This study has come about because I wanted to understand what I was doing with my NanoVNA and how different coax cables where affected with different frequencies:
RG and UR coax cable references
Over the years systems developed whereby standard number systems. This enabled coax made by different manufacturers to conform to the same standard.
Over the years two basic systems evolved for defining RF cables.
1. One originated in the United Kingdom and its type numbers all start with UR.
2. The other system is American with type numbers commencing with the letters RG.
- UK UR system for coax cable types: The UR system as defined in the UK and is still widely used for coaxial cable. UR standard for Uniradio, and later the URM series stands for Uniradio Metric.
- USA RG systems for coax cable types: 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 However it should be noted that the RG specifications are no longer maintained so there is no complete guarantee to the exact specification for the particular type of coax cable
Properties of Popular Coaxial Cables
Note that attenuation values are given at 400 MHz, but can - and do - often have significantly different values at other frequencies. Always check with a coaxial cable vendor for values specific to the type you plan to use.
| Type (/U) | MIL-C-17 | Z0(Ω) | Dielectric Type |
Capacitance (pF/ft) |
O.D. (in.) |
dB/100 ft @400 MHz |
Vmax (rms) |
Shield |
| LMR-100A | 50.0 | FE | 31 | 0.110 | 14 | 2,000 | Braid+Foil | |
| LMR-195 | 50.0 | FE | 25 | 0.195 | 7.0 | 3,000 | Braid+Foil | |
| LMR-200 | 50.0 | FE | 24 | 0.195 | 6.5 | 3,000 | Braid+Foil | |
| LMR-300 | 50.0 | FE | 24 | 0.300 | 4.0 | 5,000 | Braid+Foil | |
| LMR-400 | 50.0 | FE | 24 | 0.405 | 2.5 | 8,000 | Braid+Foil | |
| LMR-500 | 50.0 | FE | 24 | 0.500 | 2.0 | 8,000 | Braid+Foil | |
| LMR-600 | 50.0 | FE | 23 | 0.590 | 1.6 | 8,000 | Braid+Foil | |
| LMR-900 | 50.0 | FE | 23 | 0.870 | 1.1 | 8,000 | Braid+Foil | |
| LMR-1200 | 50.0 | FE | 23 | 1.200 | 0.8 | 8,000 | Braid+Foil | |
| RG-4 | 50.0 | PE | 31 | 0.226 | 11.7 | 1,900 | Braid | |
| RG-5 | 52.5 | PE | 29 | 0.332 | 7.0 | 3,000 | Braid | |
| RG-5A/B | 50.0 | PE | 31 | 0.328 | 6.5 | 3,000 | Braid | |
| RG-6 | /2-RG6 | 76.0 | PE | 20 | 0.332 | 7.4 | 2,700 | Braid |
| RG-6A | /2-RG6 | 75.0 | PE | 21 | 0.332 | 6.5 | 2,700 | Braid |
| RG-8 | 52.0 | PE | 30 | 0.405 | 6.0 | 4,000 | Braid | |
| 9914 (RG-8) | 50.0 | PE | 25 | 0.403 | 2.6 | 300 | Braid+Foil | |
| RG-8A | 52.0 | PE | 30 | 0.405 | 4.5 | 5,000 | Braid | |
| RG-8X | 50.0 | PE | 26 | 0.242 | 8.0 | 2,500 | Braid | |
| RG-9 | 51.0 | PE | 30 | 0.420 | 5.9 | 4,000 | Braid | |
| RG-9A | 51.0 | PE | 30 | 0.420 | 6.1 | 4,000 | Braid | |
| RG-9B | 50.0 | PE | 31 | 0.420 | 6.1 | 5,000 | Braid | |
| RG-10 | 52.0 | PE | 30 | 0.463 | 6.0 | 4,000 | Braid | |
| RG-10A | 52.0 | PE | 30 | 0.463 | 6.0 | 5,000 | Braid | |
| RG-11 | /6-RG11 | 75.0 | PE | 21 | 0.405 | 5.7 | 4,000 | Braid |
