| AS-2493/SRA-62 |
|
| Physical
Dimensions |
|
| Height |
52
inches |
| Width |
20
inches |
| Depth |
50
- 3/4 inches |
| Weight |
68
lbs |
| Operating
Temperature |
-62
C to +75 C |
|
|
| Frequency
Range |
225
to 400 MHz |
| Input
Impedance |
50
ohms |
| VSWR |
>
2:1 over freq range |
| Polarization |
Right-hand
circular and left-hand circular, alternating between
the four sector antennas |
| RF
Power Rating |
500
watts (average); 2000 watts peak |
| Power
Requirement |
None |
| Feed
Type |
Unbalanced,
coaxial cable |
| Input
Connector |
Type
N |
|
|
Description:
The AS-2493/SRA-62 isa component of the AN/SRA-62 Sector
Array UHF Antenna System. This system is composed of four
AS-2493/SRA-62 UHF Sector Antennas and one RF-247/SRA-62
Power Divider. The power divider allows all four sector
antennas to be fed from a single 50 ohm coaxial transmission
line. The system is used to provide omnidirectional coverage
for ship-to-air communications. Each antenna is made up of
two cross-log periodic antennas and a polarization network
to produce a circularly polarized signal.
Installation: The antennas may be mounted
directly to the ships structure or suitable mounting
platforms. The antenna array mounting brackets are drilled
to accommodate 3/8 inch bolts for this purpose. The antennas
should be located fore, aft, port, and starboard roughly in
a square around the superstructure. The polarization of the
antennas must be arranged so that there is a right-hand
polarized antenna port and starboard, and a left-hand
polarized fore and aft. This distance between the antennas
is not critical; however, the cables connecting the sector
antennas to the power divider should be carefully cut so
that the lengths are equal to within +/- l/4 inch.
Considerations: If it is necessary to increase
channel capacity, additional sector antennas may be mounted
on .the ships superstructure. The antennas on the same side
of the superstructure should be separated as far as possible
to provide isolation between systems. To further increase
isolation adjacent antennas should be oppositely polarized. |
