Volume 1
MIL-HDBK-162A
Section
15 December 1965
ITEM NAME: ANTENNA
TYPE: AT-309/GPX, AT-309A/GPX, AT-309B/GPX, AT-309C/GPX
Antenna Impedance (Input and Output): 52 ohms
or tower mounted with a rotating movement pattern.
Horizontal Beam Coverage: 2 deg
Special features: narrow main beamwidth, very low
Vertical Beam Coverage: 10 deg
backlobe, very low sidelobes, wide environmental
Standing Wave Ratio: Under 3.5 db between 1030
operating range, low band pass filter with a 50 db
and 1090 mc, referenced to a 50-ohm
rejection at 1280 through 11,000 mc, combination of
transmission line.
coaxial line and stripline use In antenna feed system,
Wind Load: 1350 lb with 90-miph wind at 15 rpm
and vertical beam width of 52 deg plus or minus 2 deg.
Temperature Range: -55 deg C to plus 85 deg C (67
The AT-309C/GPX is for all weather operation.
deg F to plus 185 deg F)
The main assemblies of the antennas are: right and
left outboard reflector assemblies, right and left inboard
INSTALLATION CONSIDERATIONS
reflector assemblies, right and left outboard box
Siting: The antenna assembly can be installed in
assemblies, and a right and left inboard mounting box
any location where shielding, natural or man-
assembly. Each reflector assembly and mounting box is
made does not prevent radiation to or from the
approximately 7 ft long. Length of the assembled
antenna. In siting consideration must be given
antenna is approximately 28 ft. Antenna input-output
to radio interference from other electronic
impedance is 50 ohms.
equipments.
RELATION TO SIMILAR EQUIPMENT
Mounting: The four antenna reflector sections are
mounted on the three mounting box assemblies.
Antenna AT-309)A is similar to and one way
The mounting box assemblies provide mounting
interchangeable with AT-309, the difference being
pads for attaching the overall assembly atop a
increased power capabilities up to 300 kw. Also AT-309
suitable mast or fixture. Space requirements
is hinged while AT-309A is not hinged. AT-309, 309A is
vary with rotating or fixed operational.
similar to Anttenna AT-295B.
Cabling Requirements:
The type of cable
AT-309C/GPX is electrically interchangeable with AT-
connecting the antenna to the Receiver
309B/GPX; differs in the method of feed.
Transmitter Assembly is dependent upon the
TECHNICAL DESCRIPTION
installation. In all cases 50 ohm transmission
line must be used.
Frequency: 1000 to 1110 mc
Peak Power Output: 300 kw
Related Equipment:
AN/GPX-19, AN/FPS-3,
Duty Cycle: 0.004
AN/FPS-27, AN/FPS-7, AN/FPS-15, AN/FPS-
Filter Characteristics:
19, AN/FPS-30.
1000 to 1110 mc - 0.5 db (max)
S- and X-bands - 50 db attentuation (min,
PRINCIPAL COMPONENTS AND PHYSICAL DATA
COMPONENT
QTY
HEIGHT
WIDTH
DEPTH
UNIT WT.
(Inches)
(Inches)
(Inches)
Antenna Section, right-hand
1
15
84
15
inboard
Antenna Section, right-hand
1
15
84
15
outboard
Antenna Section , left-hand
1
15
84
15
inboard
Antenna Section, left-hand
1
15
84
15
outboard
Mounting Box Assembly,
1
right-hand outboard
Mounting Box Assembly,
1
left-hand outboard
AT-309/GPX: 2
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