EIA RF Connectors
EIA RF Connectors are used to connect two items of high power radio frequency rigid or semi-rigid coaxial transmission line. These are only required in high power transmitting installations where the feedline diameters may be several inches. One side of the connection is denoted as a male connection, or bullet, while the other side is denoted as the female connection, or cup; the EIA under the Electronic Components Industry Association, are responsible for a number of standard imperial connector sizes. The flange design and outer conductor dimensions are standardized, by EIA, in the RS-225, 50 Ω, RS-259, 75 Ω, standards, they are referred to by the outer diameter of the outer conductor in fractional inches. Sizes covered under these two standards range from 3/8 to 6 1/8 inch outside diameter for 50 Ω and 3/8 to 3 1/8 inch OD for 75 Ω. Peak pulse power handling, driven by voltage breakdown, is more or less frequency independent for any given size, but the average power, limited by losses heating the centre conductors, increases with the square root of the operating frequency.
The limit is quoted as that dissipation that will raise the inner temperature to 100 °C when the outer is maintained constant at +40 °C. Field failures can occur at power levels well below this if the central bullet connections are not making uniform positive contact and free of contamination. Conversely the average power ratings can be exceeded if there is forced air flow either through the inner conductor or through the void between the inner and outer conductors. Many years ago, the two RS standards were considered obsolete by EIA. Only there has been an effort by manufacturers in the US to update these standards; the corresponding International standards are published by the International Electrotechnical Commission: IEC 60339-1 and IEC 60339-2. These standards are more complete as they include many additional sizes that are missing in the EIA standards. Many of these sizes are interchangeable with RF Connectors defined by the US military in MIL-DTL-24044. Dielectric Exir Broadcasting Radio Frequency Systems Alan Dick Andrew Shively Labs JACAL conectores coaxil Myat Industries Electronics Research SPINNER GmbH SIRA srl SILEX SYSTEM TELECOM
An RCA connector, sometimes called a phono connector or Cinch connector, is a type of electrical connector used to carry audio and video signals. The name RCA derives from the Radio Corporation of America, which introduced the design by the early 1940s for internal connection of the pickup to the chassis in home radio-phonograph consoles, it was a low-cost, simple design, intended only for mating and disconnection when servicing the console. Refinement came with designs, although they remained compatible. RCA connectors began to replace the older quarter-inch phone connectors for many other applications in the consumer audio world when component high-fidelity systems started becoming popular in the 1950s. However, quarter-inch phone connectors are still common in professional audio, while miniature phone connectors predominated in personal stereo systems; the connection's plug is called an RCA plug or phono plug, for "phonograph." The name "phono plug" is sometimes confused with a "phone plug" which may refer to a quarter-inch "phone plug" – Tip/Sleeve or Tip/Ring/Sleeve connector – or to a 4P4C connector used for a telephone.
The word phono in phono connector is an abbreviation of the word phonograph, because this connector was created to allow the connection of a phonograph turntable to a radio receiver, using the radio as an amplifier. This setup was present in most radios manufactured in the 1930s onward by the Radio Corporation of America, who marketed a special turntable for 45 RPM records, the model 9JY. A phono input is a set of input jacks RCA jacks, located on the rear panel of a preamp, mixer or amplifier on early radio sets, to which a phonograph or turntable is attached. Modern styli and phono cartridges give a low level output signal of the order of a few millivolts which the circuitry amplifies and equalizes. Phonograph recordings are made with high frequencies boosted and the low frequencies attenuated: during playback the frequency response changes are reversed; this reduces background noise, including clicks or pops, conserves the amount of physical space needed for each groove, by reducing the size of the larger low-frequency undulations.
