2731 and 2004 Rotatable Log-Periodic Antennas

Type 2731 and 2004 Series GRANGER™
Rotatable Log-Periodic Antennas
2-30 MHz Frequency Range
Up to 25 kW Peak Power Rating,
Depending on Type
Horizontally Polarized
2.0: 1 VSWR
High Gain
Lightweight
Easy to Install and Maintain
Durable
High Efficiency- Up to 98%
Medium-and Long-Range
Communications
Two Versions-Full Tower Size
and Compact Roof Size
2731 Series Rotatable Log-Periodic
Antennas
General Description
Model 2731 wideband high power Rotatable Log-Periodic Antenna.
The 2731 Series RLPA Antennas are
comprised of wire radiators on a
strong and unusually light weight
support structure. These radiators are
full electrical length, providing
maximum possible efficiency. The
radiator curtains are also offered in
versions with optional electrical
loading permitting operation down to
2 MHz, with reduced efficiency and
with the pattern tending to become
high angle omnidirectional.
Features
Construction. The 2731 Series
Antennas are the most cost effective
of their class. The electrical and
structural designs are based upon
more than 2 years of experience.
Antennas are fabricated of materials
that have proven records of long life
through use in every conceivable
environment.
Rotation System
The 2731 Series Antennas may be
used without a rotator for fixed
direction services where their
compact, single mast construction is
advantageous.
The optional, 2500 series, electrical
rotator system incorporates a field
proven design with extra heavy-duty
chain drive.
The rotators of the 2731 Series
antennas utilize digital controls which
provide improved operation at greater
control distances. Antenna bearing
data and proper operation is
monitored and displayed at each
control point.
Control System is a microprocessor
based system consisting of three
units; a Master Control Unit (MCU)
normally situated in the transmitter
control room which is connected by
two shielded, twisted pairs (up to
4,000 ft., 1,200 metres) to an Antenna
control Unit (ACU) situated at the
base of the support mast. The ACU
houses the necessary circuits and
relays to control the starting and
stopping of the Antenna Rotator Unit,
which is located at the top of the
mast. Azimuth position, sensed by a
digital shaft encoder located in the
antenna rotator, is processed and fed
back through the ACU to the MCU
where selection of desired azimuth is
made. Direction is indicated on threedigit LED display.
Remote Control Systems
The 2500 Series Antenna Rotator
1
With the microprocessor operation it
is possible to arrange that the MCU
communicate with up to nine ACU’s.
Each antenna with its associated ACU
is allocated a different identifying
number during the initial installation.
In use, the number of the antenna to
be controlled is selected on the MCU
by means of a push button decimal
switch.
Extended Remote Control
It is also possible to control the
antenna system remotely by using a
second MCU located at a remote
terminal. Commands originated on
the remote MCU will be received by
the MCU and passed on to the ACU.
For remote operation greater than
4,000 ft. (1,220 metres) an FSK
(Frequency Shift Keying) system
transmitted over telephone lines of a
radio link is available. Line isolating
transformers are available to meet
local PTT regulations as an option. A
primary application is to relocate the
operation of a receiving and/or
transmitting antenna from remote
sites to a central operations building.
Tower Lighting
A kit of lighting units is available for
installation on the 2731 Series
Antennas. The units provide
obstruction lighting to meet all federal
and commercial specifications.
Lighting kits are typically required
when a 2731 Series Antenna is
installed near an airport.
Typical Elevation Plane Radiation
Patterns
Erection Equipment (Optional)
Erection Kit with Manual Winch.
Includes manual winch, gin pole,
stabilization guys and rigging
equipment.
Erection Kit with 115 VAC, 60 Hz
Electrical Winch. Includes same as
above with 115 VAC, 60 Hz electric
winch.
Erection Kit with 230 VAC, 50 Hz
Electric Winch. Includes same as
above with 230 VAC, 50 Hz electric
winch.
Rigging Tool Kit. For tower assembly
and guy tensioning.
