18
3-10. Which of the following circuits produces
currents that deflect the electron beam
across the crt?
1. Gate
2. Sweep control
3. Sweep generator
4. Intensity gate generator
3-11. Electromagnetic deflection is preferred
over electrostatic deflection in ppi scopes
because it provides which of the
following advantages?
1. Better control of the beam
2. Better beam position accuracy
3. Better deflection sensitivity
4. All of the above
3-12. Focusing is accomplished in an
electromagnetic crt by varying the
1. potential on the deflection plates
2. potential between the first anode and
the cathode
3. current through the coil around the
neck of the tube
4. do bias current in the deflection coils
3-13. Because the electromagnetic crt uses
magnetic deflection, the sweep circuits
must provide the deflection coils with
which of the following signals?
1. Linear trace current
2. Trapezoidal voltage
3. Sinusoidal voltage
4. Direct current
3-14. In a ppi scope that uses electromagnetic
deflection, the amplitudes and polarities
of the sawtooth currents are determined
by which of the following inputs?
1. Target position and speed
2. Antenna rotation speed
3. Antenna position
4. Both 2 and 3 above
3-15. On the screen of a ppi scope, range
markers appear as
1. vertical pulses
2. radial grid lines
3. concentric circles
4. horizontal grid lines
3-16. The range sweep in a range-gate
generator is started at the same time the
transmitter fires. A pulse from which of
the following circuits causes this timing?
1. Receiver
2. Indicator
3. Transmitter
4. Synchronizer
3-17. When used with a ppi presentation, a
range gate must have which of the
following characteristics?
1. Movable in range
2. Movable in bearing
3. Both 1 and 2 above
4. Fixed in range and bearing
3-18. Range-markers are produced on the basis
of which of the following timing
constants?
1. Radar mile
2. Transmitter prf
3. Receiver bandwidth
4. Transmitter pulse width
3-19. To read range directly, the range step is
placed in what position relative to an
echo pulse?
1. The range step is centered on the
echo pulse
2. The range step coincides with the
leading edge of the echo pulse
3. The range step coincides with the
trailing edge of the echo pulse
4. The range step covers the entire echo
pulse
