Use RG174 when you need a low-cost, flexible 50-ohm coax pigtail for a short, low-power indoor run. Use RG316 when the cable must survive more heat, outdoor exposure, tighter RF acceptance checks, or a more demanding test/lab environment. Both cable families are small, flexible RF cables, but they are not interchangeable once frequency, length, connector quality, and temperature become important.
For most compact RF designs, the safer question is not “which cable is better?” It is: “How much loss can this cable add, how hot will the assembly get, how sharply must it bend, and which connector pair does the device actually need?”
Quick Comparison
| Selection factor | RG174 (GLRG174) | RG316 (GLRG316) |
|---|---|---|
| Impedance | 50 ±2 ohm | 50 ±2 ohm |
| Jacket outer diameter | 2.8 mm | 2.54 mm |
| Dielectric / jacket | Solid PE / PVC | PTFE / FEP |
| Velocity of propagation | 66% | 69.5% |
| Capacitance | 96 pF/m | 95 pF/m |
| Peak power | 3.5 kW | 2.4 kW |
| VSWR (specified band) | < 1.30, DC to 3 GHz | < 1.25, DC to 3 GHz |
| Operating temperature | -20 to +70 C | -55 to +200 C |
| Best fit | Short, flexible, low-cost pigtails | Heat, outdoor, lab, and more stable RF assemblies |
| Main trade-off | Loss rises with length and frequency; lower temperature range | Higher cost and tighter to terminate; usually overkill for simple indoor pigtails |
The figures above are GlobalRF’s own GLRG174 and GLRG316 cable specifications. Both are 50-ohm miniature cables; the practical difference is the dielectric and jacket system (PE/PVC vs PTFE/FEP), which drives the temperature range, peak power, and how stable the cable stays in harsh conditions. For a specific build, always confirm against the exact part datasheet.
Signal Loss and Frequency: Keep RG174 Short
RG174 is attractive because it is small and flexible. GlobalRF’s GLRG174 is a 50-ohm miniature cable with a solid PE dielectric, black PVC jacket, 66% velocity of propagation, a 2.8 mm jacket diameter, and VSWR held under 1.30 from DC to 3 GHz. That construction suits short RF pigtails, compact GPS antenna leads, short antenna feed connections, and internal device wiring.
It is not the right choice for long high-frequency runs. As frequency and length increase, cable loss becomes a real design constraint, and a thin PE cable loses more per meter than a larger low-loss line. If your assembly is longer than a short board-to-panel jumper, calculate the loss before you buy.
RG316 usually gives you more environmental and mechanical headroom. GlobalRF’s GLRG316 is a 50-ohm cable with a PTFE dielectric, FEP jacket, 69.5% velocity of propagation, VSWR under 1.25 from DC to 3 GHz, and a -55 C to +200 C operating range, versus -20 to +70 C for GLRG174. That extra thermal margin, together with the silver-plated conductor and PTFE dielectric, is often why engineers move from RG174 to RG316 even when both cables are physically small.
Bend Radius, Jacket, and Temperature Matter
Cable choice is not only about dB loss. A cable can look fine in a table and still fail in a real enclosure if it is bent too tightly, routed next to heat, or pulled against a connector.
RG174 is easy to route because it is small and flexible, with a thin 2.8 mm PVC jacket. For short indoor cables, that tight bend capability is a real advantage and helps explain why RG174 is common in compact RF layouts. Confirm the exact minimum bend radius on the part datasheet before committing to a tight routing path.
RG316 is usually chosen when the cable must keep its electrical behavior more stable under temperature or handling stress. Its PTFE/FEP construction is more suitable for hot environments, outdoor devices, or test assemblies that need consistent performance. If the cable sits near an engine, an outdoor enclosure, a transmitter, or a hot PCB area, RG316 is often the safer first sample.
Connector Choice Can Matter As Much As Cable Type
Many RG174 and RG316 assemblies fail because the cable family was chosen correctly but the termination was not. A short RG174 SMA cable can work well in one device and perform poorly in another if the crimp is weak, the bend relief is poor, or the wrong connector gender is ordered.
