|The mark RG/U is based on USA Military
Standard which is the first complete standardization of radio-frequency cables thus being
accepted and approved in the world although international standardization (IEC) still
RG/U cables are used in a wide range of commercial electronics and highfrequency technique, i.e. where required as follows:
- long duration period
- permanent working temperatures
- high resistivity to jacket abrasion and chemical influences
- high flexibility
- small attenuation
- high stability of characteristic impendance - application of standardized connectors.
The construction, material and tolerances of inner conductor are the elements which determinate mechanical and electrical characteristics of the cable The inner conductor may be tinned or sliver plated. Cables with inner conductor in form of strand have considerably higher flexibility.
In order to increase mechanical strength, the copperweld wires are used.
Temperature conditions, attenuation, dielectrical strenght and flexibility determine the material and construction of cable insulation.
Polyethylene (PE) is mainly used due to its good mechanical and electrical characteristics.
Teflon (F) is the material of a special quality referred to resistivity to high temperatures as well as good electrical characteristics.
The outer conductor is a braid made of bare, silver-plated or tinned copper wire. The construction, covering and screening are defined by MIL-C-17 standard. Cables where considerably higher screening effect is requested are made with double braid.
Cable jacket is classified according to MILC-C-17 standard into quality groups. Jacketing materials without plastyfiers or with some other additives are highly resistant to aging, i.e. the increase of atenuation due to aging is irrelevant.
TYPE OF CABLE JACKETS ACCORDING TO MIL-C-17