This is accomplished in the amplifier with a phono input that incorporates standardized RIAA equalization circuitry. Through at least the 1980s, the phono input was available on consumer stereo equipment—even some larger boomboxes had them. By the 2000s only sophisticated and expensive stereo receivers retained the phono input, since most users were expected to use digital music formats such as CD or satellite radio; some newer low-cost turntables include built-in amplifiers to produce line-level outputs. Nearly all DJ mixers have two or more phono inputs, together with two or more one-volt line inputs that use RCA connectors; this "phono input" designed for the millivolt signal from an unamplified turntable should not be confused with the modern standard one-volt line input and output that uses RCA connectors and is found on video cameras and similar modern equipment. In the most normal use, cables have a standard plug on each end, consisting of a central male connector, surrounded by a ring.
The ring is segmented to provide spring gripping pressure when mated. Devices mount the socket; the ring is larger in diameter and longer than the ring on the plug, allowing the plug's ring to fit over it. The jack has a small area between the outer and inner rings, filled with an insulator plastic; the connector was used for audio signals. As with many other connectors, the RCA has been adopted for other uses than intended, including as a DC power connector, an RF connector, as a connector for loudspeaker cables, its use as a connector for composite video signals is common, but provides poor impedance matching. RCA connectors and cable are commonly used to carry S/PDIF-formatted digital audio, with plugs colored orange to differentiate them from other typical connections. Connections are made by pushing the cable's plug into the female jack on the device; the signal-carrying pin protrudes from the plug, comes into contact with the socket before the grounded rings meet, resulting in loud hum or buzz if the audio components do not share a common ground and are powered while making connections.
Continuous noise can occur if the plug falls out of the jack, breaking the ground connection but not the signal. Some variants of the plug cheaper versions give poor grip and contact between the ground sheaths due to their lack of spring action, they are color-coded, yellow for composite video, red for the right audio channel, white or black for the left channel of stereo audio. This trio of jacks can be found on the back of all audio and video equipment. One or more sets are found on TV sets to facilitate connection of camcorders, other portable video sources and video game consoles. Although nearly all connectors, including analog and S/PDIF audio as well as composite and component video, can use identical 75 Ω cables, sales of special-purpose cables for each use have proliferated. Varying cable quality means that a cheap line-level audio cable might not transfer component video. For digital audio, as long as a connection is made using the cabl
MCX are coaxial RF connectors developed in the 1980s. They are 30 % smaller. MCX is standardized in European CECC 22220. MCX connectors use a snap-on interface and have a 50 Ω impedance, they offer broadband capability from DC to 6 GHz. The contact surfaces are gold-plated; the outer diameter of the plug is 0.140 inch. This type of connector is used on the Apple Airport Extreme Base Station's external antenna port and requires an adapter for most antennas. MCX and the smaller MMCX connector are used to connect external antennas to GPS receivers, they are common on USB DVB-T tuners for computers and laptops, to connect an external antenna to the tuner. MMCX connector TNC connector SMA connector F connector
A spring is an elastic object that stores mechanical energy. Springs are made of spring steel. There are many spring designs. In everyday use, the term refers to coil springs; when a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force proportional to its change in length. The rate or spring constant of a spring is the change in the force it exerts, divided by the change in deflection of the spring; that is, it is the gradient of the force versus deflection curve. An extension or compression spring's rate is expressed in units of force divided by distance, for example or N/m or lbf/in. A torsion spring is a spring. A torsion spring's rate is in units of torque divided by angle, such as N · ft · lbf/degree; the inverse of spring rate is compliance, that is: if a spring has a rate of 10 N/mm, it has a compliance of 0.1 mm/N. The stiffness of springs in parallel is additive. Springs are made from a variety of the most common being spring steel.
Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication. Some non-ferrous metals are used including phosphor bronze and titanium for parts requiring corrosion resistance and beryllium copper for springs carrying electrical current. Simple non-coiled springs were used throughout human history. In the Bronze Age more sophisticated spring devices were used, as shown by the spread of tweezers in many cultures. Ctesibius of Alexandria developed a method for making bronze with spring-like characteristics by producing an alloy of bronze with an increased proportion of tin, hardening it by hammering after it was cast. Coiled springs appeared early in door locks; the first spring powered-clocks appeared in that century and evolved into the first large watches by the 16th century. In 1676 British physicist Robert Hooke postulated Hooke's law, which states that the force a spring exerts is proportional to its extension. Springs can be classified depending on how the load force is applied to them: Tension/extension spring – the spring is designed to operate with a tension load, so the spring stretches as the load is applied to it.
