RG58 Cable: Specs, Loss & Outdoor Routing

Oct 16,2025

Preface

When setting up a reliable RF communication line — whether in a smart home, a hotel network, or an outdoor IoT gateway — the cable often becomes the unsung hero. A 50 ohm coax cable like RG58 bridges your antennas, routers, and modules, carrying signals from DC to 6 GHz with minimal compromise. But “minimal” depends on how far you run it, how you terminate it, and what environment you expose it to.

At TEJTE, we’ve seen RG58 cables thrive in everything from office networks and gaming rooms to outdoor Wi-Fi repeaters and vehicle installations. Yet many engineers and buyers still ask: Where does RG58 stop making sense, and when should you move to RG316 or LMR-240? Let’s break that down with hard data — not marketing slogans.

Should you pick RG58 or RG316 for this run?

At first glance, both RG58 and RG316 are 50-ohm coaxial cables rated up to 6 GHz, commonly used with SMA to SMA cable assemblies or SMA extension cables. But the trade-offs appear once you factor in attenuation, bend radius, and environmental flexibility.

Parameter	RG58	RG316
Structure	Bare copper inner, PE insulation, Al tape + CCA braid, PVC jacket	Silver-plated copper (7×0.175 mm), PTFE insulation, silver braid, FEP jacket
Attenuation (dB/100 m)	7.66 @ 100 MHz, 21.2 @ 400 MHz, 43.2 @ 900 MHz, 105.2 @ 3 GHz	0.29 @ 100 MHz, 0.88 @ 900 MHz, 1.46 @ 2.4 GHz, 2.34 @ 6 GHz
Power (CW, 25 °C)	Peak 1.8 kW	78 W @ 2.4 GHz
Min. Bend Radius	50 mm	15 mm
Temperature Range	-20 ~ +70 °C	-55 ~ +150 °C
Screening Effectiveness	≥ 90 dB	High (Silver braid)
Outer Diameter	5.0 mm	2.5 mm

If you’re routing cables inside racks or vehicle panels, RG316 wins on flexibility and thermal stability. Its PTFE dielectric and FEP jacket allow tighter bends and stable impedance in hot environments like engine bays or base-station enclosures.

But if your build emphasizes lower loss and higher power handling, RG58 still offers superior performance for fixed indoor or semi-outdoor setups. At 2.4 GHz, RG58 loses about 0.21 dB/m, compared to RG316’s 0.29 dB/m — a measurable gap when you’re running multiple meters.

At 5–6 GHz, the trade shifts: RG316’s smaller dielectric keeps loss predictable, while RG58’s PVC jacket may drift slightly under temperature rise. As a rule of thumb:

For short patch leads (< 2 m) inside devices or test setups → RG316 is ideal.

- For antenna feeders (> 3 m) or SMA to SMA extensions in access points → RG58 gives you cleaner margins.
You can explore both versions directly under TEJTE’s RF Coaxial Cable Guide — where RG58 and RG316 are benchmarked side by side with frequency-loss curves.

How does RG58 stack up against LMR-200 / LMR-240 for long outdoor routes?

Once your coax run exceeds 5–10 meters, loss compounds quickly — and this is where LMR-series cables enter the conversation. Both LMR-200 and LMR-240 maintain the same 50 Ω impedance as RG58 but offer foam PE dielectric and dual-shield construction (aluminum foil + tinned copper braid), significantly improving attenuation and EMI rejection.

Parameter	RG58	LMR-200	LMR-240
Dielectric	Solid PE	Foam PE	Foam PE
Outer Diameter	5.0 mm	5.0 mm	6.1 mm
Attenuation (dB/100 m @ 2.4 GHz)	21	15	12
Attenuation (dB/100 m @ 5 GHz)	~ 33	23	19
Power Rating (@ 2.4 GHz)	160 W	200 W	240 W
Min. Bend Radius	50 mm	25 mm (static)	30 mm
Jacket	PVC	PVC (black)	PVC (black)
Temperature Range	-20 ~ +70 °C	-20 ~ +80 °C	-20 ~ +80 °C

When you route feeders on rooftops or poles, every decibel counts. For a 10 m line at 5 GHz:

RG58 ≈ 3.3 dB total loss
LMR-200 ≈ 2.3 dB
LMR-240 ≈ 1.9 dB

That 1.4 dB difference may sound small, but it translates to nearly 30% higher power reaching your antenna — a decisive factor in point-to-point links or long Wi-Fi bridge runs.

Budget and handling also come into play. LMR-240 is heavier and stiffer (6.1 mm diameter), so for portable or curved runs around walls, RG58 still wins on manageability. But for permanent outdoor feeders, LMR-240’s dual shield and UV-resistant jacket are worth the small cost bump.