| RG-11A | /6-RG11 | 75.0 | PE | 21 | 0.405 | 5.2 | 5,000 | Braid |
| RG-12 | /6-RG12 | 75.0 | PE | 21 | 0.463 | 5.7 | 4,000 | Braid |
| RG-12A | /6-RG12 | 75.0 | PE | 21 | 0.463 | 5.2 | 5,000 | Braid |
| RG-17A | 52.0 | PE | 30 | 0.870 | 2.8 | 11,000 | Braid | |
| RG-22 | /15-RG22 | 95.0 | PE | 16 | 0.405 | 10.5 | 1,000 | Braid |
| RG-22A/B | /15-RG22 | 95.0 | PE | 16 | 0.420 | 10.5 | 1,000 | Braid |
| RG-23/A | /16-RG23 | 125.0 | PE | 12 | 0.650 | 5.2 | 3,000 | Braid |
| RG-24/A | /16-RG24 | 125.0 | PE | 12 | 0.708 | 5.2 | 3,000 | Braid |
| RG-34 | /24-RG34 | 71.0 | PE | 22 | 0.625 | 5.3 | 5,200 | Braid |
| RG-34A | /24-RG34 | 75.0 | PE | 21 | 0.630 | 5.3 | 6,500 | Braid |
| RG-35 | /64-RG35 | 71.0 | PE | 22 | 0.928 | 2.8 | 10,000 | Braid |
| RG-35A/B | /64-RG35 | 75.0 | PE | 21 | 0.928 | 2.8 | 10,000 | Braid |
| RG-54 | 58.0 | PE | 26 | 0.245 | 3,000 | Braid | ||
| RG-55B | 53.5 | PE | 29 | 0.200 | 11.7 | 1,900 | Braid | |
| RG-58 | /28-RG58 | 53.5 | PE | 29 | 0.195 | 11.7 | 1,900 | Braid |
| RG-58A | /28-RG58 | 52.0 | PE | 30 | 0.195 | 13.2 | 1,900 | Braid |
| RG-58B | 53.5 | PE | 28 | 0.195 | 14.0 | 1,900 | Braid | |
| RG-58C | /28-RG58 | 50.0 | PE | 31 | 0.195 | 14.0 | 1,900 | Braid |
| RG-59/A | /29-RG59 | 73.0 | PE | 21 | 0.242 | 10.5 | 2,300 | Braid |
| RG-59B | /29-RG59 | 75.0 | PE | 21 | 0.242 | 9.0 | 2,300 | Braid |
| RG-62/A/B | /30-RG62 | 93.0 | ASP | 14 | 0.242 | 8.0 | 750 | Braid |
| RG-63/A/B | /31-RG63 | 125.0 | ASP | 10 | 0.405 | 5.5 | 1,000 | Braid |
| RG-65/A | /34-RG65 | 950.0 | ASP | 44 | 0.405 | 16 @5MHz | 1,000 | Braid |
| RG-71/A/B | /90-RG71 | 93.0 | ASP | 14 | 0.245 | 8.0 | 750 | Braid |
| RG-79/A/B | /31-RG79 | 125.0 | ASP | 10 | 0.436 | 5.5 | 1,000 | Braid |
| RG-83 | 35.0 | PE | 44 | 0.405 | 9.0 | 2,000 | Braid | |
| RG-88 | 48.0 | 50 | 0.515 | 0.7 @1MHz | 10,000 | Braid | ||
| RG-108/A | /45-RG108 | 78.0 | PE | 20 | 0.235 | 2.8 @10MHz | 1,000 | Braid |
| RG-111/A | /15-RG111 | 95.0 | PE | 16 | 0.478 | 10.5 | 1,000 | Braid |
| RG-114/A | /47-RG114 | 185.0 | ASP | 7 | 0.405 | 8.5 | 1,000 | Braid |
| RG-119 | /52-RG119 | 50.0 | ST | 30 | 0.465 | 3.8 | 6,000 | Braid |
| RG-120 | /52-RG120 | 50.0 | ST | 30 | 0.523 | 3.8 | 6,000 | Braid |
| RG-122 | /54-RG122 | 50.0 | PE | 31 | 0.160 | 18.0 | 1,900 | Braid |
| RG-130 | /56-RG130 | 95.0 | PE | 17 | 0.625 | 8.8 | 3,000 | Braid |
| RG-131 | /56-RG131 | 95.0 | PE | 17 | 0.683 | 8.8 | 3,000 | Braid |
| RG-133/A | /100-RG133 | 95.0 | PE | 16 | 0.405 | 5.7 | 4,000 | Braid |
| RG-141/A | 50.0 | ST | 29 | 0.190 | 9.0 | 1,900 | Braid | |
| RG-142/A/B | /60-RG142 | 50.0 | ST | 29 | 0.195 | 9.0 | 1,900 | Braid |
| RG-144 | /62-RG144 | 75.0 | ST | 20 | 0.410 | 4.5 | 5,000 | Braid |
| RG-164 | /64-RG164 | 75.0 | PE | 21 | 0.870 | 2.8 | 10,000 | Braid |
| RG-165 | /65-RG165 | 50.0 | ST | 29 | 0.410 | 5.0 | 5,000 | Braid |
| RG-166 | /65-RG166 | 50.0 | ST | 29 | 0.460 | 5.0 | 5,000 | Braid |
