{{short description|Type of coaxial cable}} {{Refimprove|date=August 2016}} thumb|A section of RG-59 cable with its end stripped. {{Ordered list|list-style-type=upper-latin |Outer plastic sheath |Copper braid shield |Inner dielectric insulator |Copper-plated core (sometimes solid core) }}

'''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).<ref>{{cite web|url=http://objects.eanixter.com/PD361313.PDF |title=Product Specifications : 8261303/10 & 5571 WHRL RG59 40 1000 |website=Objects.eanixter.com |accessdate=2016-08-03}}</ref> The 75&nbsp;ohm impedance matches a dipole antenna in free space. ''RG'' (for ''radio guide'') 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.

RG-59 is often used at baseband video frequencies, such as composite video. It may also be used for broadcast frequencies, but its high-frequency losses are too high to allow its use over long distances; in these applications, RG-6 or RG-11 are used instead. In cases where the transmission distance is too long for these media, such options as UTP (unshielded twisted pair) or fiber optic can be used.

RG-59 coaxial cable is commonly packed with consumer equipment, such as VCRs or digital cable/satellite receivers. Manufacturers tend to include only RG-59 cables because it costs less than RG-6 does. However, given the short lengths provided (usually {{convert|4|-|6|ft|m|abbr=on|disp=or}}), this is generally sufficient for its typical use.

RG-59 is frequently used to synchronize two digital audio devices, such as ADAT optical devices. This is called word clock.

==See also== * BNC connector * Coaxial cable * RG-58 – A similar cable but with an impedance of 50 or 52 ohms

==References== {{Reflist}}

==Bibliography== * {{cite book |title=The ARRL Handbook for Radio Communications 2006 |publisher=American Radio Relay League |location=Newington, CT |last=Straw |first=Dean |edition=83rd |isbn=0-87259-949-3 |oclc=62026192}}

Category:Signal cables Category:Transmission lines

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