LMR-400 UltraFlex vs LMR-400: When Do You Need the Flexible Version?
LMR-400 UltraFlex and standard LMR-400 have nearly identical electrical performance, but very different physical handling characteristics. Standard LMR-400 uses a solid aluminum outer conductor that resists bending — once installed, it stays in place. LMR-400 UltraFlex replaces the solid outer with a stranded construction that allows repeated bending without signal degradation.
The Short Answer
Use standard LMR-400 for fixed outdoor installations, direct burial, and tower runs where the cable will not be moved. Use LMR-400 UltraFlex for equipment racks, mobile installs, jumpers that will be repositioned, and anywhere the cable must route around tight corners repeatedly.
Key Differences at a Glance
- LMR-400 UF has a tighter minimum bend radius: 1.0" vs standard LMR-400's 2.0"
- Electrical performance is virtually identical — same loss figures and impedance
- LMR-400 UF costs roughly 20-30% more per foot than standard LMR-400
- Standard LMR-400 has slightly better UV and crush resistance for outdoor use
- Both use the same connector types — connectors for LMR-400 fit UltraFlex as well
Side-by-Side Specifications
| Specification | LMR400 ULTRA FLEX Times | LMR400 Times |
|---|---|---|
| Impedance | 50 Ohm | 50 Ohm |
| Frequency Range | DC – 6 GHz | DC – 6 GHz |
| Velocity Factor | 0.83 | 0.85 |
| Dielectric | Foamed PE | Foamed PE |
| Shield | Aluminum foil + tinned copper braid | Aluminum foil + tinned copper braid |
| Jacket | PVC | PE |
| Center Conductor | Stranded bare copper, 2.74mm | Bare copper clad aluminum, 2.74mm |
| Min. Bend Radius | 1.5 in (38mm) | 2.0 in (50mm) |
| Max Voltage | 600 VRMS | 600 VRMS |
| Temperature Range | -40°C to +85°C | -40°C to +85°C |
| Weight | 5.5 lb/100ft | 5.0 lb/100ft |
Attenuation Comparison (dB per 100 ft)
| Frequency | LMR400 ULTRA FLEX Times | LMR400 Times | Difference |
|---|---|---|---|
| 100 MHz | 1.6 dB | 1.5 dB | -0.1 dB (LMR400 Times worse) |
| 450 MHz | 3.5 dB | 3.3 dB | -0.2 dB (LMR400 Times worse) |
| 900 MHz | 5 dB | 4.7 dB | -0.3 dB (LMR400 Times worse) |
| 1.8 GHz | 7.2 dB | 6.8 dB | -0.4 dB (LMR400 Times worse) |
| 2.4 GHz | 8.4 dB | 7.9 dB | -0.5 dB (LMR400 Times worse) |
| 5.8 GHz | 13.8 dB | 13 dB | -0.8 dB (LMR400 Times worse) |
When to Choose Each Cable
Choose LMR400 ULTRA FLEX Times when:
- Equipment rack jumpers
- Mobile vehicle installations
- Routing around obstacles and corners
- Cables that will be moved or repositioned
Choose LMR400 Times when:
- Fixed outdoor tower runs
- Direct burial installations
- Long straight feedlines
- Maximum UV and weather resistance
Frequently Asked Questions
Is LMR-400 UltraFlex lower quality than standard LMR-400?
No — the electrical performance is essentially identical. The UltraFlex version trades some mechanical rigidity for flexibility. For fixed outdoor runs, standard LMR-400 is the right choice. For routing in tight spaces or racks, UltraFlex is better.
Can I use the same connectors for both versions?
Yes — LMR-400 UltraFlex is dimensionally compatible with standard LMR-400 connectors. The same crimping tools and connector bodies work for both.
Build Your LMR400 ULTRA FLEX Times or LMR400 Times Cable
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