Why vacuum tubes are not preferred at microwave?

Why vacuum tubes are not preferred at microwave?
by

1 Answer

Answer :

Actually three special purpose vacuum tubes were specifically designed for microwave usage and are in some cases still the least expensive way to work with high power microwave signals.These vacuum tubes are:cavity magnetron (first designed in WW2 for use in military RADARs, still used in some RADAR systems and as the microwave radiation source in all microwave cookers)klystron (still used in satellite communication, medical microwave equipment, and particle accelerators)traveling wave tube (still used in satellite communication, RADAR systems, and the electromagnetic compatibility (EMC) testing industry for immunity testing of electronic devices)
by
selected by

Related questions

Does anybody make vacuum tubes anymore? All I ever find are surplus.

Description : Does anybody make vacuum tubes anymore? All I ever find are surplus.

Last Answer : answer:Without details as to type, there are over 39,000 currently listed on eBay. I’d say they’re still manufactured since there’s also availability on Amazon.

Which of the following is not a feature of first generation computers A) They used vacuum tubes or valves as main electronic component B) They consumed lots of electricity and produced excessive heat C) They used machine language and assembly language to program the machine D) None of above

Description : Which of the following is not a feature of first generation computers A) They used vacuum tubes or valves as main electronic component B) They consumed lots of electricity and produced excessive heat C) They used machine language and assembly language to program the machine D) None of above

Last Answer : Answer : C

First generation computers used for memory A) vacuum tubes B) silicon chips C) magnetic drum D) RAM

Description : First generation computers used for memory A) vacuum tubes B) silicon chips C) magnetic drum D) RAM

Last Answer : Answer : C

Which electronic component was made out of semiconductor material? A) Vacuum tubes B) Transistors C) ICs D) All of above

Description : Which electronic component was made out of semiconductor material? A) Vacuum tubes B) Transistors C) ICs D) All of above

Last Answer : Answer : C

Who invented vacuum tubes? A) John Bardeen B) William Shockley C) Lee de Forest D) All of above

Description : Who invented vacuum tubes? A) John Bardeen B) William Shockley C) Lee de Forest D) All of above

Last Answer : Answer : C

What was the main disadvantage of vacuum tubes? A) They were larger in size B) They consumed a lot of electricity C) They produced heat and often burned out D) The operation cost was high

Description : What was the main disadvantage of vacuum tubes? A) They were larger in size B) They consumed a lot of electricity C) They produced heat and often burned out D) The operation cost was high

Last Answer : Answer : C

Why are vacuum tubes also called valves? A) Because they can amplify the weak signals and make them strong B) Because they can stop or allow the flow of current C) Both of above D) None of above

Description : Why are vacuum tubes also called valves? A) Because they can amplify the weak signals and make them strong B) Because they can stop or allow the flow of current C) Both of above D) None of above

Last Answer : Answer : B

The main electronic component used in first generation computers was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above

Description : The main electronic component used in first generation computers was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above

Last Answer : Answer : B

Chief component of first generation computer was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above

Description : Chief component of first generation computer was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above

Last Answer : Answer : B

First Generation computers used ______ for Circuitry and ________ for memory (A) Transistor and Magnetic Core (B) IC and Magnetic Memory (C) Vacuum tubes and Magnetic drum (D) IC and Magnetic Core

Description : First Generation computers used ______ for Circuitry and ________ for memory (A) Transistor and Magnetic Core (B) IC and Magnetic Memory (C) Vacuum tubes and Magnetic drum (D) IC and Magnetic Core

Last Answer : (C) Vacuum tubes and Magnetic drum

Which of the following statements comparing transistors and vacuum tubes is correct? A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons. B. A vacuum tube must have a heated cathode, where transistors do not. C. Neither transistors nor vacuum tubes require heat for electrons to flow. D. The anode of both transistors and vacuum tubes must be heated to give off electrons.

Description : Which of the following statements comparing transistors and vacuum tubes is correct? A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons. B. A vacuum tube must ... flow. D. The anode of both transistors and vacuum tubes must be heated to give off electrons.

