747FCD Horizontally Polarized Fixed HF Antennas

Type 747FCD Series GRANGER™
Horizontally Polarized Fixed HF Antenna
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 747FCD Antenna Series intended
for fixed station applications is based
on the single mast, transportable
747CD Log Periodic Antenna Series.
However, materials and construction
techniques appropriate to a
permanent installation are adopted.
The result is an economic antenna
permitting simple assembly and
erection procedures with a single 75ft
(23m) mast, saving on foundation
work.
The variable take-off angle array
configuration results in a high
performance antenna well suited to
applications where communication
over varying distances is required.
Elevation angles are appropriate to
the frequencies commonly used for
short, medium and long distances.
Frequency ranges of 2.0-30 MHz or
the more compact 4.0-30 MHz version
allow a choice depending upon
available site space or distance of
communication.
Power ratings of up to 20 kW average,
40kW peak are available. A single
balun transformer converts the 200
ohm antenna feedline to a 50 ohm
coaxial input.
Strength and Durability
The 747FCD Series Antennas are built
to withstand harsh environments. The
triangular, 17 in face width, guyed
tower is lattice construction with
tubular crossmembers. The corner
rails are of high yield steel and all
parts are hot dip galvanized for
corrosion resistance. The “knockdown” tower is easily bolted together
on site. Guys of extra high strength
galvanized steel wire rope are
attached to the steel hairpin anchors
supplied for installation in concrete.
The feedline and radiating curtain are
accurately prefabricated from
Alumoweld wire, a material extremely
resistant to corrosion, ensuring high
electrical conductivity. The high purity
Alumina Ceramic feedline spacers and
insulators are unaffected by arcing or
corona, unlike organic materials which
tend to carbonize under these
conditions.
Array support catenaries are
fabricated from Parafil, a stable
prestretched parallel filament
dielectric material, surrounded by a
flexible dense black protective sheath
which resists ultraviolet light
deterioration and moisture
penetration.
1
Accessories
The following accessories are available
for ease of installation and
maintenance: tower lighting kit,
erection kit, paint kit, tool kit,
lightning rod kit, anti-climbing kit, and
spares kit.
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
Wind Survival Rating, mph (km/h)
Without Ice
With 0.5 in (12mm) Radial Ice
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
60
See Page 3
See Page 3
140 (230)
80 (125)
140 (230)
80 (125)
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
747FCD-2
747FCD-3
747FCD-7
747FCD-9
747FCD-11
747FCD-42
747FCD-43
747FCD-44
747FCD-47
747FCD-49
2-30
2-30
2-30
2-30
2-30
4-30
4-30
4-30
4-30
4-30
Bulletin 1411B 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
Type N
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