10
2-19. In order that nearby targets may be
detected, which of the following
characteristics must the transmitted pulse
have?
1. A steep leading edge
2. A steep trailing edge
3. A sloping leading edge
4. A sloping trailing edge
2-20. Compared to the hard-tube modulator,
the line-pulsing modulator has which of
the following advantages?
1. It is more complex
2. It is more efficient
3. It is more sensitive to voltage
changes
4. It requires a higher power-supply
voltage
2-21. The modulator of a radar basically
consists of a power supply, a switch, a
storage element, and a/an
1. IF strip
2. oscillator
3. transmitter
4. charging impedance
2-22. Which of the following devices can be
used as the storage element in a radar
modulator?
1. A capacitor
2. A pulse-forming network
3. An artificial transmission line
4. Each of the above
2-23. A signal introduced at the input end of an
artificial transmission line moves through
the circuit to the output end and is
reflected back to the input. The output
end of an artificial transmission line
appears to the input signal as what type
of circuit?
1. Open
2. Short
3. Inductive reactance
4. Capacitive reactance
2-24. The discharge pulse from the artificial
transmission line causes a voltage of
what magnitude to appear across the
primary of the pulse transformer?
1. Twice the original charge voltage
2. One-half the original charge voltage
3. The same as the original charge
voltage
4. One-fourth the original charge
voltage
2-25. What parameter, if any, of the output
pulse from an artificial transmission line
is affected by the inductance and
capacitance of each section of the line?
1. Width
2. Amplitude
3. Frequency
4. None of the above
2-26. A pulse-forming network exhibits
electrical behavior similar to which of
the following devices?
1. A resistance-capacitance network
2. An artificial transmission line
3. A capacitor
4. An inductor
2-27. The requirements of a modulator switch
are to (1) reach full conduction quickly,
(2) consume low power, (3) start and
stop conduction suddenly, and (4)
conduct high currents and handle high
voltages. Which of the following tubes
meets these requirements?
1. A tetrode
2. A thyratron
3. A magnetron
4. A beam-powered amplifier