Last Answer : Answer: B

Heat sinks are frequently used with _____________. A. power transistors B. vacuum tubes C. tunnel rectifier diodes D. all of the above

Description : Heat sinks are frequently used with _____________. A. power transistors B. vacuum tubes C. tunnel rectifier diodes D. all of the above

Last Answer : Answer: A

The method used to produce electron emission in most vacuum tubes is known as ____________. A. photoelectric emission B. secondary electric emission C. cold cathodic electric emission D. thermionic emission

Description : The method used to produce electron emission in most vacuum tubes is known as ____________. A. photoelectric emission B. secondary electric emission C. cold cathodic electric emission D. thermionic emission

Last Answer : Answer: D

The HPAs in most satellite are A. TWTs B. Klystrons C. Vacuum tubes D. Magnetrons

Description : The HPAs in most satellite are A. TWTs B. Klystrons C. Vacuum tubes D. Magnetrons

Last Answer : A. TWTs

Vacuum tubes have been replaced by-----? A. Conductors B. Diodes C. Transistors (Answer) D. None of these

Description : Vacuum tubes have been replaced by-----? A. Conductors B. Diodes C. Transistors (Answer) D. None of these

Last Answer : C. Transistors (Answer)

Pick out the wrong statement. (A) The value of hydrostatic head increases with increase in vacuum in the effect in a multiple effect evaporator system (B) Entering velocity of the liquid in the tubes of natural circulation evaporators is in the range of 0.3 to 0.9 metre/second (C) Duhring's plot is used for calculating the concentration of solution (D) In a multiple effect evaporation system, the number of effects is limited by the total boiling point rise

Description : Pick out the wrong statement. (A) The value of hydrostatic head increases with increase in vacuum in the effect in a multiple effect evaporator system (B) Entering velocity of the liquid in ... a multiple effect evaporation system, the number of effects is limited by the total boiling point rise

Last Answer : (C) Duhring's plot is used for calculating the concentration of solution

Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Description : Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Last Answer : Vacuum Tubes and Valves

This invention replaced vacuum tubes and made computers much smaller and faster. However, it was eventually replaced by another invention (i) RAM (ii) ENIAC (iii) Transformer (iv) Transistor.

Description : This invention replaced vacuum tubes and made computers much smaller and faster. However, it was eventually replaced by another invention (i) RAM (ii) ENIAC (iii) Transformer (iv) Transistor.

Last Answer : (iv) Transistor.

First generation computer systems used 1) Transistors 2) Vacuum tubes 3) Magnetic cores 4) Silicon chips

Description : First generation computer systems used 1) Transistors 2) Vacuum tubes 3) Magnetic cores 4) Silicon chips

Last Answer : 2) Vacuum tubes

Which electronic component was use in first generation? 1) Vacuum tubes 2) transistors 3) IC chips 4) all above

Description : Which electronic component was use in first generation? 1) Vacuum tubes 2) transistors 3) IC chips 4) all above

Last Answer : 1) Vacuum tubes

Which electronic component was use in first generation? 1 Vacuum tubes 2 transistors 3 IC chips 4 all above

Description : Which electronic component was use in first generation? 1 Vacuum tubes 2 transistors 3 IC chips 4 all above

Last Answer : 1 Vacuum tubes

How did vacuum tubes cause a problem for first generation computers

Description : How did vacuum tubes cause a problem for first generation computers

Last Answer : They were unreliable, required a lot of power to run, and produced so much heat that air conditioning was needed to protect computer parts.

In electronic computers, vacuum tubes were replaced by transistors and transistors have been replaced by what device?

Description : In electronic computers, vacuum tubes were replaced by transistors and transistors have been replaced by what device?

Last Answer : Integrated circuits.

When designing vacuum-tube circuits, what characteristics of tubes must be taken into consideration?

Description : When designing vacuum-tube circuits, what characteristics of tubes must be taken into consideration?

Last Answer : Differences in performance of tubes of the same type

Vacuum tubes are designed to operate in what portion of the Ep - Ip

Description : Vacuum tubes are designed to operate in what portion of the Ep - Ip

Last Answer : The linear portion.

Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Description : Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Last Answer : b. Vacuum Tubes and Valves

Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Description : Chief component of first generation computer was a. Transistors b. Vacuum Tubes and Valves c. Integrated Circuits d. None of above

Last Answer : b. Vacuum Tubes and Valves

Fifth generation computers do not have : (1) Speech recognition (2) Artificial intelligence (3) Very large scale integration (4) Vacuum tubes

Description : Fifth generation computers do not have : (1) Speech recognition (2) Artificial intelligence (3) Very large scale integration (4) Vacuum tubes 

Last Answer : Vacuum tubes

is Ohms law applicable to vacuum tubes?

Description : is Ohms law applicable to vacuum tubes?

Last Answer : Ohm's law is not applicable to vacuum tubes.

Microwave links are preferred for TV transmission because?

Last Answer : Microwave links are preferred for TV transmission because They produce less phase distortion

Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the possibility of tower wall collapse (B) Packed towers are preferred over plate towers for handling corrosive and foamy liquids (C) Diameter of randomly packed tower is normally more than 1.2 metres (D) Due to uneven supply and improper distribution of liquid, problem of channelling, loading & flooding is generally encountered in packed towers

Description : Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the ... of liquid, problem of channelling, loading & flooding is generally encountered in packed towers

Last Answer : (C) Diameter of randomly packed tower is normally more than 1.2 metres