Compression spring – is designed to operate with a compression load, so the spring gets shorter as the load is applied to it. Torsion spring – unlike the above types in which the load is an axial force, the load applied to a torsion spring is a torque or twisting force, the end of the spring rotates through an angle as the load is applied. Constant spring – supported load remains the same throughout deflection cycle Variable spring – resistance of the coil to load varies during compression Variable stiffness spring – resistance of the coil to load can be dynamically varied for example by the control system,some types of these springs vary their length thereby providing actuation capability as well They can be classified based on their shape: Flat spring – this type is made of a flat spring steel. Machined spring – this type of spring is manufactured by machining bar stock with a lathe and/or milling operation rather than a coiling operation. Since it is machined, the spring may incorporate features in addition to the elastic element.
Machined springs can be made in the typical load cases of compression/extension, etc. Serpentine spring – a zig-zag of thick wire – used in modern upholstery/furniture. Garter spring - A coiled steel spring, connected at each end to create a circular shape; the most common types of spring are: Cantilever spring – a spring fixed only at one end. Coil spring or helical spring – a spring is of two types: Tension or extension springs are designed to become longer under load, their turns are touching in the unloaded position, they have a hook, eye or some other means of attachment at each end. Compression springs are designed to become shorter, their turns are not touching in the unloaded position, they need no attachment points. Hollow tubing springs can be either extension springs or compression springs. Hollow tubing is filled with oil and the means of changing hydrostatic pressure inside the tubing such as a membrane or miniature piston etc. to harden or relax the spring, much like it happens with water pressure inside a garden hose.
Alternatively tubing's cross-section is chosen of a shape that it changes its area when tubing is subjected to torsional deformation – change of the cross-section area translates into change of tubing's inside volume and the flow of oil in/out of the spring that can be controlled by valve thereby controlling stiffness. There are many other designs of springs of hollow tubing which can change stiffness with any desired frequency, change stiffness by a multiple or move like a linear actuator in addition to its spring qualities. Volute spring – a compression coil spring in the form of a cone so that under compression the coils are not forced against each other, thus permitting longer travel. Hairspring or balance spring – a delicate spiral spring used in watches and places where electricity must be carried to rotating devices such as steering wheels without hindering the rotation. Leaf spring – a flat spring used in vehicle suspensions, electrical switches, bows. V-spring – used in antique firearm mechanisms such as the wheellock and percussion cap locks.
Door-lock spring, as
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 is designed for use from DC to 18 GHz, is most used in microwave systems, hand-held radio and mobile telephone antennas, more with WiFi antenna systems and USB software-defined radio dongles, it is commonly used in radio astronomy at higher frequencies. SMA connectors can be visually confused with the standard household 75-ohm type F coax connector, as there is only about a 2 mm difference overall in the specifications. Type F cannot be mated with SMA connectors without the use of an adapter; the SMA name is used for a superficially similar optical fiber connector. The interface dimensions for SMA connectors are listed in MIL-STD-348; the SMA connector employs a 1/4-inch diameter, 36-thread-per-inch threaded barrel. The male is equipped with a hex nut measuring 5/16 inch across opposite flats, thus taking the same wrench as a #6 SAE hex nut.
A standard-polarity SMA male connector has a center pin surrounded by barrel with inside threads, the standard SMA female connector has a center sleeve surrounded by a barrel with outside threads. As with most other connectors, the gender assignment thus corresponds to the innermost electrical component. There are reverse-polarity SMA connectors in which the pin and sleeve are swapped. See below for a fuller description; the SMA connector uses a polytetrafluoroethylene dielectric which will contact along the mating plane. Variability in the construction and the mating of the connectors limits the repeatability of the connector impedance. For that reason and that they are just rated for a limited number of connection cycles, an SMA connector is not a good choice for metrological applications. SMA connectors are rated for up to 500 mating cycles, but to achieve this it is necessary to properly torque the connector when making the connection. A 5/16-inch torque wrench is required for this, set to 3–5 in·lbf for brass, 7–10 in·lbf for stainless steel connectors.
