| AS-2875/SRC |
|
| Physical
Dimensions |
|
| Height |
177
inches |
| Width |
24
inches (base) |
| Depth |
28
inches (base) |
| Weight
(antenna) |
150
lbs |
| Weight
(base) |
180
lbs |
| Operating
Temperature |
-54
C to +65 C |
|
|
| Frequency
Range |
2
to 6 MHz |
| Input
Impedance |
50
ohms |
| VSWR |
Fine
tuning VSWR > 2:1; coarse tuning > 10:1 |
| Polarization |
Vertical |
| RF
Power Rating |
1
kilowatt (average) |
| Power
Requirement |
Control
voltages supplied by control group. |
| Feed
Type |
Unbalanced,
coaxial cable |
| Input
Connector |
Type
HN |
|
|
Description:
Antenna AS-2875/SRC is a helical monopole, omnidirectional
transmitting and receiving antenna. It is used with Antenna
Set OE-156/SRC. The complete OE-156/SRC consists of five
AS-2875/SRC and five AS-2876/SRC antennas, and Control Group
OK-244/SRC. The OK-244/SRC controls the tuning of each
antenna under the direction of an external computer. The
AS-2875/ SRC is enclosed in a fiberglass radome. The base of
the antenna houses the electronic assembly. This assembly
contains circuits that respond to control signals from the
control group to rotate the radiating antenna. As the
antenna rotates, a tuning sleeve moves up or down the helix
changing its electrical length to tune the antenna.
Installation: The base mounting flange has
fourteen 13/16 inch diameter bolt holes for 3/4 inch bolts
around its periphery. Cable connections for RF input, servo
power input and antenna data are located on the base
casting. Two 3/8-16 inch tapped holes are located on the
base mounting flange for attaching bond straps.
Considerations: The antenna is secured to a
hinged plate that permits the antenna to be manually tilted
90 degrees. This hinged plate is released from the base by a
quick-release pin and the antenna lowered by operating a
pivot mechanism consisting of a rack and pinion actuator. A
charging valve and pressure indicator for use in purging and
charging the antenna with dry air or nitrogen are located on
the base. The antenna .is normally pressurized to 2 psig.
The coaxial and control cables to the base of the antenna
should have sufficient slack to permit lowering the antenna
without stretching the cables. |
