Radar System Engineering

608 EXAMPLES OF RADAR SYSTEM DESIGN [SEC. 1510
delivered to the pulse transformer input is capacitively coupled to the
keep-alive connection of the TR tube. The delay in the pulse transformer
and magnetron is such that this pulse arrives at the TR tube
slightly before the r-f pulse arrives. This ensures that the TR tube will
fire, improving the crystal protection.
The complete duplexer assembly, which includes the magnetron, its
coaxial-output-to-waveguide adapter, the TR switch, the signal mixer,
and the AFC mixer, as well as a slotted section for SWR measurements, is
shown in Fig. 15.7.
The Receiver.—The receiver is conventional, with an i-f bandwidth
of 1.8 Me/see and an over-all gain of slightly more than 120 db. Instan-
FIG. 15.7.—Duplexing assembly. Two such units are included, one for upper-beam system
and one for lower-beam system.
taneous AGC circuits are provided and can be switched in or out at the
will of the operator. The AFC operates from a separate mixer and
amplifier and is of the hunt-lock type described in Sec. 12.7. Separate
receivers are used on the upper-beam and the lower-beam systems.
indicator Equipment.—The set described here was based on the idea
that full flexibility is required in the indicator complement. Both
B-scopes and PPI displays can be used, in numbers and with geographical
coverage determined by the radar location, the density of targets, and
the mission performed by the set.
All data voltages and power voltages for the indicators are supplied
from a central. point, the so-called ‘(power console, ” which houses the
antenna rotation controls, the transmitter switches, a servo-driven