Coaxial Cable Loss Calculator
Calculate signal attenuation for coaxial cables at various frequencies.
Cable Loss Reference (dB/100 ft)
| Cable | 900 MHz | 2.4 GHz | 5.8 GHz |
|---|---|---|---|
| RG-58 | 4.9 | 9.0 | 16.0 |
| RG-213 | 2.0 | 3.7 | 6.5 |
| LMR-400 | 1.1 | 1.9 | 3.5 |
| LMR-600 | 0.7 | 1.3 | 2.3 |
| 7/8" Hardline | 0.3 | 0.54 | 0.95 |
Understanding Cable Loss
Frequency Dependence
Cable loss increases with frequency. A cable that works well at 150 MHz may have excessive loss at 5.8 GHz. Always calculate loss at your operating frequency.
Cable Selection Tips
- Short runs (<25 ft): RG-58, RG-8X acceptable
- Medium runs (25-100 ft): LMR-240, RG-213
- Long runs (>100 ft): LMR-400, LMR-600
- Tower/commercial: Hardline preferred
Loss Budget Guidelines
- Keep total feed line loss under 3 dB when possible
- 3 dB loss = 50% power loss
- 6 dB loss = 75% power loss
- 10 dB loss = 90% power loss
Connector Quality
Use quality connectors matched to your cable. Poor connectors can add significant loss and cause VSWR problems. N-type connectors are preferred for frequencies above 1 GHz.