LMR-240 vs RG-58: A Practical Upgrade for Your Antenna Run
LMR-240 and RG-58 are both flexible 50-ohm cables commonly used for antenna connections, but LMR-240 represents a major performance upgrade. RG-58 uses a solid PE dielectric with tinned copper braid — a design from the 1950s. LMR-240 uses modern foamed PE and a bonded foil + braid shield for dramatically lower loss at VHF and UHF frequencies.
The Short Answer
LMR-240 is the right choice for any permanent installation. It costs more per foot but the loss improvement over RG-58 is substantial enough to justify the cost on any run over 10 feet at VHF and above.
Key Differences at a Glance
- LMR-240 loss at 440 MHz: 4.4 dB/100ft vs RG-58's 9.8 dB — less than half the loss
- At 2.4 GHz, LMR-240 loses 10.8 dB/100ft vs RG-58's estimated 25+ dB — critical for WiFi
- LMR-240 has higher power handling: 350W at 150 MHz vs RG-58's 150W
- Both cables are similarly flexible — LMR-240 is only slightly stiffer
- LMR-240 has a UV-resistant jacket; RG-58's PVC jacket degrades in sunlight
Side-by-Side Specifications
| Specification | LMR240 Times | RG58 |
|---|---|---|
| Impedance | 50 Ohm | 50 Ohm |
| Frequency Range | DC – 6 GHz | DC – 1 GHz |
| Velocity Factor | 0.84 | 0.66 |
| Dielectric | Foamed PE | Solid PE |
| Shield | Aluminum foil + tinned copper braid | Tinned copper braid (95%) |
| Jacket | PE | PVC |
| Center Conductor | Bare copper clad aluminum, 1.42mm | Tinned copper, 19×0.18mm |
| Min. Bend Radius | 1.2 in (30mm) | 1.0 in (25mm) |
| Max Voltage | 600 VRMS | 1400 VRMS |
| Temperature Range | -40°C to +85°C | -40°C to +85°C |
| Weight | 2.5 lb/100ft | 2.2 lb/100ft |
Attenuation Comparison (dB per 100 ft)
| Frequency | LMR240 Times | RG58 | Difference |
|---|---|---|---|
| 100 MHz | 2.4 dB | 4.3 dB | +1.9 dB (RG58 worse) |
| 450 MHz | 5.3 dB | 9.8 dB | +4.5 dB (RG58 worse) |
| 900 MHz | 7.5 dB | 14.3 dB | +6.8 dB (RG58 worse) |
| 1.8 GHz | 10.8 dB | 21.5 dB | +10.7 dB (RG58 worse) |
| 2.4 GHz | 12.6 dB | 25.5 dB | +12.9 dB (RG58 worse) |
| 5.8 GHz | 20.6 dB | 44 dB | +23.4 dB (RG58 worse) |
When to Choose Each Cable
Choose LMR240 Times when:
- VHF/UHF antenna runs over 10 ft
- WiFi antenna extensions
- Outdoor permanent installations
- Cellular booster connections
Choose RG58 when:
- Very short jumpers under 6 ft
- Portable and temporary setups
- HF only operation under 15 MHz
- Throwaway/disposable cables
Frequently Asked Questions
Is LMR-240 worth the upgrade from RG-58?
Yes, for nearly any application. The loss reduction is significant at VHF and above, and the UV-resistant jacket makes LMR-240 far more durable outdoors. The price difference is modest compared to the performance gain.
Do LMR-240 and RG-58 use the same connectors?
No — they have different outer diameters (0.240" vs 0.195"). You need connectors sized specifically for each cable.
Build Your LMR240 Times or RG58 Cable
Pick your connectors, choose your length — hand-assembled and shipped free in the USA.