 Two coupled MHV elbows showing both plug and jack ends. | |||
| Type | RF coaxial connector | ||
|---|---|---|---|
| Production history | |||
| Manufacturer | Various | ||
| General specifications | |||
| Diameter | Male: 0.385 in (0.98 cm) (inner, bayonet) [1] Female: 0.378 in (0.96 cm) (outer, typical) [1] | ||
| Cable | Coaxial | ||
| Passband | Typically 0–300 MHZ | ||
| Electrical | |||
| Max. voltage | 5000Vpk | ||
| Max. current | 3A | ||
The MHV (miniature high voltage) connector is a type of RF connector used for terminating coaxial cable. [2] [3] [4]
The connector looks almost identical to a typical BNC connector, but is designed to not mate with BNC jacks. It features two bayonet lugs on the female connector; mating is fully achieved with a quarter turn of the coupling nut. The dimensions of the connector are specified in the MIL-STD-348B. MHV connectors can be recognized by the slightly protruding insulation on the male plug and the slightly different insulation length in the female jack.
The MHV connector is typically rated for 1500 VRMS continuous and 5000 V peak, and 3 amperes. With an operating frequency limited to about 300 MHz their usage is restricted to low frequency applications. [2] [3] [4] [1] It was commonly used in laboratory settings for voltages beyond the rating of BNC connectors. Other applications include:
MHV connectors are a safety hazard because the central pin is close enough to the end to allow accidental contact with it when the connector is not plugged in, [5] [6] [3] and because the ground connection is broken before the power connection when demating. [4]
An additional problem is that MHV connectors are easily mistaken for BNC connectors by users who are unaware of the difference, and MHV and BNC plugs and jacks can be made to mate by brute force. [3] This causes safety hazards, since a user can mate a low voltage cable to a high voltage jack.
SHV connectors are designed to prevent these hazards, and cannot be mated to BNC connectors. [3]
Coaxial cable, or coax, is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ; many coaxial cables also have a protective outer sheath or jacket. The term coaxial refers to the inner conductor and the outer shield sharing a geometric axis.
The BNC connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. It is designed to maintain the same characteristic impedance of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections.
Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. Most electrical connectors have a gender – i.e. the male component, called a plug, connects to the female component, or socket. The connection may be removable, require a tool for assembly and removal, or serve as a permanent electrical joint between two points. An adapter can be used to join dissimilar connectors.
The N connector is a threaded, weatherproof, medium-size RF connector used to join coaxial cables. It was one of the first connectors capable of carrying microwave-frequency signals, and was invented in the 1940s by Paul Neill of Bell Labs, after whom the connector is named.
The TNC connector is a threaded version of the BNC connector.
A balun is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line. A balun can take many forms and may include devices that also transform impedances but need not do so. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. Common-mode chokes are also used as baluns and work by eliminating, rather than rejecting, common mode signals.
In electronics, electrical termination is the practice of ending a transmission line with a device that matches the characteristic impedance of the line. Termination prevents signals from reflecting off the end of the transmission line. Reflections at the ends of unterminated transmission lines cause distortion, which can produce ambiguous digital signal levels and misoperation of digital systems. Reflections in analog signal systems cause such effects as video ghosting, or power loss in radio transmitter transmission lines.
The C connector is a type of RF connector used for terminating coaxial cable. The interface specifications for the C and many other connectors are referenced in MIL-STD-348. The connector uses two-stud bayonet-type locks. The C connector was invented by Amphenol engineer Carl Concelman. It is weatherproof without being overly bulky. The mating arrangement is similar to that of the BNC connector. It can be used up to 11 GHz, and is rated for up to 1500 volts.
SMA connectors are semi-precision coaxial RF connectors developed in the 1960s as a minimal connector interface for coaxial cable with a screw-type coupling mechanism. The connector has a 50 Ω impedance. SMA was originally designed for use from DC (0 Hz) to 12 GHz, however this has been extended over time and variants are available to 18 GHz and 26.5 GHz. There are also mechanically compatible connectors such as the K-connector which operate up to 40 GHz. The SMA connector is most commonly used in microwave systems, hand-held radio and mobile telephone antennas and, more recently, with WiFi antenna systems and USB software-defined radio dongles. It is also commonly used in radio astronomy, particularly at higher frequencies (5 GHz+).
