50 Ohm vs 75 Ohm Coaxial Cables: What's the Difference?

Published by Wassalat Technical Team

One of the most common questions in the world of cabling is: "Should I use 50 Ohm or 75 Ohm coaxial cable?" The answer isn't always obvious, and using the wrong impedance can lead to signal reflections, poor performance, and equipment damage.

This comprehensive guide explains everything you need to know about 50Ω and 75Ω coaxial cables—including how they work, when to use each, and how to avoid costly mistakes.

What Is Impedance?

Impedance is the measure of opposition that a cable presents to alternating current (AC). In simple terms, it's the "resistance" the cable offers to the electrical signal traveling through it.

Coaxial cable impedance is determined by three physical factors:

1. Center conductor diameter – Thicker conductors have lower impedance
2. Dielectric material – The insulating material affects impedance
3. Outer shield diameter – Larger shields increase impedance

Impedance is measured in Ohms (Ω). The two most common standards are 50Ω and 75Ω.

Why 50Ω and 75Ω?

These two impedance values didn't happen by accident—they were chosen for specific engineering reasons.

50Ω – The Power Handling Standard

50Ω cables offer the best balance between power handling and signal loss. At 50Ω, a coaxial cable can carry the most power without arcing or overheating. This makes it ideal for transmitting RF power from transmitters to antennas.

• Optimal power handling – Maximum power transfer occurs at 50Ω
• Good attenuation – Signal loss is low at this impedance
• Versatile – Suitable for most RF applications

75Ω – The Low-Loss Standard

75Ω cables offer the lowest possible signal loss for a given cable size. At 75Ω, attenuation is minimized, making it ideal for long-distance video and data transmission.

• Minimum attenuation – Least signal loss per foot
• High bandwidth – Supports high-frequency signals
• Video optimized – Perfect for television and broadband

Key Differences Between 50Ω and 75Ω Coaxial Cables

Physical Differences

50Ω and 75Ω cables of the same series (RG-6 vs RG-58, for example) look similar but have different internal dimensions:

• Center conductor – 50Ω cables often have thicker center conductors
• Dielectric layer – 75Ω cables have a thicker dielectric for lower loss
• Impedance matching – The ratio of conductor diameters determines impedance

Performance Differences

50 Ohm Cables – Applications

50Ω cables are the standard for radio frequency (RF) and wireless communications. They're designed to efficiently transfer RF power from transmitters to antennas.

Common 50Ω Applications

• ? Two-Way Radios – Police, fire, emergency services, and amateur radio
• ? Wireless Networks – WISP, point-to-point, point-to-multipoint links
• ? Cellular Infrastructure – 4G LTE and 5G base stations
• ? WiFi Systems – Enterprise and outdoor WiFi installations
• ? Laboratory Equipment – RF testing, spectrum analyzers, signal generators
• ?️ Satellite Communications – Ground station equipment
• ? Amateur Radio – Ham radio transceivers and antennas
• ? Microwave Links – Point-to-point microwave backhaul

Popular 50Ω Cables

75 Ohm Cables – Applications

75Ω cables are the standard for video and data transmission. They're engineered for minimum signal loss over long distances.

Common 75Ω Applications

• ? Cable Television (CATV) – Residential and commercial TV distribution
• ? Satellite TV – Dish connections to set-top boxes
• ? CCTV Systems – Analog video surveillance
• ? Broadband Internet – Cable modem connections
• ? Professional Video – SDI, HD-SDI, 3G-SDI signals
• ? Broadcast Studios – Video routing and distribution
• ? Building Distribution – MATV and SMATV systems
• ? Digital Audio – AES/EBU digital audio connections

Popular 75Ω Cables

Side-by-Side Comparison

Here's a direct comparison of common 50Ω and 75Ω cables:

Can You Mix 50Ω and 75Ω?