From an installation standpoint, TEJTE supplies compatible N-type to SMA adapter cables and weather-sealed RG58 assemblies (see RG58 N-to-SMA 5 m cable) that help bridge mixed-connector systems without stacking multiple barrel adapters — keeping VSWR below 1.25.

Practical tip: If your route exceeds 15 m at 5 GHz, jump from RG58 to LMR-240. Below that, RG58 is economical, flexible, and performs adequately for APs, routers, and IoT relays in semi-outdoor setups.

How long can an RG58 cable be before link-budget loss gets risky?

Cable length is the silent signal killer in RF systems. Whether you’re connecting a router to an external antenna or chaining SMA extension cables, every meter of RG58 coax introduces loss that adds up faster than many expect.

Using your real TEJTE attenuation data (20 °C, sea level):

Frequency (GHz)	Loss (dB/m)	3 m	5 m	10 m
2.4	0.21	0.63	1.05	2.10
5.0	0.33	0.99	1.65	3.30
6.0	0.40	1.20	2.00	4.00

Add roughly 0.1–0.3 dB per connector or adapter (SMA/N) depending on quality.

For example, a 5 m RG58 SMA-SMA line with two terminations can lose ≈ 2 dB @ 5 GHz, which is already 37% signal reduction.

To plan conservatively, engineers often set a total path-loss budget:

Loss_total = Cable Loss + Connector Loss ≤ RSSI Target − SNR Margin

Say your access point needs −65 dBm RSSI for stable throughput and your noise floor sits at −90 dBm. You can afford ~25 dB total path loss, including antenna gain and cable attenuation. With RG58, that limit typically equates to ≤ 8 m at 5 GHz or ≤ 12 m @ 2.4 GHz before you risk performance drops.

If your design pushes beyond that — like outdoor repeaters or vehicle antennas — move to LMR-200 or LMR-240, which cut insertion loss nearly in half.

You can find more practical loss estimations and comparison charts in TEJTE’s RF Cable Guide, which details real-world data on SMA, BNC, and N-type assemblies.

Will your RG58 survive the environment — what temperature rating and jacket do you need?

Outdoor installations expose RG58 cables to far harsher conditions than lab setups ever see. The standard PVC jacket on TEJTE’s 50 ohm coax cable is durable enough for most indoor and semi-sheltered environments — think smart home routers, café Wi-Fi, or hotel repeater systems — but long exposure to UV or wide temperature swings can alter performance.
According to TEJTE’s verified specs, RG58 operates reliably between −20 °C and +70 °C. This range comfortably covers most temperate climates, but in rooftops or desert sites, it’s wise to add UV-resistant boots or cable sleeves (UV/IP boots for SMA/N connectors) to prevent jacket degradation. The screening attenuation ≥ 90 dB also means the cable resists EMI from nearby power lines or Wi-Fi clusters — a quiet but vital contributor to signal stability.
In contrast, RG316 and LMR-series cables employ FEP or PE jackets with broader thermal margins (−55 °C to +150 °C for RG316). If you expect direct sun or sub-zero frost, consider RG58 cables with black PVC or FEP jacketing as an upgrade path.
Temperature rating ranges, UV/abrasion resistance, and drip-loop practice
Small routing habits make big differences outdoors:
- Always form a downward “drip loop” before connectors to keep moisture from seeping into SMA or N-type joints.
- Use rubber grommets or strain boots at wall entries — TEJTE supplies purpose-built grommets for SMA/N assemblies that maintain seal compression even after hundreds of flexes.
- Avoid prolonged contact with metal conduits in hot climates; radiant heat can lift the outer jacket temperature above its +70 °C rating.
For installations that blend indoor and outdoor sections, many engineers combine RG58 feeders with short RG316 jumpers to handle high-heat zones — a flexible, low-cost hybrid that keeps both reliability and manageability in check.
You’ll find more environmental layout visuals and case studies inside TEJTE’s SMA Extension Cable Outdoor Setup Guide.

Do you need N-type to SMA or straight SMA ends for your chain?

Choosing the correct connector configuration is as critical as the cable itself. The RG58 cable family supports multiple termination types — from SMA male-to-male jumpers to N-type to SMA adapter cables — and the wrong pairing can easily raise VSWR or introduce micro-losses.

Connector Type	Impedance	Frequency Range	VSWR	Temperature Range	Durability
SMA-JJ (SMA male to SMA male)	50 Ω	DC – 6 GHz	≤ 1.25	-45 °C ~ +125 °C	≥ 500 cycles
N/SMA-KKF (N female to SMA female, 4-hole flange)	50 Ω	DC – 6 GHz	≤ 1.20	-45 °C ~ +125 °C	≥ 500 cycles

As seen in TEJTE’s part no. 08764 (N/SMA-KKF), the gold-plated brass interface and PET dielectric provide both mechanical stability and low contact resistance — ideal for weather-sealed cabinets. For short jumper runs, SMA to SMA cables like TEJTE’s SMA-JJ 3 m RG58 assembly maintain excellent < 1.25 VSWR up to 6 GHz, ensuring minimal reflection.

