RF Coax cable data and specifications

- an overview along with a table of specifications and data for the more commonly available types of RF coax cable, i.e. RF cable.

There is a variety of different types of coax or coaxial cable that are in widespread use. Different types of coax cable or feeder are needed for different purposes and applications and accordingly it is necessary have specifications and data to be able to determine the required type or RF cable easily.

While it would be possible to manufacture an infinite variety of RF cables, standard varieties are specified. There are two basic systems that are used for defining RF cables. One originated in the United Kingdom and its type numbers all start with UR. The other system is American with type numbers commencing with the letters RG.

The RG series was originally used to specify the types of coax cables for military use, and the specification took the form RG (RG from Radio Guide) plus two numbers. In some instances these numbers were followed by the letter U which indicated it was for multiple uses. These types of coax cable were all listed in the MIL-HDBK-216 which is now obsolete. Although full MIL specifications are now officially used for specifying most components for military use, the RG series of RF cables continued to be used because of its widespread acceptance. However it should be noted that the RG specifications are no longer maintained so there is no complete guarantee to the exact specification for the particular type of coax cable.

A summary of data for some of the more commonly used types of coax or coaxial cable is given below. Most of these RF cables are easily available from RF cable stockists.:

Type	Characteristic impedance	Outside diameter	Velocity factor	Atten @ 100 MHz	Atten @ 1000 MHz	Comments
RG5/U	52.5	8.4	0.66	1.0	3.8
RG6A/U	75	8.4	0.66	1.0	3.7
RG9/U	51.0	10.7	0.66	0.66	2.4
RG10A/U	50	12.1	0.66	0.66	2.6
RG11A/U	75	10.3	0.66	0.76	2.6
RG12A/U	75	12.1	0.66	0.76	2.6
RG20A/U	50	30.4	0.66	0.22	1.2
RG22	95	10.7		0.75	1.5
RG23	125	24.0		0.52	2.0
RG24	125	25.5		0.52	2.0
RG34	75	16.0		0.46	1.8
RG58C/U	50	5.0	0.66	1.8	7.6
RG59B/U	75	6.1	0.66	1.2	4.6
RG62A/U	93	6.1	0.84	0.9	2.8
RG63	125	10.3		0.6	2.1
RG79	125	12.1		0.6	2.1
RG108	78	6.0		1.1	3.8
RG111	95	12.1		0.75	2.6
RG114	185	10.3		1.1	3.8
RG119	50	11.8		0.5	1.8
RG120	50	13.3		0.5	1.8
RG122	50	4.1		1.7	5.5
RG213/U	50	10.3	0.66	0.62	2.6	Polythene dielectric
RG214/U	50	10.8	0.66	0.76	2.9	Double screened, silver plated copper wire
RG223/U	50	5.5	0.66	1.58	5.4
UR43	50	5	0.66	1.3	4.46
UR57	75	10.2	0.66	0.63	2.3	Similar to RG11A/U
UR67	50	10.3	0.66	0.66	2.52	Similar to RG213/U
UR74	51	22.1	0.66	0.33	1.4
UR76	51	5	0.66	1.7	7.3	Similar to RG58C/U
UR77	75	22.1	0.66	0.33	1.4
UR79	50	21.7	0.96	0.17	0.6
UR90	75	6.1	0.66	1.2	4.1	Similar to RG59B/U

Data for attenuation figures are typical figures and measured in dB / 10 metres             dimensions in mm

The RF cables described above are all flexible types. For microwave applications where very low loss is needed, semi rigid coaxial RF cable using a solid copper outer sheath may be used. This type of coax offers superior screening compared to RF cables with a braided outer conductor, especially at microwave frequencies. As the name implies, though, it is not particularly flexible and is not intended to be flexed after it has been formed to the required shape.

This RF cable data has been presented as a guide and no liability can be taken for any errors or mistakes in the data. Naturally every care has been taken to ensure the data concerning these RF cables is correct.