| AS-390/SRC |
|
| Physical
Dimensions |
|
| Height |
18
inches |
| Diameter |
23
inches |
| Weight |
3.625
lbs |
| Operating
Temperature |
-32
C to +150 C |
|
|
| Frequency
Range |
220
to 400 MHz |
| Input
Impedance |
50
ohms (nominal) |
| VSWR |
>
2:1 over freq range |
| Polarization |
Vertical |
| RF
Power Rating |
200
watts (average) |
| Power
Requirement |
None |
| Feed
Type |
Unbalanced,
coaxial cable |
| Input
Connector |
Type
N, special, mates with UG-21B/U |
|
|
Description:
The AS-390/SRC Antenna Assembly is an unbalanced broadband
coaxial stub antenna used for transmitting and receiving. It
consists of a radiator and ground plane. The ground plane
(or counterpoise) consists of eight elements bent downward
37 degrees from the horizontal. The lower ends of the
elements form points of a circle 23 inches in diameter. The
lower section of the radiator assembly contains a stub for
adjusting the input impedance of the antenna. This is
determined at time of manufacture and locked during final
assembly of the antenna. The antenna may be used with any
UHF transmitting and/or receiving equipment designed to
operate within its frequency range and RF power handling
limitations.
Installation: The base of the antenna assembly
is provided with a threaded 3/4" -14 IPS pipe 1-1/2"
long for use-in mounting the antenna. The antenna may be
installed to the ship's supporting structure, using a
matching size pipe and pipe coupling. The support pipe
should be welded to the ship's structure.
Considerations: The location for the AS-390/SRC
antenna onboard ship should be selected to provide maximum
unobstructed omnidirectional coverage within the physical
constraints of the ship's structure. UHF propagation is
generally line-of-sight and antennas that are masked by
surrounding structures produce limited coverage in azimuth
and/or elevation. The antenna is designed to be sufficiently
airtight to maintain a dielectrically stable atmosphere
within the antenna. The presence of moisture may be checked
by the removal of a pipe plug located on the underside of
the counterpoise plate. The antenna should not be located in
stack gas drafts or exhausts where the temperatures exceed
the operating temperature limitations. |
