P. M., at the touch of a
button--"Columbia Island," as it is now called--will spring
into ethereal activity for the first time as the new key
station of the Columbia Broadcasting System--the newest,
perhaps the most revolutionary, broadcasting unit ever
devised.
Salt
water is supposed to be the ideal "earth" medium over which
to project radio waves. Columbia Island, new home of WABC,
is surrounded with it. Large steamers may sail within a few
feet of the strange-looking new outfit; made so, chiefly,
because of a monstrous vertical lattice aerial. Except for
this tower, which might pass for the fighting top of a
battleship, the balance resembles a swanky, streamlined
yacht club with business-like pier and boarding float. Even
the concrete abutment on which the building and mast rest is
streamlined--curved outward like a clipper's bow to toss
high waves back upon themselves.
Everything about the station has been calculated to a
nicety, even to the right-angled kinks deliberately built
into the electrical "pipes" that convey WABC's 50,000 radio
watts from water-cooled tubes to lattice aerial. These kinks
are lightning arresters in disguise. If a bolt strikes the
tower it is expected to leap off the electrical pipe at the
first corner--certainly the second or third--and flash to
earth over spark gaps to the heavy copper roof of the
building and ninety copper cables extending radially outward
into deep water.
The men
who operate the station actually live within a grounded
metal shell, under which are living quarters for engineers,
workshops, electrical units to supply tube voltages, an
auxiliary Diesel-electric generator that roars into use the
instant a fault occurs in under-water electric cables from
shore, and everything else that modern radio engineering can
devise to keep a station on the air in spite of apparatus
failure or fury of elements. If a subsurface cable springs a
leak an internal gas, at high pressure, keeps the water out.
The
radio plant is virtually two in one. Although almost
entirely automatic in operation the eye of an engineer,
sweeping a dozen control-room electrical meters, may detect
failure in any part of the system. By pressing one of a
series of buttons a train of events is started to eliminate
the trouble--perhaps 100 of the plant's 500-odd selective
electrical relays may open or close, cutting in or out of
the circuit as many as half of the station's 500 vacuum
tubes.
From
water-line to tip of vertical lattice "radiator," every
adornment has a purpose at the WABC plant. The wispy,
feather-like object that tops the 410-foot tower--scarcely
visible from below--is a receiving antenna for two microwave
emergency channels between transmitter and studios at 485
Madison Ave., Manhattan. If land circuits from studio to New
Rochelle and under-water path to Columbia Island fail, the
microwave circuit cuts in an instant later and neither
listeners nor engineers may be the wiser. The direct-by-air
link operates on 330 and 335 megacycles (less than a meter)
from a special sending station atop the Manhattan studios.
Because
of the wide frequency difference between the WABC broadcast
channel (880,000 cycles) and the ultra-short-wave link
(330,000,000 cycles), no interference results despite the
fact that incoming studio program waves arrive at Columbia
Island in the midst of powerful 50,000-watt waves leaving
the vertical radiator to serve millions of set-owners.
One of
the features of the 342-ton vertical radiator is the part
that spreads outward at the top like an umbrella. Commonly
referred to as the "hat," this part perches on four large
insulators. When supplied with broadcast power "a little out
of phase" or electrical step with the main tower on which it
rests, the WABC waves in space are made to "hug the earth"
and become more effective in producing strong signals for
receiving sets. Four huge insulators at the base of the main
tower legs support the whole. Each insulator is designed to
carry more than 3,000,000 pounds; the whole tower will perch
upon three legs, if need be, and withstand 120-mile winds.
Supporting the aerial tower are four large steel-concrete
blocks each weighing 2,500 tons--twenty-two feet square.
Outside is a 3,000-ton sea wall and between tower blocks and
sea wall is 8,000 tons of sand and loam fill upon which
grass and shrubs will grow in the Spring.
The magic of the new WABC, however, is not all above the
waterline; drillers were put to work to find a source of
fresh water for drinking purposes and cooling the tubes. It
was struck 910 feet down.
Incidentally, WABC after Saturday will serve a potential
audience of 14,000,000 listeners, according to CBS
engineers. Radio equipment was designed by the Federal
Telegraph Company of Newark, affiliate of the International
Telephone and Telegraph Co. |
