Radar System Engineering

SEC. 1514] L)I?T.4 ILED L).ESIG.V OF THE A.Y”/APS-10 625
sweeps between 15 and 50 miles, and 20-mile marks on the beacon
sweeps.
2. A recei~’er gain control.
3. A tilt control for the antenna. This enables adjustment of the
depression angle of the radar beam to the optimal value for any
altitude. A tilt meter calibrated in altitude is provided; it serves
as an approximate guide to the correct setting.
4. A search-beacon switch.
The controls less often used are:
1. The OFF-ONswitch.
2. The focus control of the indicator.
3. The brilliance control of the indicator.
4. The trim control. This enables the operator to adjust the scanner
mechanism in pitch so as to keep the axis of the scanner vertical
despite changing attitude in flight due, for example, to consumption
of fuel. A fore-and-aft bubble level and a hand crank connected
by flexible shaft to the scanner are provided.
The two “convenience” cent rols are the adjustments for range-mark
intensity and for dial-light brilliance.
The operation of the AN-/APS-10 is so simple that an hour’s flight
experience is sufficient to qualify a navigator to adjust and use the set.
For ease in maintenance, all units of the set have been made independently
replaceable, with no need of adjustment for individual units.
Even within the major units of the set, subassemblies have been designed
for replacement in the event of failure.
External test points” have been provided on the transmitter-receiver
and the synchronizer power supply to aid in identifying defective units
in cases of failure. On the transmitter-receiver these include a test
trigger from the modulator, an extra video channel, and a lead from a
directional coupler which enables r-f checking. On the synchronizer
po\ver supply pin jacks are provided to permit measurement of powersupply
voltages. Other test points are incorporated on many of the
subclasses of the transmitter-receiver unit. These external test points
permit a routine procedure of inspection and preventive maintenance to
detect incipient failure and insure peak performance.
The consensus of its users is that the AX/APS-10 fits its requirements
~reil. Further improvement in lightness, convenience, and modesty of
power demand will follow on general advance in the art, and in particular
on detailed attention to component design. To mention one example,
the substitution of subminiature tubes for larger standard types will
reduce bulk, weight, and po\ver consumption.