| AS-1018/URC |
|
| Physical
Dimensions |
|
| Height |
72
- 3/8 inches |
| Diameter |
13
- 1/2 inches |
| Weight |
50
lbs |
| Operating
Temperature |
-32
C to +52 C |
|
|
| Frequency
Range |
225
to 400 MHz |
| Input
Impedance |
50
ohms (nominal) |
| VSWR |
>
2:1 over freq range |
| Polarization |
Vertical |
| RF
Power Rating |
2
kilowatts (average) |
| Power
Requirement |
None |
| Feed
Type |
Unbalanced,
coaxial cable |
| Input
Connector |
Type
N, UG-352B/U |
|
|
Description:
The AS-1018/URC Antenna is a broadband omnidirectional UHF
communications antenna. It is a collinear array of two
cylindrical parallel-fed dipole elements. The nonresonant
dipoles provide broadband coverage and a horizontal pattern
that is omnidirectional within +/- 1.0 dB. The lower half
power point of the vertically polarized radiation pattern
falls on or slightly below the horizon. Pattern tilt is
accomplished by feeding the dipoles in such a manner that
the upper dipole lags the lower dipole in phase by a few
degrees. The vertical propagation upward is required to fill
the cone of silence. The upper dipole is altered to provide
both horizontal and vertical components, thus producing the
required upward propagation. The dipole elements and
internal transmission line are enclosed in a polyester
fiberglass mast. This antenna may be used with any UHF
transmitting and/or receiving set designed to operate within
its frequency range and RF power handling limitations.
Installation: The antenna assembly mounting
flange has eight 7/8 inch diameter bolt holes on an 11-3/4
inch bolt circle. The antenna may be installed to the ship's
structure by a suitable mounting plate having matching bolt
holes. The mounting plate must have a center hole to
accommodate the antenna transmission line.
Considerations: The location for the
AS-1018/URC Antenna onboard ship should be selected to
provide maximum unobstructed 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. At the time of installation the antenna
should be purged to remove any moisture or damp air
entrapped within the enclosure. Purging should be
accomplished in accordance with the procedures outlined in
the equipment technical manual. |