Pick N-type to SMA adapter cable vs barrel adapters to minimize VSWR

When chaining multiple segments — say, an N-type antenna to an SMA-based modem — always favor a factory-terminated N-to-SMA coax cable over stacking adapters. Each extra joint adds ~0.1 – 0.3 dB of loss and slight phase ripple. Using a pre-terminated RG58 N-to-SMA 5 m cable from TEJTE’s RF Cable line avoids that cumulative degradation and reduces connector strain under vibration.

Male-to-male vs male-to-female ends by device/antenna patterns

Male-to-male (SMA-JJ): Common for signal analyzer or rack interconnects where both ports are female.
Male-to-female (SMA-JF): Typical in antenna feeder lines, routers, and repeaters.
N-male to SMA-female: The outdoor classic — fits heavy-duty base antennas while feeding lighter SMA gear indoors.

For anyone building modular chains, refer to TEJTE’s SMA to N Adapter Selection Guide — it details torque values, sealing tips, and IP67 mounting practices tailored to RG-series cables.

How do you install and test RG58 without hurting connectors or return loss?

Choose pigtails (U.FL to SMA) for internal RF modules, typically 10–30 cm.
Use jumpers (SMA-M to SMA-M) between instruments; they handle repeated cycles (> 500).
For enclosures, the panel feed-through SMA bulkhead provides sealing with nuts + washers and can be upgraded to IP67 boots – see TEJTE’s SMA bulkhead guide.

How do you terminate and strain-relieve RG316 to SMA cleanly?

Even the best-spec 50 ohm coax cable can underperform if mishandled. A slight over-torque or a sharp bend near the SMA connector can elevate VSWR or create micro-fractures in the dielectric. Installation discipline keeps your line within its rated loss envelope.

Torque, ESD, bend-radius discipline and connector care

For SMA connectors, always apply torque between 0.56 – 0.79 N·m (5 – 7 in-lb) — enough to seat the threads without deforming the pin. TEJTE’s engineers recommend using a dedicated SMA torque wrench (SMA/N torque tools) instead of finger-tightening, especially in vibration-prone setups.

Keep the minimum bend radius at or above 50 mm for RG58 (25 mm for RG316). One common rule: if the cable bends tighter than a bottle cap, it’s too much.

During assembly:

Avoid routing near power transformers or motor drivers to preserve the 90 dB shielding margin.
Ground both ends during handling to prevent ESD discharge through the center conductor.
Use strain-relief boots and zip-ties with rubber sleeves to distribute tension evenly.

Quick acceptance: continuity + spot RF cable loss / SMA cable loss check

Post-installation testing shouldn’t require a full lab bench. A simple continuity check (multimeter or TDR) verifies no open or short circuits, while a handheld RF power meter or VSWR tester confirms the run’s integrity.

Typical benchmarks:

Insertion loss ≤ 2 dB @ 5 m, 5 GHz (including connectors)
VSWR ≤ 1.25 for SMA-terminated lines
No connector heating after 10 minutes of TX at 5 GHz under 10 W

Order in one pass: which RG58 cable SKU matches your use case?

When you’re balancing frequency, run length, and connector type, the smartest move is to pick a pre-terminated assembly that already fits your RF chain. TEJTE offers RG58 assemblies with SMA-SMA, SMA-N, and mixed ends, each tuned for 50 Ω impedance and DC – 6 GHz bandwidth.

Ends	Frequency (GHz)	Length (m)	Estimated Loss (dB)	Min Bend Radius	Outdoor Rating	Suggested TEJTE P/N
SMA-M to SMA-M	2.4 / 5 / 6	1 / 2 / 3	0.25 / 0.50 / 0.75 @ 2.4 GHz 0.35 / 0.70 / 1.05 @ 5 GHz	50 mm	Indoor PVC	RG58-SMA-M/M-3M
SMA-M to SMA-F	2.4 / 5 / 6	5 / 10	1.05 / 2.10 @ 2.4 GHz 1.65 / 3.30 @ 5 GHz	50 mm	PVC or FEP	RG58-SMA-M/F-5M
N-M to SMA-F	2.4 / 5 / 6	5 / 10 / 30	1.05 / 2.10 / 6.30 @ 2.4 GHz 1.65 / 3.30 / 9.90 @ 5 GHz	60 mm	UV black PVC	RG58-N/M-SMA/F-10M

These values derive from TEJTE’s measured attenuation (0.21 dB/m @ 2.4 GHz, 0.33 dB/m @ 5 GHz, 0.4 dB/m @ 6 GHz) plus a 0.2 dB allowance per connector.