| RG-174 | 50.0 | 31 | 0.110 | 14.7 | Braid | |||
| RG-177 | /67-RG177 | 50.0 | PE | 31 | 0.895 | 2.8 | 11,000 | Braid |
| RG-178/A/B | /93-RG178 | 50.0 | ST | 29 | 0.072 | 29.0 | 1,000 | Braid |
| RG-179 | /94-RG179 | 70.0 | ST | 21 | 0.100 | 21.0 | 1,200 | Braid |
| RG-179A/B | /94-RG179 | 75.0 | ST | 20 | 0.100 | 21.0 | 1,200 | Braid |
| RG-180 | /95-RG180 | 93.0 | ST | 15 | 0.140 | 17.0 | 1,500 | Braid |
| RG-180A/B | /95-RG180 | 95.0 | ST | 15 | 0.140 | 17.0 | 1,500 | Braid |
| RG-210 | /97-RG210 | 93.0 | ASP | 14 | 0.242 | 8.0 | 750 | Braid |
| RG-211/A | /72-RG211 | 50.0 | ST | 29 | 0.730 | 2.3 | 7,000 | Braid |
| RG-212 | /73-RG212 | 50.0 | PE | 29 | 0.332 | 6.5 | 3,000 | Braid |
| RG-213 | /74-RG213 | 50.0 | PE | 31 | 0.405 | 5.5 | 5,000 | Braid |
| RG-214 | /75-RG214 | 50.0 | PE | 31 | 0.425 | 5.5 | 5,000 | Dbl Braid |
| RG-215 | /74-RG215 | 50.0 | PE | 31 | 0.463 | 5.5 | 5,000 | Braid |
| RG-216 | /77-RG216 | 75.0 | PE | 21 | 0.425 | 5.2 | 5,000 | Braid |
| RG-217 | /78-RG217 | 50.0 | PE | 31 | 0.545 | 4.3 | 7,000 | Braid |
| RG-218 | /79-RG218 | 50.0 | PE | 31 | 0.870 | 2.5 | 11,000 | Braid |
| RG-219 | /79-RG219 | 50.0 | PE | 31 | 0.928 | 2.5 | 11,000 | Braid |
| RG-223 | /84-RG223 | 50.0 | PE | 12 | 0.211 | 8.8 | 1,900 | Dbl Braid |
| RG-302 | /110-RG302 | 75.0 | ST | 20 | 0.201 | 8.0 | 2,300 | Braid |
| RG-303 | /111-RG303 | 50.0 | ST | 29 | 0.170 | 9.0 | 1,900 | Braid |
| RG-304 | /112-RG304 | 50.0 | ST | 29 | 0.280 | 6.0 | 3,000 | Braid |
| RG-307/A | /116-RG307 | 75.0 | 80 | 17 | 0.270 | 7.5 | 1,000 | Braid |
| RG-316 | /113-RG316 | 50.0 | ST | 29 | 0.102 | 20.0 | 1,200 | Braid |
| RG-391 | /126-RG391 | 72.0 | 23 | 0.405 | 15.0 | 5,000 | Braid | |
| RG-392 | /126-RG392 | 72.0 | 23 | 0.475 | 15.0 | 5,000 | Braid | |
| RG-393 | /127-RG393 | 50.0 | ST | 29 | 0.390 | 5.0 | 5,000 | Braid |
| RG-400 | /128-RG400 | 50.0 | ST | 29 | 0.195 | 9.6 | 1,900 | Braid |
| RG-401 | /129-RG401 | 50.0 | ST | 29 | 0.250 | 4.6 | 3,000 | Cu. S-R |
| RG-402 | /130-RG402 | 50.0 | ST | 29 | 0.141 | 7.2 | 2,500 | Cu. S-R |
| RG-403 | /131-RG403 | 50.0 | ST | 29 | 0.116 | 29.0 | 2,500 | Braid |
| RG-405 | /133-RG405 | 50.0 | ST | 29 | 0.086 | 13.0 | 1,500 | Cu. S-R |
| Coax Type | Characteristic impedance | Outside diameter | Velocity factor | Atten @ 100 MHz | Atten @ 1000 MHz | Comments |
| UR43 / URM43 | 50 | 5 | 0.66 | 1.3 | 4.46 | Plain copper wire braid |
| UR57 / URM57 | 75 | 10.3 | 0.66 | 0.63 | 2.3 | Similar to RG11A/U – plain copper wire braid. |
| UR67 / URM67 | 50 | 10.3 | 0.66 | 0.66 | 2.52 | Similar to RG213/U – plain copper wire braid |
| UR74 / URM74 | 50 | 22.1 | 0.66 | 0.33 | 1.4 | Plain copper wire braid |
| UR76 / URM76 | 51 | 5 | 0.66 | 1.7 | 7.3 | Similar to RG58C/U, plain copper wire braid |
| 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 |
| URM91 | 50 | 11.0 | 0.66 | | | Double plain copper wire braid |
- RG stands for Radio Guide.