Flats are sometimes provided on the cable side of the connector assembly so that a second wrench can be used to prevent it from rotating and damaging the joint to the cable. It is advisable to inspect and clean out loose debris from the internal surfaces with compressed air or a gas duster can before mating; the SMA connector is rated for mode-free operation from DC to 18 GHz, though some proprietary versions are rated to 26.5 GHz. For performance above this, SMA-like connectors are used; these are the 3.5 mm connector, rated to 34 GHz, the 2.92 mm, good up to 46 GHz. These connectors keep the same outside thread as the SMA, so they can be cross-mated, but the precision connector can be damaged when mating with low-grade SMA connectors; the precision versions use an air dielectric with appropriately scaled center conductors. Beyond 46 GHz, the 2.4 mm, 1.85 mm and 1.0 mm connectors exist. These are similar to the SMA connector, but with the geometries incompatibly scaled; these have mode-free operation to 50, 65, 110 GHz respectively.
Reverse-polarity SMA is a variation of the SMA connector specification which reverses the gender of the interface, as shown in Figures 1 and 2. The term "reverse polarity" here refers only to the gender of the connector's contact pin, not in any way to the signal polarity; the female RP-SMA connector has the same external housing as a standard or conventional female SMA connector, which consists of an outer shell with the threads on the outside. The RP-SMA male has threads on the inside like a conventional male, but has a center receptacle instead of the male pin in the middle. Normal SMA connectors are incompatible with RP-SMA connectors. RP-SMA connectors have been used by Wi-Fi equipment manufacturers to comply with specific national regulations, such as those from the FCC, which are designed to prevent consumers from connecting antennas which exhibit gain and therefore breach compliance. However, by 2000, the FCC regarded the connectors as available, though delaying its ruling indefinitely.
As of 2018, leading manufacturers such as Netgear and Linksys are still using RP-SMA connectors on their Wi-Fi equipment. RF connector SMB connector, SMC connector BNC connector, TNC connector, N connector Coaxial cable Optical fiber connector MMCX connector MCX connector Hirose U. FL Radio-frequency connectors. Part 15: R. F. coaxial connectors with inner diameter of outer conductor 4.13 mm with screw coupling — Characteristic impedance 50 ohms. International Standard IEC 60169-15, 1979. CECC 22110/111 Connectors, electrical, radio frequency. Military specification sheet MIL-C-39012. RF Connector Information by WA1MBA Photo gallery, gender & compatibility Grid of SMA connectors from GetFPV
The GR connector the General Radio Type 874, was a type of RF connector used for connecting coaxial cable. Designed by Eduard Karplus, Harold M. Wilson and William R. Thurston at General Radio Corporation, it was used on General Radio's electronic test equipment and some Tektronix instruments from the 1950s to the 1970s. The connector had several desirable properties: Good control of the electrical impedance across a wide range of frequencies, therefore low reflection Reliable mating Hermaphrodism, so there were no "male" or "female" connectors; this last characteristic was achieved by having both the inner and outer conductors made from four leaves, two of which were displaced outwards and two of which were displaced inwards. By rotating one connector by 90 degrees, its inner leaves would mate with the other connector's outer leaves and vice versa; when mated, the inner leaves were susceptible to breakage due to stubbing and fatigue cracking as the connector was pressed together and alignment was perfected.
In 1961, an optional locking mechanism consisting of an outer hex nut encasing a captured threaded barrel was added to the 874 line. It can be seen in the photograph of a GR-900 to GR-874 adapter; the locking assembly can be backed off the RF connector. The threaded barrel is supplied on each connector; the threaded barrel was withdrawn into the nut on one connector and extended on the other to allow the barrel to engage the nut of both mating connectors. This style of locking mechanism was continued in GR-874's thematic successors. Adapters to other connector series were available; the limited frequency range of a 14 mm connector and its high manufacturing cost overcame its ease of assembly and the GR-874 was supplanted by the 7 mm type N connector and its variants, the BNC connector and the TNC connector, the higher frequency 3.5 mm SMA connectors. General Radio still a major source of RF test equipment, designed the incompatible GR-900 as a 14 mm successor to the GR-874, filling the industry's need for a higher performance sexless connector for reversible lab standards and related test equipment.
