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2-3Figure 2-1B.-Interelectrode capacitance in a vacuum tube. 100 MEGAHERTZ.Figure 2-1C.-Interelectrode capacitance in a vacuum tube. INTERELECTRODE CAPACITANCE IN ATUNED-PLATE TUNED-GRID OSCILLATOR.A good point to remember is that the higher the frequency, or the larger the interelectrodecapacitance, the higher will be the current through this capacitance. The circuit in figure 2-1C, shows theinterelectrode capacitance between the grid and the cathode (Cgk) in parallel with the signal source. Asthe frequency of the input signal increases, the effective grid-to-cathode impedance of the tube decreasesbecause of a decrease in the reactance of the interelectrode capacitance. If the signal frequency is 100megahertz or greater, the reactance of the grid-to-cathode capacitance is so small that much of the signalis short-circuited within the tube. Since the interelectrode capacitances are effectively in parallel with thetuned circuits, as shown in figures 2-1A, B, and C, they will also affect the frequency at which the tunedcircuits resonate.Another frequency-limiting factor is the LEAD INDUCTANCE of the tube elements. Since the leadinductances within a tube are effectively in parallel with the interelectrode capacitance, the net effect is toraise the frequency limit. However, the inductance of the cathode lead is common to both the grid andplate circuits. This provides a path for degenerative feedback which reduces overall circuit efficiency.
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What is the history of germanium diode?
Germanium point contact diodes were first created and used during World War 2 as detectors in microwave RADAR systems, as the vacuum tubes available at that time did not operate at microwave frequencies. Shortly after World War 2 germanium junction diodes were created.
How does a radio transmitter produce radio waves?
There are two primary types of electrical amplification available for any application. The first type, transistor amplification, is what you are most likely familiar with. This is the common form of amplification used today in most consumer products like radios and car amplifiers. However, before the invention of the transistor, vacuum tubes did the same job. Tubes are electrical switches mounted inside of glass enclosures that are under vacuo. They resemble light bulbs. In radio transmission, however, these vacuum tubes are commonly the size of a household clothes dryer. These tubes amplify the frequency before the voltage is sent up the radio station's transmission tower. At the top of the tower, a broadcast antenna is mounted. These antennae are special shapes and lengths that correspond to both the frequency and direction of the intended transmission.
How do bells and buzzers work?
A wind chime has several objects which produce a "chime" when they strike each other. When a wind chime is left hanging freely, the wind makes the objects move and they strike each other to produce a chiming sound.
How many vacuum tubes are in the Univac I computer?
It used 5200 vacuum tubes.
Can plastic specimen tubes use for sterilize?
As most plastics used in specimen tubes will melt if sterilized with heat the plastic tubes are normally single use
How do you overcome the limitations of conventional tubes at microwave frequency?
One way to overcome the limitations of conventional tubes at microwave frequencies is to use advanced technologies such as traveling-wave tubes (TWTs) or klystrons, which are specifically designed for high-frequency applications. These devices are capable of achieving higher power outputs and greater bandwidths compared to traditional tubes. Additionally, employing efficient cooling systems and advanced fabrication techniques can also help improve the performance of tubes at microwave frequencies.
What are the Limitation of conventional microwave tubes?
there are 6 limitations as bellow. 1. inter electrode capacitances. 2. lead inductances. 3. transit time. 4. RF loses effect. 5. gain bandwidth limitations. 6. radiations loses.
In what products do microwave tubes find application?
Microwave tubes were primarily used in high and ultrahigh frequency applications such as radars, telecommunications equipment, military communication and control systems
What has the author A S Gilmour written?
A. S. Gilmour has written: 'Principles of traveling wave tubes' -- subject(s): Traveling-wave tubes 'Microwave tubes' -- subject(s): Microwave tubes
What are the microwave tubes is based on the principal of velocity modulation?
The klystron and the traveling wave tube (TWT) are two types of microwave tubes based on the principle of velocity modulation. In these tubes, the electron beam's velocity is modulated by an external signal, leading to the amplification of microwave signals. These tubes are commonly used in radar systems, satellite communications, and other high-power microwave applications.
What is microwave tube?
microwave tubes are sometime called as vaccum eletrpn device... that are used to generate or amplify microwave radio frequencies.
What has the author Marvin Chodorow written?
Marvin Chodorow has written: 'Fundamentals of microwave electronics' -- subject(s): Microwave tubes
What has the author Cyril Henry Dix written?
Cyril Henry Dix has written: 'Microwave valves [by] C.H. Dix [and] W.H. Aldous' -- subject(s): Microwave tubes 'Microwave valves'
Why vacuum tubes are not preferred at microwave?
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)
how are microwaves radiation produced?
Microwaves are produced by an electronic device called a magnetron inside the microwave oven. The magnetron generates electromagnetic radiation at a frequency of around 2.45 gigahertz, which is then directed into the microwave cooking chamber to heat food by exciting water molecules within it.
Why do shorter tubes produce higher pitch sound?
Shorter tubes produce higher pitch sounds because they have a shorter length for the sound wave to travel through, resulting in a higher frequency of vibrations. This faster vibration rate creates a higher pitch sound compared to longer tubes which have a lower frequency.
What has the author G D Sims written?
G. D. Sims has written: 'Microwave tubes and semiconductor devices'