For indoor use — routers, gaming rooms, or office racks — the 3 m SMA-SMA variant keeps loss under 1 dB while staying flexible. For longer outdoor feeders, the N-to-SMA RG58 10 m cable combines weather resistance with consistent impedance.

In many IoT or smart-home installations, engineers mix RG58 feeders with short RG316 jumpers to handle temperature transitions. You can find detailed cross-application examples in TEJTE’s RF Cable Guide and SMA Extension Cable Setup.

Can RG58 handle your power — how do you verify rating and derating?

Power handling defines the line’s ceiling. At 25 °C, RG58 50 ohm coax cable safely carries around 160 W @ 2.4 GHz and 100 W @ 5 GHz, with a rated VSWR ≤ 1.20.

However, power capacity declines with temperature rise and duty cycle. TEJTE recommends using the following field formula:

Power & Derating Calculator

[P_{allow} = P_{25°C} × [1 – 0.005 × (T_{amb} – 25)] × Duty_{factor}]

Input	Typical Values	Result / Advisory
P_in	100 W
Duty Cycle	80%
Ambient Temp	60 °C
P_allow	≈ 80 W	→ Safe margin
If P_in > P_allow	—	Shorten run or upgrade to LMR-240

That 0.5 % per °C derating curve matches real-world field observations: in summer rooftops at +70 °C, effective power capacity drops nearly 25 %.

Field cues: connector warmth, intermittent VSWR spikes, and when to stop

During continuous transmission, gently touch the SMA nut — if it becomes noticeably warm, the inner dielectric may be heating. Rising return-loss ripples or sudden VSWR spikes on a handheld analyzer often indicate over-stress. Reduce power, verify torque, or switch to a thicker LMR-series cable.

For high-power, long-duty RF tasks — like FM transmitters or repeater feeds — RG58 performs best below 100 W. Above that, the foam-PE LMR family offers safer margins.

You can explore TEJTE’s technical comparison of RG58 vs RG316 vs LMR240 inside our coaxial cable blog cluster, which consolidates attenuation tables, jacket ratings, and VSWR test data.

FAQs

Q1. How much power can RG58 carry compared with RG316 at Wi-Fi bands?

At 2.4 GHz, RG58 handles ≈ 160 W continuous, while RG316 caps near 78 W. The thicker copper core dissipates heat better, so RG58 is preferable for routers or access points running 24/7.

Q2. Which cable has a higher power rating — RG58 or RG316 — and when should I move to LMR-240?

Use RG58 up to 8 m and < 120 W. Beyond that, attenuation compounds; LMR-240 halves the loss and supports > 200 W continuous.

Q3. How long can RG58 run before loss forces relocation of the radio or a switch to LMR?

At 5 GHz, a 10 m RG58 run loses ≈ 3.3 dB (33 %), while LMR-240 loses ≈ 1.9 dB. If your link budget exceeds 25 dB loss headroom, switch cables.

Q4. What jacket and temperature rating should I choose for rooftop or vehicle installs?

Select black PVC RG58 (−20 ~ +70 °C) for standard outdoor use, or FEP RG58 (−45 ~ +125 °C) for heat-exposed zones. Pair with UV-boots and grommets from TEJTE’s connector series.

Q5. When is an N-to-SMA adapter cable better than stacking barrel adapters?

Every extra adapter adds 0.2–0.3 dB loss and can raise VSWR. Choose a single N-to-SMA RG58 assembly to keep return loss low and maintain mechanical stability.

Q6. How do I verify RF cable loss and return loss on a new RG58 run without lab gear?

Check continuity and use a handheld SWR meter or spectrum analyzer. Typical readings: ≤ 1.25 VSWR and ≤ 2 dB loss for a 5 m SMA extension cable.

Q7. What bend-radius and strain-relief rules keep RG58 alive in vibration or wind?

Maintain ≥ 50 mm radius and use soft tie-downs every 30 cm. Avoid tight U-loops behind antennas; they cause micro-cracks in the PE dielectric.

Closing Note

The RG58 cable remains one of the most balanced and widely used 50 ohm coax cables in RF engineering — bridging affordability, power capacity, and ease of termination. From home IoT to commercial networks, its performance scales when paired with proper connectors, correct length planning, and sound installation habits.

For a deeper technical dive, schematics, and accessory matching, visit TEJTE’s RF Cables and Connectors hub and the TEJTE Blog on Coax and SMA Assemblies.

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