RG-316 vs RG-174: Which Thin Coax Is Right for Your Application?
RG-316 and RG-174 are both thin, flexible 50-ohm cables used for short connections, pigtails, and internal device wiring. RG-174 uses a PVC jacket and PE dielectric, making it affordable and widely available. RG-316 uses PTFE (Teflon) throughout — a higher-grade material that extends temperature range, improves loss, and makes it suitable for precision lab and test work.
The Short Answer
RG-174 is fine for consumer electronics pigtails, GPS cables, and general short connections up to 1 GHz. Choose RG-316 for test equipment, SMA bench cables, any application above 1 GHz, or environments with high temperature or chemical exposure.
Key Differences at a Glance
- RG-316 uses PTFE dielectric and jacket; RG-174 uses PE dielectric and PVC jacket
- RG-316 is rated to 200°C; RG-174 is limited to 85°C
- RG-316 loss at 1 GHz: ~16 dB/100ft vs RG-174's ~21 dB/100ft
- Both cables are approximately the same diameter (~0.098") and equally flexible
- RG-316 costs roughly 2-3× more than RG-174 per foot
Side-by-Side Specifications
| Specification | RG316 | RG174 |
|---|---|---|
| Impedance | 50 Ohm | 50 Ohm |
| Frequency Range | DC – 6 GHz | DC – 3 GHz |
| Velocity Factor | 0.7 | 0.66 |
| Dielectric | Solid PTFE | Solid PE |
| Shield | Silver-plated copper braid (90%) | Tinned copper braid (90%) |
| Jacket | FEP | PVC |
| Center Conductor | Silver-plated copper clad steel, 7×0.17mm | Bare copper clad steel, 7×0.16mm |
| Min. Bend Radius | 0.5 in (13mm) | 0.5 in (13mm) |
| Max Voltage | 1200 VRMS | 1100 VRMS |
| Temperature Range | -55°C to +200°C | -40°C to +85°C |
| Weight | 1.0 lb/100ft | 0.8 lb/100ft |
Attenuation Comparison (dB per 100 ft)
| Frequency | RG316 | RG174 | Difference |
|---|---|---|---|
| 100 MHz | 5.5 dB | 6.6 dB | +1.1 dB (RG174 worse) |
| 450 MHz | 12.5 dB | 14.5 dB | +2 dB (RG174 worse) |
| 900 MHz | 18.5 dB | 21.5 dB | +3 dB (RG174 worse) |
| 1.8 GHz | 27 dB | 32 dB | +5 dB (RG174 worse) |
| 2.4 GHz | 32 dB | 38 dB | +6 dB (RG174 worse) |
| 5.8 GHz | 55 dB | 65 dB | +10 dB (RG174 worse) |
When to Choose Each Cable
Choose RG316 when:
- Lab test leads and bench cables
- SMA patch cables for test equipment
- High temperature environments
- Applications above 1 GHz
Choose RG174 when:
- GPS antenna pigtails
- Consumer electronics wiring
- Short router antenna connections
- Cost-sensitive short runs
Frequently Asked Questions
Can I use RG-174 instead of RG-316?
For short runs under 3 feet at frequencies below 1 GHz, RG-174 is an acceptable substitute. For test equipment, lab setups, or any application above 1 GHz, RG-316's lower loss and PTFE construction make a meaningful difference.
What connectors work with both cables?
Both RG-316 and RG-174 have similar outer diameters and use the same connector form factors — SMA, BNC, MCX, MMCX, and other miniature RF connectors. Check that connectors are specifically sized for the cable diameter.
Is RG-316 better than RG-174 for GPS cables?
For a typical GPS antenna pigtail under 6 feet, the difference is negligible. RG-316 is overkill for basic GPS use. It becomes worthwhile in GPS timing applications requiring precision phase stability or in high-temperature vehicle environments.
Build Your RG316 or RG174 Cable
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