Before ordering, confirm:
| RFQ detail | Why it matters |
|---|---|
| Connector A and B | SMA, RP-SMA, BNC, MMCX, FAKRA, TS9, U.FL, or another interface changes both assembly method and use case. |
| Cable length | Loss is length-dependent; the same cable can be acceptable at 10 cm and poor at 1 m. |
| Frequency band | A GPS pigtail and a 2.4 GHz antenna extension do not have the same loss tolerance. |
| Target loss budget | Tell the supplier the maximum acceptable insertion loss if the system is sensitive. |
| Bend radius and routing | Tight bends can deform the dielectric and affect impedance. |
| Temperature and environment | Indoor, outdoor, automotive, enclosure heat, and UV exposure change the right jacket choice. |
| Quantity and test needs | Prototype samples may need VNA checks, continuity tests, or custom labeling. |
When RG174 Is the Better Choice
Choose RG174 when the cable is short, the RF power is low, and the environment is controlled. Typical examples include internal antenna pigtails, short GPS receiver leads, compact IoT devices, small RF modules, and cost-sensitive cable assemblies where the run length is tightly controlled.
RG174 is also useful when flexibility and routing space matter more than maximum temperature rating. If a device only needs a short 50-ohm connection inside a plastic enclosure, RG174 may be the practical choice.
Avoid stretching RG174 beyond its comfort zone. If the run gets longer, the device operates at higher frequency, or the cable is exposed to heat, ask for loss calculations and consider RG316, RG58, or another lower-loss cable family.
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When RG316 Is the Safer Choice
Choose RG316 when the assembly must survive higher temperature, outdoor conditions, more demanding RF checks, or repeated lab/test use. Its PTFE/FEP construction and broader temperature capability make it more forgiving in harsh conditions.
RG316 is often a better candidate for outdoor wireless equipment, SDR/test benches, automotive electronics, drone/video systems, and antenna assemblies that see heat or movement. It can cost more than RG174, but the extra stability can be cheaper than debugging RF loss, VSWR, or intermittent connector problems later.
Practical Selection Rule
Use this rule before asking for samples:
- If the cable is a short indoor pigtail and cost matters, start with RG174.
- If the cable sees heat, outdoor exposure, lab use, or higher-frequency stability requirements, start with RG316.
- If the cable must run longer or carry more RF power, do not force either cable. Move to a lower-loss family such as RG58 or another cable specified for the frequency and power level.
- If the assembly is for production, request the actual cable datasheet, connector drawing, and sample test report before approving the build.
What To Send a Supplier
For a custom RG174 or RG316 cable assembly, send the supplier this information:
| Information | Example |
|---|---|
| Cable family | RG174 or RG316 |
| Frequency band | GPS L1, 433 MHz, 915 MHz, 2.4 GHz, etc. |
| Length | 100 mm, 300 mm, 1 m, or custom |
| Connector A / B | SMA male to MMCX, FAKRA to SMA, BNC to SMA |
| Impedance | 50 ohm |
| Environment | Indoor, outdoor, automotive, high temperature |
| Target loss | Maximum insertion loss if known |
| Quantity | Prototype and production quantity |
| Testing | Continuity, VSWR, insertion loss, labeling, packaging |
The more clearly you define the RF conditions, the less likely the supplier is to quote a cable that fits mechanically but fails electrically.
FAQ
Is RG174 the same as RG316?
No. Both are small 50-ohm coax cable families, but RG174 commonly uses PE/PVC construction, while RG316 commonly uses PTFE/FEP construction. RG316 is usually selected for higher temperature and more demanding RF environments.
Is RG174 good for GPS antenna cables?
Yes, RG174 can work for short GPS antenna pigtails or compact antenna feeds. Keep the cable short, avoid sharp bends, and verify the final insertion loss if the receiver has a tight link budget.
Can RG174 use SMA connectors?
Yes. RG174 is commonly terminated with SMA and other small RF connectors. The correct crimp ferrule, stripping dimensions, strain relief, and connector gender matter as much as the cable type.
Does RG316 always have lower loss than RG174?
Not always. Loss depends on the exact cable construction, frequency, and length. RG316 is often chosen for thermal and mechanical stability, not only for raw attenuation. Always compare the actual datasheets for the parts you will buy.
How long can an RG174 cable be?
There is no universal safe length. It depends on frequency, power, target loss, connector losses, and receiver sensitivity. For higher-frequency or loss-sensitive systems, keep RG174 short and calculate the total path loss before ordering.
Conclusion
RG174 is a good fit for short, flexible, low-power RF pigtails. RG316 is the safer option when heat, outdoor exposure, higher-frequency stability, or stricter testing matters. If neither cable meets the loss budget, move to a thicker or lower-loss coax family instead of forcing a miniature cable into the job.
For a custom RF cable assembly quote, send your frequency band, cable length, connector pair, impedance, target loss, operating environment, and expected quantity. That information lets an engineering team recommend whether RG174, RG316, or another coax family is the right starting point. Browse our RG174 coaxial cable and RG316 coaxial cable, or the full RF cable range.
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