- U stands for Universal
| Properties of Coaxial Cable Dielectrics(c = speed of light in a vacuum) | ||
|---|---|---|
| Dielectric Type | Time Delay(ns/ft) | Propagation Velocity |
| Solid Polyethylene (PE) | 1.54 | 0.659c |
| Foam Polyethylene (FE) | 1.27 | 0.800c |
| Foam Polystyrene (FS) | 1.12 | 0.910c |
| Air Space Polyethylene (ASP) | 1.15-1.21 | 0.840c-0.880c |
| Solid Teflon (ST) | 1.46 | 0.694c |
| Air Space Teflon (AST) | 1.13-1.20 | 0.850c-0.900c |
Capacitor Dielectrics & Descriptions
Here are few of the most commonly used dielectric materials for capacitors. A brief description and application examples are provide for many.
- Air-Gap:
- Low dielectric loss and offers good cooling. Large-valued tunable capacitors (like in old radios) are often made this way.
- Aluminum:
- Very high capacitance density (capacitance to volume). High dielectric leakage - prone to exploding.
- Ceramic:
- Ceramic dielectric types are differentiated by the temperature coefficient of capacitance, and the dielectric
loss. Available in 1% tolerance for values up to about 1 µF, typically made from Lead zirconate titanate (PZT)
ferroelectric ceramic. Capacitance can change with applied voltage (piezoelectric effect)
- C0G or NP0 (negative-positive-zero, ±0): Typically 4.7 pF to 0.047 µF, 5%. High tolerance and temperature performance (flat over temp). Larger and more expensive. Lowest losses, used in filters, as timing elements, and for balancing crystal oscillators.
- X7R: Typical 3300 pF to 0.33 µF, 10%. Good for non-critical coupling, timing applications. Subject to microphonics.
- Z5U or 2E6: Typical 0.01 µF to 2.2 µF, 20%. Good for bypass, coupling applications. Low price and small size. Subject to microphonics.
- Ceramic dielectric types are differentiated by the temperature coefficient of capacitance, and the dielectric
loss. Available in 1% tolerance for values up to about 1 µF, typically made from Lead zirconate titanate (PZT)
ferroelectric ceramic. Capacitance can change with applied voltage (piezoelectric effect)
- Combination Film:
- Combination polyester (Mylar) and polypropylene. Extremely low temperature coefficient in the 0° C to 85° C temperature range. Volumetric efficiency similar to polycarbonate.
- Glass:
- Extremely stable & reliable
- Kapton Film:
- Electrical properties similar to Mylar with a much higher operating temperature going up to 250° C. A higher cost than Mylar.
- KF (Polymer) Film:
- Extremely high volumetric efficiency with about 4x the "K Factor" of Mylar, making it about 1/4 the size. Higher DF and lower IR are its disadvantages along with cost.
- Mica:
- Chemically inert nature means it does not change physically or chemically with age and it has good temperature stability. Plain mica can absorb moisture, but metallized mica and silver mica are more resistant to moisture.
- Paper Film:
- Paper or Kraft Paper is the oldest of the film capacitor dielectrics. The paper must be impregnated with Epoxy, Wax, Oil, or other suitable impregnate. It is still popular for high voltage and AC rated capacitors operating at lower frequencies. Paper is also wound with plastic dielectrics in combination dielectric capacitors. Its hydroscopic nature allows moisture to degrade performance over time.
- Polyamide (plastic film):
- Operating temperatures of up to 200ºC. High insulation resistance, good stability and a low dissipation factor. High cost and large size.
- Polycarbonate Film:
- Lower DF, higher IR, better temperature coefficient and better stability than Mylar with a slightly lower volumetric efficiency. 2nd most popular dielectric. Polycarbonate capacitors have a 100% voltage rating from -55° C to +125° C.
- Polyester (Mylar) Film:
- A good general purpose plastic dielectric with relativity low cost and high volumetric efficiency. The most popular of the capacitor dielectrics.
- Polypropylene Film:
- Very good temperature coefficient high IR, and low DF make it suitable for AC operation. Usable to 105° C without derating. Popular for AC applications.
- Polystyrene Film:
- Very good electrical properties and excellent stability are its advantages. The big disadvantage is its operation is limited to below 85° C, and their large size.
- Polysulfone Film:
- Electrical properties similar to polycarbonate with a very good temperature coefficient and higher operating temperature. Very limited availability in the last few years has limited its use.
- Tantalum:
- Large capacitance to volume ratio, smaller size, good stability, wide operating temperature range, long reliable operating life. Widely used in miniaturized equipment and computers. Available in both polarized and unpolarized versions, so suitable for AC and DC. Solid tantalums have much better characteristics than wet slug (not permitted in any Mil-Spec equipment) versions.
- Teflon Film:
- The best electrical properties of all the dielectrics. Extremely high IR, low DF and operation to 250° C. Expensive and physically large.