Characteristics
Polarization
Gain, 4-30 MHz
Directional Gain, 2-4 MHz
Front to Back Ratio
Azimuth Beamwidth (at half power points)
Cross Polarization
VSWR
Wind & Ice Capabilities Survival Rating, mph (km/h)
Without Ice
With 0.5 in (12mm) Radial Ice
Rotation*
Tower Height**
AC Power Required
Horizontal
10 dBi nominal
8 dBi nominal
14 dB nominal
70° nominal
20 dB nominal
2:1
140 (225)
87 (139)
360°
100 ft (30 m)
115/230 VAC; 50/60 Hz, 2 KVA
* Available without rotator and control for fixed bearing operation.
** Towers 60 ft (18.3 m) and 80 ft (24.4 m) are also available.
2
Ordering Information
Type
Number*
Freq. Range
MHz
Power
kW
2731A-1-1
2731A-1-2
2731A-1-3
2731A-1-4
2731A-11-41
4-30
4-30
4-30
4-30
2-30†
25
10
5
1
Receive
Input
Connector
Female
3-1/8” EIA
1-5/8” EIA
7/8” EIA
Type N Jack
Type N Jack
F/B Ratio
dB
VSWR
Max.
Efficiency, Percent
Turning
Radius ft (m)
14
14
14
14
Up to 14
2.0
2.0
2.0
2.0
2.0
49 (14.9)
49 (14.9)
49 (14.9)
49 (14.9)
49 (14.9)
Directional gain
7 to 12
Up to 14
2.0
3-1/8” EIA
1-5/8” EIA
7/8” EIA
Type N Jack
Type N Jack
10
10
10
10
Directional gain
5 to 12
14
14
14
14
Up to 14
2.0
2.0
2.0
2.0
2.0
Type N Jack
Directional gain
5 to 12
Up to 14
2.0
98
98
98
98
90-98 (4.0 -30 MHz)
25-90 (3.0-4.0 MHz)
10-25 (2.0-3.0 MHz)
90-98 (4.0-30 MHz)
25-901 (3.0-4.0 MHz)
10-25 (2.0-3.0 MHz)
98
98
98
98
90-98 (5.8-30 MHz)
25-90 (3.0-5.8 MHz)
6-25 (2.0-3.0 MHz)
90-98 (5.8-30 MHz)
25-90 (3.0-5.8 MHz)
6-25 (2.0-3.0 MHz)
2731A-11-42
2-30†
1
Type N Jack
2731A-2-1
2731A-2-2
2731A-2-3
2731A-2-4
2731A-21-41
5.8-30
5.8-30
5.8-30
5.8-30
2-30†
25
10
5
1
Receive
2731A-21-42
2-30†
1
Gain, dBi
10 to 12
10 to 12
10 to 12
10 to 12
Directional gain
7 to 12
49 (14.9)
34 (10.3)
34 (10.3)
34 (10.3)
34 (10.3)
34 (10.3)
34 (10.3)
* Rotation option must be specified separately.
†Electrically loaded. VSWR increases below 4 MHz to a value of approximately 3.0:1 at 2 MHz.
Typical Azimuth Plane Radiation
Pattern Data (all frequencies)
Model 2731 Elevation Plane
Radiation Pattern Data (Antenna
mounted on 100 ft (30 m) tower) Scale in dB
relative to beam maximum
3
Model 2004 rooftop general purpose Rotatable
Log-Periodic Antenna (RLPA) mounted on SelfSupporting Articulated Tower* (SSAT), also
suitable for ground mount applications.
Other support masts include the fixed
2004 Series Compact Rooftop
or guyed 23 ft (7 m), 33 ft (10 m) or 43
Rotatable Log- Periodic
ft (13.1m) rooftop versions, or ground
Antennas
masts which range from 23 ft (7 m) to
(RLPA)
78 ft (24 m). (See Application Note 3,
General Description
Bulletin 1538.)
The 2004 Series general purpose
rooftop antenna provides both private
Rotator Unit
and governmental organizations
Type 2004 Series RLPA antennas are
efficient directed communications
supplied with a heavy-duty electrical
capability. Embassies, airports, headrotator unit/ Antennas may be
quarter buildings, oil companies and
ordered, however, without the rotator
other similar organizations utilize this
if a fixed bearing system is all that is
compact rotatable array.
required.
