300-ohm ladder line is a type of balanced transmission line often used in amateur radio, television antennas, and some professional RF applications. Below are the typical specifications, power handling, and other details:

Specifications

1. Impedance:
   • 300 ohms (nominal, balanced).
2. Material:
   • The conductors are typically made of copper or copper-clad steel.
   • The insulators are generally made of polyethylene or similar materials.
3. Spacing:
   • The two conductors are held apart by a uniform dielectric spacing, maintaining the 300-ohm impedance.
4. Loss Characteristics:
   • Lower loss than coaxial cable over similar distances, especially at higher frequencies.
   • Loss depends on the quality of the material, frequency, and length.

Power Handling

1. Power Ratings:
   • 300-ohm ladder line can typically handle hundreds of watts of RF power.
   • High-quality ladder line can handle up to 1,000 watts or more, depending on the spacing and insulation material.
2. Factors Influencing Power Handling:
   • Dielectric Breakdown: The insulation must resist high voltages caused by high RF power.
   • Heating: Larger conductor sizes allow for greater current capacity and less heating.

Advantages

• Low Loss: Ladder line has significantly lower loss than coaxial cable, especially at high frequencies, because of its open-air dielectric and balanced design.
• Flexibility: It can be used for long runs with minimal signal degradation.
• Wide Matching Range: Ideal for use with antenna tuners, allowing operation across a wide range of frequencies.

Applications

1. Feeding multi-band dipole or Yagi antennas.
2. Use in amateur radio for high-efficiency transmission.
3. Broadcasting and TV antenna systems.

If you need detailed specifications for a particular manufacturer or application, let me know!