| AS-1899/SLA-13A |
|
| Physical
Dimensions |
|
| Height |
15
- 1/2 inches
|
| Diameter |
37
inches |
| Weight |
112
lbs |
| Operating
Temperature |
-28
C to +65 C |
|
|
| Frequency
Range |
Unavailable
|
| Input
Impedance |
50
ohms |
| VSWR |
>
1.7:1 over freq range
|
| Polarization |
Circular,
either direction |
| RF Power
Rating |
50
kw peak, 25 kw average |
| Power
Requirement |
Control
and reference voltages all supplied from control
units |
| Feed
Type |
Unbalanced,
waveguide |
| Input
Connector |
Waveguide,
flange coupling |
|
|
Description:
TheAS-1899/SLA-13 is a unit of the AN/SLA-13A(U) Antenna
Group.Two AS-1899/SLA-13 Antennas are supplied with each
group. The antenna unit consists of a teflon radome,
aluminum base plate, and aluminum pedestal. The pedestal
contains the servo drive motor, gear reducer, azimuth
synchro generator, sector switch, and control circuitry. The
RF section consists of a rotary joint, circular polarization
phase shifter, and conical horn antenna. The circularly
polarized antennas may be used for direction finding or as
transmitting antennas. The group is generally used with the
AN/SLQ-12 Countermeasures Set. The antennas are installed
port and starboard with a switching arrangement that permits
360 coverage using the outboard 1800 sector coverage of each
antenna. Control of the antennas is from either the
C-6986/SLA-13A Main Control Unit or C-6987/SLA-13A Remote
Control Unit.
Installation: The base plate has four
shockmount mounts equally spaced on a 29 inch diameter. Each
shockmount has four 7/32 inch bolt holes for securing the
antenna to its mounting platform. The antennas are usually
mounted, port and starboard, on the same structure as the
active electronic countermeasures antennas. The antennas
should be located to maximum unobstructed coverage over
their sector. A center hole is required in the mounting for
access to the waveguide and control cable. The marks on the
top of the base plate must be aligned fore and aft with the
centerline of the ship.
Considerations: The sector cam switches in each
antenna must be adjusted during installation to select the
coverage areas of the individual antenna. The length of the
waveguide between antenna and its associated equipment
should be kept as short as possible to minimize attenuation. |
