RG-400 vs RG-142: Military-Grade Cables Compared
RG-400 and RG-142 are both military-specification double-shielded PTFE coaxial cables built for demanding environments. Both meet MIL-C-17 specifications and are used in aerospace, defense, and high-temperature industrial applications. The primary difference is conductor construction and cost.
The Short Answer
Both cables are appropriate for military and aerospace applications. RG-400 uses a stranded silver-plated copper center conductor which is slightly more flexible. RG-142 uses a silver-plated copper clad steel center conductor with better tensile strength for high-vibration environments.
Key Differences at a Glance
- Both rated to MIL-C-17 military specification
- Both use PTFE dielectric and FEP jacket with double silver-plated braid shield
- Both rated -55°C to +200°C temperature range
- RG-400 center conductor: 19×0.2mm stranded silver-plated copper
- RG-142 center conductor: silver-plated copper clad steel for higher tensile strength
Side-by-Side Specifications
| Specification | RG400 | RG142 |
|---|---|---|
| Impedance | 50 Ohm | 50 Ohm |
| Frequency Range | DC – 6 GHz | DC – 6 GHz |
| Velocity Factor | 0.7 | 0.7 |
| Dielectric | Solid PTFE | Solid PTFE |
| Shield | Double silver-plated copper braid | Double silver-plated copper braid |
| Jacket | FEP | FEP |
| Center Conductor | Silver-plated copper, 19×0.2mm | Silver-plated copper clad steel, 0.94mm |
| Min. Bend Radius | 0.75 in (19mm) | 1.0 in (25mm) |
| Max Voltage | 1400 VRMS | 1400 VRMS |
| Temperature Range | -55°C to +200°C | -55°C to +200°C |
| Weight | 2.6 lb/100ft | 2.8 lb/100ft |
Attenuation Comparison (dB per 100 ft)
| Frequency | RG400 | RG142 | Difference |
|---|---|---|---|
| 100 MHz | 3.5 dB | 3.8 dB | +0.3 dB (RG142 worse) |
| 450 MHz | 7.8 dB | 8.5 dB | +0.7 dB (RG142 worse) |
| 900 MHz | 11.5 dB | 12.5 dB | +1 dB (RG142 worse) |
| 1.8 GHz | 17 dB | 18.5 dB | +1.5 dB (RG142 worse) |
| 2.4 GHz | 20 dB | 21.5 dB | +1.5 dB (RG142 worse) |
| 5.8 GHz | 34 dB | 37 dB | +3 dB (RG142 worse) |
When to Choose Each Cable
Choose RG400 when:
- Applications requiring maximum flexibility
- Frequent flexing environments
- General mil-spec RF assemblies
Choose RG142 when:
- High-vibration aerospace applications
- Applications requiring mechanical strength
- NMO vehicle antenna mounts
Frequently Asked Questions
What is the difference between RG-400 and RG-142?
The main difference is the center conductor. RG-400 uses stranded silver-plated copper, making it slightly more flexible. RG-142 uses copper clad steel which is stronger under mechanical stress. Electrically they are nearly identical.
Can I use RG-142 or RG-400 for NMO vehicle antenna mounts?
Yes — both cables are used for NMO mobile vehicle antenna mounts, particularly in public safety, military vehicle, and high-temperature environments where standard PVC-jacketed cables would fail.
Build Your RG400 or RG142 Cable
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