Application
In many cases, 2004 Series Antennas
The rotator mounts within the tripod
are installed on the roofs of buildings
at the top of the mast tower. The
which are pitched or have many
remote control panel is connected by
obstructions. The reduced turning
multicore power and control cable to
radius of 23 ft (7m) decreases the
the rotator unit. An extended remote
chance of physical interference.
control (ERC) system can be supplied
The arrays are designed with fully
by special order.
efficient half-wave radiators. There is
no electrical loading on the basic
Extended Frequency Capability
types. The wire radiators are sloped
As an option, the 6.2 MHz version
forward to be less obtrusive and so
antenna is offered with its lowest
require less turning room than the
operating frequency extended down
conventional tubular construction
to 2.0 MHz through use of a suitable
antenna arrays.
balun and electrical loading.
The 2004 Series Antennas are
horizontally polarized, conservatively
Optional Accessories
rated for full power with a continuous
duty cycle and can withstand 100 mph
Control and power cable
(160 km/h) wind and 50 mph (80
Erection kit
km/h) wind with ½ in (13 mm) ice.
Tower lighting kit
Paint kit
Support Mast Options
Spares kit
A sturdy, self-supporting articulated
tower (SSAT ) can be used in the 23 ft
(7 m) or 33 ft (10 m) versions for rapid
installation in a confined area. With
erecting hardware installed, the
permanent SSAT can elevate the 2004
Series Antennas in three minutes.
4
Ordering Information *
Type
Number
Freq.
Range
MHz
Peak
Azimuth
Beam
Width
Input
Connector
Gain
F/B
Ratio
VSWR
nom.*
*
Freq.
Band
MHz
Efficiency
Percent
Turning
Radius
ft (m)
7.5-30
Power
Rating
kW
Average
1
2004-2
2
70°
50 ohm
Type N Jack
8 dBi @7.5 MHz
12 [email protected] MHz
12
2.0:1
7.5-30
22.8
(6.95)
2004-3
6.2-30
1
2
70°
50 ohm
Type N Jack
7 dBi@ 6.2 MHz
12 dBi@ 30 MHz
12
2.0:1
6.2-30
2004-31
2.0-30
Receive
Only
Receive
Only
70° above
6 MHz
50 ohm
Type N Jack
7 dBi@ 6.2 MHz
12 dBi@ 30 MHz
12
2.0:1
2004-32
2.0-30
1
2
70° above
6 MHz
50 ohm
Type N Jack
7 dBi@ 6.2 MHz
12 dBi@ 30 MHz
12
2.0:1
2004-4
10.0-30
1
2
70° above
6 MHz
50 ohm
Type N Jack
10 [email protected] MHz
12 dBi@ 30 MHz
12
2.0:1
6.2-30
5.4-6.2
4.4-5.4
2.0-4.4
6.2-30
5.4-6.2
4.4-5.4
2.0-4.4
10-30
98
No
Electrical
Loading
98
No
Electrical
Loading
90 to 98
50 to 90
25 to 50
5 to 25
90 to 98
50 to 90
25 to 50
5 to 25
98
No
Electrical
Loading
* Complete type number requires addition of mast
option from the following table.
Rotation option must be specified separately.
28.5
(8.7)
28.5
(8.7)
28.5
(8.7)
17.76
(5.4)
* * VSWR depends up the height of the array above ground and the
influence of unkown adverse factors in build-up areas, such as rooftops where the antenna may be installed.
Mast Option Table
Mast
Guyed 17” Face Steel Tower
Model 4000 SSAT
(Self-Supporting Articulated
Tower)
Height* ft(m)
23 (7.0)
33 (10.0)
43 (13.1)
63 (19.2)
78 (23.8)
23 (7.0)
33 (10.0)
Roof Mount
-11
-12
-13
-14
-15
Ground Mount
-21
-22
-23
-24
-25
-26
-27
* Overall height includes triangular tower top.
Bulletin 1423D 05/08 Data subject to change without notice.
5
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