15, December 1965
ITEM NAME: RADAR SET GROUP
icing lamp banks each consist of 21 infra-red, 375 watt
are placed. The platform of the tower is used as a base
lamps. The floors and plat-form of the arctic tower are
for the pressure-supported radome.
designed to withstand a live load of 100 pounds per
square foot. The platform is 20 feet in diameter and the
anemometer, translates wind velocity into dc voltage.
radome is 20 feet high and has a spherical radius of 12-
The various voltages are fed into a sense circuit to
1/2 feet, .
actuate relay controlling radome pressure, so that the
Power Requirements: 120/208v (plus or minus 5v), 60
radome remains firmly inflated and does not dimple -in,
cycle (plus or minus pct), three-phase primary
despite wind velocity increases. Indicator Panel ID-
power through a four-wire" system.
312/FPS-3 located within the operations shelter,
indicates the radome pressure range at any specific
time. Blower blow air into the radome to inflate and
Sitting : In planning the location of the arctic tower site,
Electric Desiccant Dehumidifier HD-
consideration must be given the amount of space
191/GPA-33 removes the moisture from the air of the
available, natural or man-made structures that
radome proper. Interlockingis provided within each
would interfere e with the radar pattern, the slope
radar system, which prevents the antenna from
and type of ground where the tower is to be located,
operating if radome pressure becomes dangerously low.
and layout of existing facilities.
The de-icing lamp banks when focused on the radome
Mounting: Between components, location of the blowers,
interior surface, prevents ice and snow from building up
on the radome exterior. The AN/GPA-33 also has a
relief door is determined by the mounting holes
pressure chamber which prevents loss of radome
provided in the tower structure.
pressure when entry or exit is made.
Location of AN/GPA-33 is
limited by the lengths of the cables to the power
RELATION TO SIMILAR EQUIPMENT
shelter and operation shelter, and the length of the
There also must be 75 feet
minimum separation from the prime radar and
Arctic equipment is designed to keep Radar Set
AN/FPS-4 or Radar Set AN/TPS-1D operable in the
Related Equipments: Radar Set Group AN/GPA-33 is
temperature range of minus 54C (minus 65.2F) to
designed to support and house the antenna and
71C (159.8F), under wind velocities up to 109 knots,
cabinets of either Radar Set AN//TPS-10D
and at altitudes up to 7000 feet. The arctic tower
(AN/FPS-4) or Radar Set AN/TPS-1D.
concrete footing for soil foundations withstand loads
designed specifically for these radars the arctic
footing for soil foundations withstand loads of 4000
tower is capable of accommodating similar radars,
pounds per square foot and 15000 pounds per square
so long as the floor loading limitations and radome
foot. The arctic tower is capable of withstanding two
dimensions are not exceeded.
inches of ice over the radome without exceeding normal
structural safety factors. The anemometer indicates
wind speed through a 0-100 knot range, the double-bed
of water per hour at 24C, inlet air temperature. De-
PRINCIPAL COMPONENTS AND PHYSICAL DATA
Radome Interior Control Group
Indicator Panel ID-312/FPS-3
AN /(GPA-33: 2