Volume 1
MIL-HDBK-162A
Section 3
15 December 1965
ITEM NAME: INDICATOR GROUP
TYPE: AN/SPA-25(XN-1)
Detected radar targets are illuminated on the cathode
TECHNICAL DESCRIPTIONS
ray tube for measurement of range and azimuth. Range
Power Requirements: 180w, 115v, 60 cycles,
is measured by means of range marks and a range
single ph
strobe. Range marks appear on the cathode ray tube as
Range of Indicator
concentric rings spaced at accurate intervals to represent
Maximum: 300 mi
distance from the radar antenna. The range strobe
Minimum: 4 mi
appears as an expanding concentric ring, the expansion
Sweep Rate
of which is mechanically controlled by the operator.
Maximum: 40 rpm
When the range strobe ring is made to pass through a
Sweep Linearity: 1%
target, the target range is shown on a range-window on
Range Marks
the front panel. The range of a target at a distance of
Spacing in Miles: 1, 2, 5, 10, 25 and 50
twenty-eight miles or less is expressed in yards in a
Pulse Width: 1 plus or minus 1/4 usec
range-yards window. The range of a target beyond
Accuracy between Marks: 1%
twenty-eight miles is expressed in miles in a rangemiles
Range Strobe
window.
Pulse Width: 1.5 plus or minus 1/4 usec
Bearing is measured by means of an electronic
Accuracy
bearing cursor. The cursor appears as a sweep whose
0.15 - 5 Miles: 0.05 mi
azimuth is mechanically controlled by the operator. When
5 - 36 Miles: 1%
the bearing cursor is activated, normal video is blanked
36 - 300 Miles: 2%
from the presentation. The cursor crank control is then
Cranking Ratio: Approx 20 turns per
hand-operated to make the cursor pass through the target
300 mi
while the target is still glowing on the cathode ray tube.
Required Radar Input Trigger
The bearing thus determined is shown on the cursor-
Pulse Width: 1 to 1O usec
bearing window. The use of an electronic cursor provides
Amplitude: 5 to 50v
accurate bearing measurements since parallax, a fault
Repetition Rate: 6 to 3000
common to mechanical cursors, is eliminated.
Required Radio Video Input: 1 to 2.5v
RELATION TO SIMILAR EQUIPMENT
pos polarity.
None.
INSTALLATION CONSIDERATIONS
Related Equipment: (Required but not
Supplied) (1) Radar Set, AEW or DRA
Radar Relay Receiver (as required)
Shipboard, Multiple Armored Cable
MSCA-10; (as required) Shipboard
Multiple Armored Cable MSCA-14 or
MSCA-7; (as required) Coaxial Cable
RG-10/U; (2) Connector UG-111/U.
PRINCIPAL COMPONENTS AND PHYSICAL DATA
SHIPPING DATA
COMPONENTS
OVERALL DIMENSIONS
UNIT WT.
QTY
(Inches)
(Pounds)
Indicator
1
23-7/8 x 29 x 32
229
Accessory Case consisting of:
1
15-1/8 x 19-1/4 x 31
Reflector Plotter
1
Spray-Type Baffles
3
Patch Cable
1
Equipment Spares
1
EQUIPMENT SUPPLIED DATA
COMPONENTS
OVERALL DIMENSIONS
UNIT WT.
QTY
(Inches)
(Pounds)
Indicator
1
17-1/16 x 18-23/32 x 23-53/64
180
Accessory Case consisting of:
1
15-1/8 x 19-1/4 x 31
Reflector Plotter
1
Spray-Type Baffles
3
Patch Cable
1
AN/SPA-25(XN-1): 2
Previous Page
