Design elements - VHF UHF SHF

The vector stencils library "VHF UHF SHF" contains 52 symbols for VHF, UHF, and SHF circuit design, including capacitance measurers, nonreciprocal devices, modulators, phase shifters, field polarization devices, and filters.
"Very high frequency (VHF) is the ITU-designated range of radio frequency electromagnetic waves from 30 MHz to 300 MHz, with corresponding wavelengths of one to ten meters. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).
Common uses for VHF are FM radio broadcasting, television broadcasting, land mobile stations (emergency, business, private use and military), long range data communication up to several tens of kilometres with radio modems, amateur radio, and marine communications. Air traffic control communications and air navigation systems (e.g. VOR, DME & ILS) work at distances of 100 kilometres or more to aircraft at cruising altitude.
VHF was previously used for analog television stations in the US." [Very high frequency. Wikipedia]
"Ultra-high frequency (UHF) designates the ITU radio frequency range of electromagnetic waves between 300 MHz and 3 GHz (3,000 MHz), also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres; that is 1 decimetre to 1 metre. Radio waves with frequencies above the UHF band fall into the SHF (super-high frequency) or microwave frequency range. Lower frequency signals fall into the VHF (very high frequency) or lower bands. UHF radio waves propagate mainly by line of sight; they are blocked by hills and large buildings although the transmission through building walls is high enough for indoor reception. They are used for television broadcasting (digital and analogue), cordless phones, walkie-talkies, satellite communication, and numerous other applications.
The IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. Two other IEEE radar band overlap the ITU UHF band: the L band between 1 and 2 GHz and the S band between 2 and 4 GHz." [Ultra high frequency. Wikipedia]
"Super high frequency (or SHF) is the ITU designation for radio frequencies (RF) in the range of 3 GHz and 30 GHz. This band of frequencies is also known as the centimetre band or centimetre wave as the wavelengths range from ten to one centimetres. These frequencies fall within the microwave band, so radio waves with these frequencies are called microwaves. The small wavelength of microwaves allows them to be directed in narrow beams by aperture antennas such as parabolic dishes, so they are used for point-to-point communication and data links, and for radar. This frequency range is used for most radar transmitters, microwave ovens, wireless LANs, cell phones, satellite communication, microwave radio relay links, and numerous short range terrestrial data links. The commencing wireless USB technology will be using approximately 1/ 3 of this spectrum.
Frequencies in the SHF range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations." [Super high frequency. Wikipedia]
The shapes example "Design elements - VHF UHF SHF" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.

The vector stencils library "Design elements - Electron tubes" contains 36 element symbols of electron tubes.
Use it for drawing electrical schematics and electronic circuit diagrams.
"One classification of vacuum tubes is by the number of active electrodes, (neglecting the filament or heater). A device with two active elements is a diode, usually used for rectification. Devices with three elements are triodes used for amplification and switching. Additional electrodes create tetrodes, pentodes, and so forth, which have multiple additional functions made possible by the additional controllable electrodes.
Other classifications are:
(1) by frequency range (audio, radio, VHF, UHF, microwave),
(2) by power rating (small-signal, audio power, high-power radio transmitting),
(3) by design (e.g., sharp- versus remote-cutoff in some pentodes),
(4) by application (receiving tubes, transmitting tubes, amplifying or switching, rectification, mixing),
(5) special qualities (long life, very low microphonic and low noise audio amplification, and so on).
Multiple classifications may apply to a device; for example similar dual triodes can be used for audio preamplification and as flip-flops in computers, although linearity is important in the former case and long life in the latter.
Tubes have different functions, such as cathode ray tubes which create a beam of electrons for display purposes (such as the television picture tube) in addition to more specialized functions such as electron microscopy and electron beam lithography. X-ray tubes are also vacuum tubes. Phototubes and photomultipliers rely on electron flow through a vacuum, though in those cases electron emission from the cathode depends on energy from photons rather than thermionic emission." [Vacuum tube. Wikipedia]
The symbols example "Design elements - Electron tubes" was drawn using the ConceptDraw PRO diagramming and vector drawing software extended with the Electrical Engineering solution from the Engineering area of ConceptDraw Solution Park.