747CD Horizontally Polarized Transportable HF Antennas

Type 747CD Series GRANGER™
Horizontally Polarized Transportable HF Antennas
2-30 MHz or 4-30 MHz
Frequency Range with Single
Input
Up to 20 kW Average 40 kW
Peak Power Rating
Horizontal Polarization
Transportable Directional Log
Periodic
2.0:1 Nominal, 2.5:1
Maximum VSWR (2.0 MHz
Version)
Short-, Medium-, and LongRange Communications
General Description
The Type 747CD high performance,
log periodic antenna is lightweight,
transportable, easy to erect and
provides high gain and directivity with
proven reliability. It is designed for
short, medium and long range
communications with a frequency
range of 2 to 30 MHz or 4 to 30 MHz.
One balun transformer is supplied for
the 2 to 30 MHz range. A complete set
of tools and winches, a special
erection fixture and an instruction
manual are also provided with the
system.
Adaptability
For HF communications stations
situated in hurricane and typhoon
zones, the 747CD Series offers quick
restoration of operational antenna
circuits which are damaged by storms.
When such damage occurs, the
antenna can be erected and, with
some advance preparation, made
operational in less than two hours.
The advance work includes selecting a
tower site, burying the guy and
catenary anchors in position and
permanently installing the
transmission line from the
transmitter.
The antennas are easy to erect. The
75ft (22.9m) tower which supports
the antenna is supplied in nested
sections with a special erection fixture
that simplifies installation.
Only two sets of guys are required.
There are no locking latches, sliding
sections or elaborate cable and pulley
arrangements to malfunction; the
design simplicity increases ease of
assembly and reliability.
Transportability
All versions of the 747CD are
sufficiently lightweight to be air
transportable. They can also be
moved from location to another by
truck or other ground vehicle.
Transportable weight and volume of
each version are listed in the shipping
information.
supports each antenna, is fabricated
of 6061-T6 aluminum alloy, a material
extremely resistant to corrosion. The
feedline and radiator assembly,
prefabricated in a single unit, is of
high strength Calsun-bronze wire.
Spacers are of high-purity alumina
ceramic.
The tower has a rigid triangular truss
configuration, with tubular vertical
members that reduce frontal area and
frictional wind drag. It is secured by
two sets of Parafil rope guys attached
to galvanized steel anchors 3.5ft
(1.05m) long.
The antenna elements are made of
materials that resist the effects of
corrosive agents such as salt spray, as
well as ultraviolet light, arcing or
corona.
Strength and Durability
The 747CD Series antennas are built
to withstand harsh environments and
repeated setup and takedown in the
field. The single central tower, which
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Organic plastics, which tend to
carbonize under some of these
conditions, are not used.
Optional 4-30 MHz Compact Antenna
This series is offered as an optional
configuration when available ground
area is limited. Except for operating
frequency, weight and size, the
performance characteristics and
operating features are similar to the
standard series. The frequency range
can be extended from 4-30 MHz to 230 MHz through use of an optional
field conversion kit. An additional
type, 747CD-44, with power ratings of
20 kW average 40 kW peak is available
to meet higher power requirements.
Partial List of Users of 747CD
Horizontally Polarized Transportable
Antennas: U.S. Army, Air Force,
Marine Corps and Navy; Australian
Army and Air Force; U.K. Ministries of
Defense and Aviation; NATO; and the
Canadian and French Governments.
Characteristics
Frequency Range, MHz
Polarization
VSWR without Resistive Loading, max.
Input Impedance, ohms
Gain
Azimuth Plane Half-Power Beamwidth, degrees
2-4 MHz
4-30 MHz
Elevation Plane Pattern
Max. Length of Any Part When Packed, ft (m)
Wind Survival Rating, mph (km/h)
Without Ice
With 0.5 in (12mm) Radial Ice
Erection Time (average ground
Standard Series
2-30
Horizontal
2.0:1 (2.5:1 below 4.2 MHz)
50
See Page 3
Compact Series
4-30
Horizontal
2.0:1
50
See Page 3
Essentially omnidirectional
60
See Page 3
10 (3.0)
60
See Page 3
10 (3.0)
100 (160)
50 (80.5)
2 hours with a 5-man crew
100 (160)
50 (80.5)
2 hours with a 5-man crew
2
Antenna Dimensions
Standard Series 2.0-30 MHz
Compact Series 4.0-30 MHz
Directive Gain vs. Frequency
A ft (m)
317.5 (96.8)
303 (92.4)
B ft (m)
328.3 (100.1)
186 (56.7)
C ft (m)
120 (36.6)
120 (36.6)
D ft (m)
75 (22.9)
75 (22.9)
Elevation Plane Coverage
3
Elevation Plane Radiation Patterns
(Directive Gain in dB Relative to Isotropic)
Ordering Information
Type Number
Frequency Range MHz
747CD-2
747CD-3
747CD-7
747CD-9
747CD-11
747CD-42
747CD-43
747CD-44
747CD-47
747CD-49
2-30
2-30
2-30
2-30
2-30
4-30
4-30
4-30
4-30
4-30
Bulletin 1410B 05/08 Data subject to change without notice.
Power Rating
kW
Average
Receive Only
1
10
2.5
20
Receive Only
1
20
10
2.5
Peak
Input Connector
Female
Receive Only
2
30
30
40
Receive Only
2
40
30
30
Type N
7/8” EIA
1-5/8” EIA
7/8” EIA
1-5/8” EIA
Type N
Type N
1-5/8” EIA
1-5/8” EIA
7/8” EIA
4
ASC Signal Corporation • 606 Beech Street West • Whitby, Ontario, Canada • L1N 5S2 • t. +1 (905) 668 3348 • f. +1 (905) 668 8590 • www.ascsignal.com