Radar System Engineering

624 EXAMPLES OF RADAR SYSTEM DESIGN [SEC. 1514
net weight of the components is about 120 lb. To this must be added 12
lb for cables and brackets, 28 lb for an inverter, and 25 lb for a radome,
so that the installed weight of the set is about 185 lb, well under a third
that of the AN/APQ-13. Snap fasteners and spring-loaded bands are
used as retaining elements to facilitate the removal and replacement of
units.
To achieve low weight and simplicity, many attractive design features
had to be sacrificed, including antenna stabilization, sector scan, groundrange
sweeps, and long pulses for maximum range performance. The
possibility of adding to the AN/APS-10 special units to perform special
functions has, however, been retained. A trigger pulse and video signals
are available for any attachment, as are provisions for an additional.
azimuth-angle take-off and means for externally reversing the azimuth
scan motor.
Adequate filtering and shielding are provided to deal with any
ordinary problems of mutual interference between the radar and other
electronic equipment installed in the same aircraft.
The transmitter-receiver is protected against changes in external
pressure by means of a rubber-gasket seal and pressure-tight cable
connectors. The r-f line is also sealed and is connected to a pressure
pump with a dryer ori its intake.
Internal and external fans are provided for the unit in which there
is the greatest heat dissipation-the transmitter-receiver. The internal
rise above ambient temperature in thk unit is 35”C.
All units except the scanner are shock-mounted. The r-f line between
the shock-mounted transmitter-receiver and the rigidly attached scanner
has a pressure-tight flexible section. Where possible, as in the case of the
transmitter-receiver, center-of-gravity shock mounts are used.
To minimize the effect of variations in supply voltage and waveform,
full-wave rectifier power supplies with choke-input filters are used
throughout the set. Electronic regulation of voltage has been used
where necessary to maintain precise voltage or to remove the lowfrequency
ripple found in the output voltage of many aircraft alternators.
Operational Suitability.—In contrast to the 24 controls of the AN/-
APQ-13, the AN/APS-10 has only 10. Four must be used often, four
infrequently, and the remaining two are primarily for the convenience
of the operator. The four commonly used controls are:
1. A range-selector switch that enables the operator to choose either
a continuously variable, 4- to 25-mile sweep or a 50-mile sweep for
search operation, or a O- to 90-mile or 70- to 160-mile sweep
primarily intended for beacon operation. Two-mile range marks
are provided on sweeps shorter than 14 miles, 10-mile marks on