The GR-900 was in turn succeeded in this essential niche role by the sexless APC-7 connector
A screw thread shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread. A screw thread is the essential feature of the screw as a simple machine and as a fastener; the mechanical advantage of a screw thread depends on its lead, the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that friction is sufficient to prevent linear motion being converted to rotary, so the screw does not slip when linear force is applied, as long as no external rotational force is present; this characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is comparable to driving a wedge into a gap until it sticks fast through friction and slight elastic deformation. Screw threads have several applications: Fastening: Fasteners such as wood screws, machine screws and bolts.
Connecting threaded hoses to each other and to caps and fixtures. Gear reduction via worm drives Moving objects linearly by converting rotary motion to linear motion, as in the leadscrew of a jack. Measuring by correlating linear motion to rotary motion, as in a micrometer. Both moving objects linearly and measuring the movement, combining the two aforementioned functions, as in a leadscrew of a lathe. In all of these applications, the screw thread has two main functions: It converts rotary motion into linear motion, it prevents linear motion without the corresponding rotation. Every matched pair of threads and internal, can be described as male and female. For example, a screw has male threads; this property is called gender. The helix of a thread can twist in two possible directions, known as handedness. Most threads are oriented so that the threaded item, when seen from a point of view on the axis through the center of the helix, moves away from the viewer when it is turned in a clockwise direction, moves towards the viewer when it is turned counterclockwise.
This is known as a right-handed thread. Threads oriented in the opposite direction are known as left-handed. By common convention, right-handedness is the default handedness for screw threads. Therefore, most threaded parts and fasteners have right-handed threads. Left-handed thread applications include: Where the rotation of a shaft would cause a conventional right-handed nut to loosen rather than to tighten due to applied torque or to fretting induced precession. Examples include: The left hand pedal on a bicycle; the left-hand grinding wheel on a bench grinder. The axle nuts, or less lug nuts on the left side of some automobiles; the securing nut on some circular saw blades – the large torque at startup should tend to tighten the nut. The spindle on brushcutter and line trimmer heads, so that the torque tends to tighten rather than loosen the connection In combination with right-hand threads in turnbuckles and clamping studs. In some gas supply connections to prevent dangerous misconnections, for example: In gas welding the flammable gas supply uses left-handed threads, while the oxygen supply if there is one has a conventional thread The POL valve for LPG cylinders In a situation where neither threaded pipe end can be rotated to tighten or loosen the joint.
In such a case, the coupling will have one left-handed thread. In some instances, for example early ballpoint pens. In mechanisms to give a more intuitive action as: The leadscrew of the cross slide of a lathe to cause the cross slide to move away from the operator when the leadscrew is turned clockwise; the depth of cut screw of a "Bailey" type metal plane for the blade to move in the direction of a regulating right hand finger. Some Edison base lamps and fittings have a left-hand thread to deter theft, since they cannot be used in other light fixtures; the cross-sectional shape of a thread is called its form or threadform. It may be square, trapezoidal, or other shapes; the terms form and threadform sometimes refer to all design aspects taken together. Most triangular threadforms are based on an isosceles triangle; these are called V-threads or vee-threads because of the shape of the letter V. For 60° V-threads, the isosceles triangle is, more equilateral. For buttress threads, the triangle is scalene.
The theoretical triangle is truncated to varying degrees. A V-thread in which there is no truncation is called a sharp V-thread. Truncation occurs for practical reasons—the thread-cutting or thread-forming tool cannot have a sharp point, truncation is desirable anyway, because otherwise: The cutting or forming tool's edge will break too easily; the point of the threadform adds little strength to the thre