The BNC connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable.
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 converts between a balanced signal and an unbalanced signal. A balun can take many forms and may include devices that also transform impedances but need not do so. Transformer baluns can also be used to connect lines of differing impedance. 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 ignoring, common mode signals.
A helical antenna is an antenna consisting of one or more conducting wires wound in the form of a helix. A helical antenna made of one helical wire, the most common type, is called monofilar, while antennas with two or four wires in a helix are called bifilar, or quadrifilar, respectively.
The F connector is a coaxial RF connector commonly used for "over the air" terrestrial television, cable television and universally for satellite television and cable modems, usually with RG-6/U cable or with RG-59/U cable.
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+).
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 DC to 10 GHz. Male SMC connectors have a socket for the center contact, and Female SMC connectors have a pin for the center contact. SMC jack connectors have an external thread while SMC plug connectors have the mating hex nut. 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.
RG-58/U is a type of coaxial cable often used for low-power signal and RF connections. The cable has a characteristic impedance of either 50 or 52 Ω. "RG" was originally a unit indicator for bulk RF cable in the U.S. military's Joint Electronics Type Designation System. There are several versions covering the differences in core material and shield.
Most countries' amateur radio licences allow licensed operators to install and use radio transmission equipment while at sea. Such operation is known as maritime mobile amateur radio. In most cases the operator's call sign needs to be extended by adding the suffix "/MM" when transmitting at sea.
The Belling-Lee connector is commonly used in Europe and Australia to connect coaxial cables with each other and with terrestrial VHF/UHF roof antennas, antenna signal amplifiers, CATV distribution equipment, TV sets, and FM and DAB radio receivers. In these countries, it is known colloquially as a PAL antenna connector, IEC antenna connector, or simply as a TV aerial plug. It is one of the oldest coaxial connectors still commonly used in consumer devices. For television signals, the convention is that the source has a male connector and the receptor has a female connector. For FM radio signals, the convention is that the source has a female connector and the receptor has a male connector. This is more or less universally adopted with TV signals, while it's not uncommon for FM radio receivers to deviate from this, especially FM radio receivers from companies not based in the areas that use this kind of connector.
A braid-breaker is a filter that prevents television interference (TVI). In many cases, TVI is caused by a high field strength of a nearby high frequency (HF) transmitter, the aerial down lead plugged into the back of the TV acts as a longwire antenna or as a simple vertical element. The radio frequency (RF) current flowing through the tuner of the TV tends to generate harmonics which then spoil the viewing.
An EMC problem occurs when one piece of electronic equipment or an electromagnetic system is adversely affected by the operation of another. One example might be breakthrough by the high field strengths produced by a nearby radio transmitter. EMC problems are not always due to defects in the transmitter, and so do not necessarily require improvements in the radio transmitter design, such as reducing its radiated harmonics. It may be that the immunity of the affected equipment is poor due to inadequate shielding, or filtering of sensitive inputs. EMC problems can have a range of effects on equipment, and there are ways to mitigate or eliminate them in practice. Effective EMC mitigation techniques may differ by the type of equipment that malfunctions, and by the nature of the strong radio frequency field.
The GR connector, officially 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 widely used on General Radio's electronic test equipment and some Tektronix instruments from the 1950s to the 1970s.
The Yaesu FT-817 is one of the smallest MF/HF/VHF/UHF multimode general-coverage amateur radio transceivers. The set is built by the Japanese Vertex Standard Corporation and is sold under the Yaesu brand. With internal battery pack, on board keyer, its all mode/all band capability and flexible antenna, the set is particularly well suited for portable use. The FT-817 is based on a similar circuit architecture as Yaesu's FT-857 and FT-897, so it is a compromise transceiver and incorporates its features to its low price.
The 7-16 DIN connector or 7/16 is a 50 Ω threaded RF connector used to join coaxial cables. It is among the most widely used high power RF connectors in cellular network antenna systems. Originally popular in Europe, it has gained widespread use in the US and elsewhere. It is not to be confused with the similar-sounding EIA flange adaptors which are referred to by the outer diameter in fractions of an inch. The 7–16 DIN connector is also defined by an international standard, IEC 61169-4. It out performs other non-flange options, such as N connectors or BNC connectors, when it comes to interference and intermodulation rejection or higher power handling at RF frequencies.
The Yaesu FT-818 is one of a long line of FT-Series compact transceivers - the range of variations of the FT-Series 'ultra compacts' includes dual band multimode (VHF/UHF) through to the most recent variant, the FT-818ND, which is a MF/HF/VHF/UHF multimode general-coverage receiver & amateur radio transceiver. The set is built by the Japanese Yaesu Musen Co., Ltd. and was first available in March 2018. Whilst it may not be the smallest any more, in terms of what is essentially an old-school pure analogue design PLL synthesised conventional control arrangement transceiver, as opposed to most similar and more recent designs being mostly SDR aka software-defined radio transceiver types which are primarily digital circuitry and technology based, it is still essentially a very compact and very small true portable which is, as many owners of it & the 817 predecessor will confirm, literally as suited to man-pack type usage as easily as used shoulder slung as usable as a QRP transceiver transportable or simply as a base station QRP unit. Incorporating battery powered use via an internal nickel metal hydride type rechargeable battery pack & a substitutable AA type alkaline battery holder, an on board keyer facility, the essentially (and fairly comprehensively when 'wide banded' fully, all analogue mode/all band Rx capability and in 'wide banded' form, close to Tx capable on almost every selectable band it supports, and a supplied tri-band three part flexible helical type antenna, the set is by general design particularly well suited for portable use and QRP use in general. The radio comes with the AA cell holder fitted from the factory, with the nickel hydride rechargeable pack reconfiguration a case of extracting the AA holder and unplugging it then plugging in and fitting the nickel hydride pack - no requirement to change any settings on the radio or move jumpers etc.
