Description : For what class of operation is the final rf power amplifier of a plate-modulator circuit biased?
Last Answer : Class C
Description : What circuit section is required in the output of a multivibrator modulator to eliminate unwanted output frequencies?
Last Answer : An LCR filter.
Description : How much must the fpa plate current vary to produce 100- percent modulation in a plate modulator?
Last Answer : Between 0 and nearly two times its unmodulated value.
Description : The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an ... drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor
Last Answer : Answer: D
Description : What is the purpose of a modulator in a servo system?
Last Answer : To convert a dc error signal into an ac error signal.
Description : What modulator element controls the rate at which the storage element charges?
Last Answer : The charging impedance.
Description : What type of tube best meets the requirements of a modulator switching element?
Last Answer : Thyratron.
Description : What type of modulator is most commonly used in modern radar systems?
Last Answer : Line-pulsed.
Description : In addition to a flat top, what characteristics must a modulator pulse have?
Last Answer : Steep leading and trailing edges.
Description : What components may be used to build a basic phase modulator?
Last Answer : A phase-shift network such as a variable resistor and capacitor in series
Description : What characteristic of a varactor is used in an fm modulator?
Last Answer : Capacitance.
Description : What characteristic of a transistor is varied in a semiconductor-reactance modulator?
Last Answer : Collector-to-emitter capacitance.
Description : How does the reactance-tube modulator impress intelligence onto an rf carrier?
Last Answer : By changing the reactance of an oscillator circuit in consonance with the modulating voltage.
Description : What are the basic components of a thyratron modulator?
Last Answer : ower source, a circuit for storing energy, a circuit for discharging the storage circuit, and a pulse transformer.
Description : What is the primary component for a spark-gap modulator?
Last Answer : Either a fixed spark gap that uses a trigger pulse to ionize the air between the contacts, or a rotary gap that is similar to a mechanical switch.
Description : What causes the change in collector current in an emitter injection modulator?
Last Answer : Gain is varied by changing the voltage on the emitter.
Description : What type of modulator is the cathode modulator (low- or high-level)?
Last Answer : Low-level.
Description : When is a control-grid modulator used?
Last Answer : In cases when the use of a minimum of af modulator power is desired.
Description : The collector-injection modulator is similar to what type of tube modulator?
Last Answer : Plate modulator.
Description : What is the term used to identify the amount of field strength required to cause the electrons to just miss the plate and return to the filament in a circular orbit?
Last Answer : The critical value of field strength
Description : Which circuit detects frequency modulated signal? A. Modulator B. Discriminator C. Demodulator D. Modem
Last Answer : B. Discriminator
Description : What do you call a circuit that controls the magnetron output? A. Inverter B. Impeller C. Modulator D. Converter
Last Answer : C. Modulator
Description : Draw circuit diagram of transistor reactance modulator. Explain its working.
Last Answer : Explanation- A reactance modulator is illustrated in figure. It is basically a standard commonemitter class A amplifier. Resistors R1 and R2 from a voltage divider to bias ... frequency, whereas a lower capacitance increases the frequency. The circuit produces direct frequency modulations.
Description : Draw the circuit diagram of varactor diode FM modulator and explain its working.
Last Answer : Varactor diode modulator is the direct method of FM generation wherein the carrier frequency is directly varied by the modulating signal. A varactor diode is a semiconductor diode whose ... the magnitude of frequency change is proportional to the amplitude of the modulating signal voltage.
Description : An electrical device which prevents an action from occurring until all other required conditions are met is called a/an ___________. A. limit B. monitor C. modulator D. interlock
Description : What effect does the shielding of the screen grid by the control grid have on plate current in beam-forming tetrodes?
Last Answer : By increasing the number of electrons that reach the plate, plate current is increased.
Description : How does transit time affect the relationship of the grid voltage and the plate current at high frequencies?
Last Answer : Transit time causes the grid voltage and plate current to be out of phase
Description : Why does the grid have a greater effect than the plate on electron flo
Last Answer : Because it is closer to the cathode.
Description : A large negative voltage is applied to the plate of a diode, and a largewhat tube parameter has been exceeded?
Last Answer : Peak Inverse Voltage (PIV).
Description : A tube has a transconductance of 800 mhos and a load resistor of 50 kohms. When control grid voltage varies by 6 volts, the plate voltage will vary by what amount?
Last Answer : 240 volts.
Description : If the mu of a tube is 85 and the signal at the control grid is 4 volts ac, the plate voltage will vary by what amount?
Last Answer : 340 volts.
Description : The plate voltage of a tube will vary 126 volts when a 3-volt ac signal is applied to the control grid. What is the gain of this tube?
Last Answer : 42.
Last Answer : Modulator Horo Modem Of In full The first Part.it Digital To the signal Analog In the signal Transformed By
Description : In computing, how is a modulator-demodulator more commonly known?
Last Answer : Modem
Description : Zymogen is a (A) Vitamin (B) Enzyme precursor (C) Modulator (D) Hormone
Last Answer : Answer : B
Description : A substance unrelated to substrate but capable of reversibly changing activity of enzyme by binding to a site other than active site is called (a) Competitive inhibitor (b) Non-competitive inhibitor (c) Catalytic inhibitor (d) Allosteric modulator/inhibitor
Last Answer : Ans. ((d))
Description : In Nuclear reactors graphite is used as (1) Lubricant (2) Fuel (3) Linear of the reactor (4) Modulator
Last Answer : (4) Modulator Explanation: Nuclear reactors are used at nuclear power plants for electricity generation. These are generally graphite moderated and CO2 cooled.
Description : Which of the following is not usually a part of a transponder are defined by the A. LNA B. Mixer C. Modulator D. HPA
Description : Combination of modulator, channel and detector. A. Transceiver B. Discrete channel C. T/R channel D. Transponder
Last Answer : B. Discrete channel
Description : The output of a balanced modulator is ____________. A. LSB and USB B. LSB C. USB D. Carrier
Last Answer : A. LSB and USB
Description : In communication satellite, multiple repeaters are known as a. detector b. modulator c. stations d. transponders
Last Answer : transponders
Description : In a synchronous modem, the digital-to-analog converter transmits signal to the a. equilizer b. modulator c. demodulator d. terminal e. none of aobve
Last Answer : equilizer
Description : The term modem is a composite word that refers to the two functional entities that make up the device: asignal _______ and a signal _______. A) modulator; demodulator B) demodulator; modulator C) modern;demo D) none of the above
Last Answer : modulator; demodulator
Description : In OSI model at which layer modulator/demodulators are used? A. data link layer B. network layer C. session layer D. physical Layer
Last Answer : D. physical Layer
Description : The basic modulator and demodulator circuits in PSK are:
Last Answer : Balanced modulators