What Are RG8 Coax Cables?

RG8 coaxial cable is a relatively large diameter, 50-ohm coaxial cable. Its primary applications include broadcasting, amateur radios, and antenna feed cable. It is suitable for radio frequencies up to 4,000 MHz. Signal attenuation at 4,000 MHz is 23 decibels per 100 feet. Attenuation drops sharply at lower frequencies and is 7.4 dB/100ft at 1,000 MHz. RG8 coax has a braided copper shield with a minimum 95% covering that provides good radio frequency shielding. The cable's maximum voltage rating is 4,000 volts.

1 items

  • RG8
    RG 8
    $0.00 / 1000 FT
    • Approx LBS/MFT: 0.00
    • Cond. Material: Bare Copper
    • Conductor Stranding: 7/.0285
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How Is RG8 Coaxial Cable Constructed?


RG8 cable uses a stranded annealed copper inner conductor made up of seven strands of 21 American Gauge Wire (AWG). The diameter of the conductor is approximately 0.0855 inches.


This coaxial cable has a solid polyethylene dielectric with an overall diameter of 0.285 inches. This material has a dielectric constant of 2.3. It has good abrasion resistance and weathering properties.


The outer conductor or shield is a wire braid made from soft annealed copper wire. Braiding cover exceeds 95% for improved shielding.


The coax cable has a protective outer jacket made from polyvinyl chloride (PVC) with an overall diameter of 0.405 inches. 

RG8 Cable Applications

You can use RG8 cables for radio frequency applications up to 4,000 MHz that require a characteristic impedance of 50 ohms and for radio antennas. The cable has good power handling capabilities that range from 180 watts at 1,000 MHz up to 1,200 watts at 50 MHz. Other applications include high-quality audio recording and 10Base5 standard Ethernet connections. 

Similar Cables to RG8 Coaxial

RG8X Coaxial Cable

This is a thinner version of RG8 coax, with an overall diameter of 0.242 inches, that’s commonly used for amateur radio applications. RG8X coaxial is easier to handle because of its increased flexibility, although attenuation figures are approximately double those of standard RG8 and its UL voltage rating is lower at 300 volts.

RG58 Coaxial Cable

RG58 cable has similar characteristics to RG8X coax and is mainly suitable for frequencies below 1,000 MHz. Radio frequency shielding properties are lower than RG8 coaxial, although RG58 cable has similar attenuation properties to RG8X cable. You can use it for 10Base2 Ethernet.

RG213 Coaxial Cable

This is a similar cable to RG8 coaxial cable. Military specification RG213 coaxial cable has better high-frequency properties than RG8, with lower attenuation characteristics and a slightly lower maximum voltage.

LMR400 Coaxial Cable

This low-loss coaxial cable from Times Microwave has similar external dimensions to RG8 but a larger inner conductor and a dual copper braid and aluminum braid shield. LMR400 cable has better RF shielding and significantly lower attenuation than RG8 coaxial cable. 

RG8 Coaxial Cable Specifications

  • Central conductor: Stranded pure copper conductor with a final diameter of 0.0855 inches
  • Dielectric Insulation: Solid polyethylene with an outside diameter of 0.285 inches
  • Outer conductor and shield: Pure copper wire braid
  • Jacket: PVC jacket
  • Nominal impedance: 50 ohms
  • Nominal capacitance: 28.5 picofarads per foot
  • Inner conductor DC resistance: 1.9 ohms/1,000 feet
  • Outer conductor DC resistance: 1.2 ohms/1,000 feet
  • Operating temperature range: 80 degrees Celsius to -40 C
  • Maximum voltage: 4,000 volts DC
  • Attenuation at 1,000 MHz: Approximately 7.4 dB/ft
  • Attenuation at 4,000 MHz: Approximately 23 dB/ft