SMB connectors are coaxial RF connectors developed in the 1960s. SMB connectors are smaller than SMA connectors.
SMC connectors are coaxial RF connectors developed in the 1960s. The interface specifications for the SMC and many other connectors are referenced in MIL-STD-348. They use a #10-32 UNF threaded interface. They offer electrical performance from direct current (DC) to 4 GHz. Some extended performance versions are rated to 10 GHz. The normally free part of a SMC connector that has a socket for the centre contact are the female connectors. The normally fixed part SMC connectors that has a pin for the centre contact are the male connectors. This is the reverse of most RF connectors. SMC jack connectors have an external thread while SMC plug connectors have the mating hex nut. The contact dimensions are identical to the snap-fit SMB. Available in 50 ohm and 75 ohm characteristic impedance, they provide an interconnect means for small form factor coaxial cables and printed circuit boards where small footprint is important.
A banana connector is a single-wire electrical connector used for joining wires to equipment. The term 4 mm connector is also used, especially in Europe, although not all banana connectors will mate with 4 mm parts, and 2 mm banana connectors exist. Various styles of banana plug contacts exist, all based on the concept of spring metal applying outward force into the unsprung cylindrical jack to produce a snug fit with good electrical conductivity. Common types include: a solid pin split lengthwise and splayed slightly, a tip of four leaf springs, a cylinder with a single leaf spring on one side, a bundle of stiff wire, a central pin surrounded by a multiple-slit cylinder with a central bulge, or simple sheet spring metal rolled into a nearly complete cylinder. The plugs are frequently used to terminate patch cords for electronic test equipment such as laboratory power supply units, while sheathed banana plugs are common on multimeter probe leads.
In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. The female connector is generally a receptacle that receives and holds the male connector. Alternative terminology such as plug and socket or jack are sometimes used, particularly for electrical connectors.
Crimping is a method of joining two or more pieces of metal or other ductile material by deforming one or both of them to hold the other. The bend or deformity is called the crimp. Crimping tools are used to create crimps.
The UHF connector is a name for a threaded RF connector. The connector design was invented in the 1930s for use in the radio industry, and is a shielded form of the "banana plug". It is a widely used standard connector for HF transmission lines on full-sized radio equipment, with BNC connectors predominating for smaller, hand-held equipment.
RG-59/U is a specific type of coaxial cable, often used for low-power video and RF signal connections. The cable has a characteristic impedance of 75 ohms, and a capacitance of around 20pF/ft (60pF/m). The 75 ohm impedance matches a dipole antenna in free space. RG was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System. The suffix /U means for general utility use. The number 59 was assigned sequentially. The RG unit indicator is no longer part of the JETDS system (MIL-STD-196E) and cable sold today under the RG-59 label does not necessarily meet military specifications.
The SHVconnector is a type of RF connector used for terminating a coaxial cable. The connector uses a bayonet mount similar to those of the BNC and MHV connectors, but is easily distinguished due to its very thick and protruding insulator. This insulation geometry makes SHV connectors safer for handling high voltage than MHV connectors, by preventing accidental contact with the live conductor in an unmated connector or plug. The connector is also designed such that when it is being disconnected from a plug, the high voltage contact is broken before the ground contact, to prevent accidental shocks. The connector is also designed to prevent users from forcing a high voltage connector into a low voltage plug or vice versa, by reversing the gender compared to BNC. Details of the connector comprising dimensions of the mating parts, voltage rating, minimum insulation requirements and more are specified by the IEC document 60498.
Electrical or fiber-optic connectors used by U.S. Department of Defense were originally developed in the 1930s for severe aeronautical and tactical service applications, and the Type "AN" (Army-Navy) series set the standard for modern military circular connectors. These connectors, and their evolutionary derivatives, are often called Military Standard, "MIL-STD", or (informally) "MIL-SPEC" or sometimes "MS" connectors. They are now used in aerospace, industrial, marine, and even automotive commercial applications.
Audio connectors and video connectors are electrical or optical connectors for carrying audio or video signals. Audio interfaces or video interfaces define physical parameters and interpretation of signals. For digital audio and digital video, this can be thought of as defining the physical layer, data link layer, and most or all of the application layer. For analog audio and analog video these functions are all represented in a single signal specification like NTSC or the direct speaker-driving signal of analog audio.