replacement of components, assemblies, or
sub-assemblies, or (3) repair of certain units, assemblies
or sub-assemblies designated as “shipboard repairable.”
It may then require “turn in” of depot repairable
assemblies or sub-assemblies through prescribed supply
procedures.
All replaceable modules, assemblies or printed
circuit boards with a replacement value of 0 or more
(except the CRT and high-voltage power supplies) are
designed and constructed to be repairable by component
replacement at the depot maintenance level.
RANGE-HEIGHT INDICATOR (RHI)
The range-height indicator (RHI) scopes used with
height-finding radars obtain and display altitude
information. The RHI is a two-dimensional
presentation showing target range and altitude. An
example of a RHI presentation is shown in figure
2-15.
The sweep of a RHI starts in the lower left side of
the scope and moves across the scope to the right at an
angle that is the same as the angle of transmission of the
height-finding radar. The line of sight to the horizon is
indicated by the bottom horizontal line.
The point
Figure 2-15.—RHI presentation.
directly overhead in the sky (the zenith) is straight up
the left side of the scope. Targets are displayed as
vertical blips. Vertical range markers are provided to
estimate target range.
The operator determines altitude by adjust-
ing the moveable height line to the point where
it bisects the center of the target blip. Target
height is then read directly from altitude dials
(counters).
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