Electrical Symbols — Transformers and Windings

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 "Telecommunication networks" contains 32 clipart images of telecommunication network devices and equipment for drawing telecom network diagrams.
"A telecommunications network is a collection of terminal nodes, links and any intermediate nodes which are connected so as to enable telecommunication between the terminals.
The transmission links connect the nodes together. The nodes use circuit switching, message switching or packet switching to pass the signal through the correct links and nodes to reach the correct destination terminal.
Each terminal in the network usually has a unique address so messages or connections can be routed to the correct recipients. The collection of addresses in the network is called the address space." [Telecommunications network. Wikipedia]
The clip art example "Telecommunication networks - Vector stencils library" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Telecommunication Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.