The Problem with Mismatched Impedance

When a signal travels from a 50Ω cable into a 75Ω device (or vice versa), some of the signal is reflected back instead of being absorbed. This causes:

• Signal loss – Reflected signals reduce the power reaching the receiver
• Ghosting – Reflected signals can create duplicate images in video
• Standing waves – Reflected and forward signals interact, creating interference
• VSWR issues – Voltage Standing Wave Ratio increases, reducing efficiency
• Equipment damage – In high-power applications, reflected signals can damage transmitters

What Happens When You Mix?

Impedance Matching Solutions

If you must connect 50Ω and 75Ω components, use a matching transformer (balun) or impedance converter. These devices convert the impedance to match the system.

How to Choose the Right Cable

Step 1: Identify Your Equipment's Impedance

Check the specifications of all devices in your system:

• Transmitters and transceivers – Usually 50Ω for RF, 75Ω for video
• Antennas – Most are 50Ω (some satellite are 75Ω)
• Receivers – TV/Satellite receivers are 75Ω; radio receivers are 50Ω
• Testing equipment – Check labels on ports

Step 2: Determine Your Application

Step 3: Consider Cable Length

• Short runs (under 50 ft) – Most cable types will work. Choose based on equipment impedance.
• Medium runs (50–150 ft) – Use low-loss cables like RG-6 (75Ω) or LMR-240/400 (50Ω).
• Long runs (150+ ft) – Use RG-11 (75Ω), LMR-400/600 (50Ω), or consider fiber optic alternatives.

Connector Differences

50Ω and 75Ω connectors look similar but are not interchangeable. Using the wrong connector can damage both the cable and the equipment.

50Ω Connectors

• N-Type – Professional standard for outdoor RF (50Ω version)
• SMA – Small form factor for WiFi, cellular, IoT
• BNC (50Ω) – Lab test equipment, radios
• TNC – Threaded version of BNC, used in military and aerospace
• UHF (PL-259) – Older standard for amateur radio (uncontrolled impedance)

75Ω Connectors

• F-Type – Standard for CATV, satellite, and broadband (75Ω only)
• BNC (75Ω) – Video equipment, CCTV, broadcast
• RCA – Consumer video and audio

Common Problems & Solutions

Frequently Asked Questions (FAQ)

1. What happens if I use a 50Ω cable on a 75Ω system?

You'll experience about 4% signal loss (0.18 dB) and potential signal reflections. The system may work but with degraded performance. For professional installations, always use the correct impedance.

2. Can I use 75Ω cable for WiFi?

No. WiFi equipment expects 50Ω impedance. Using 75Ω cable will cause signal reflections and poor performance. Always use 50Ω cables like LMR-400 for WiFi installations.

3. Can I use 50Ω cable for TV?

No. TVs and set-top boxes expect 75Ω impedance. Using 50Ω cable will cause signal reflections and poor picture quality. Always use 75Ω cables like RG-6 for TV.

4. Why are satellite dishes 75Ω?

Satellite TV uses 75Ω because it's a video application with long cable runs. The low loss of 75Ω cable is ideal for bringing satellite signals from the dish to the receiver.

5. Can I use an F-Type connector on 50Ω cable?

No. F-Type connectors are specifically designed for 75Ω cable. Using them on 50Ω cable can cause signal loss and disconnection problems.

6. What is a balun?

A balun (balance-to-unbalance) is a device that converts between different impedances. It can match 50Ω to 75Ω, but adds some signal loss.

7. Which cable has less signal loss, 50Ω or 75Ω?

75Ω cables generally have lower attenuation than equivalent 50Ω cables. This is why 75Ω is preferred for long video runs.

8. Can I tell by looking if a cable is 50Ω or 75Ω?

Sometimes. 50Ω cables often have thicker center conductors. However, the only sure way is to check the cable's markings or specifications.

9. Is RG-6 50Ω or 75Ω?

RG-6 is 75Ω. It's the most common cable for TV, satellite, and broadband internet.

10. Is LMR-400 50Ω or 75Ω?

LMR-400 is 50Ω. It's one of the most popular cables for wireless networks and RF applications.

11. What's the difference between 50Ω and 75Ω BNC connectors?

75Ω BNC connectors have a smaller center pin than 50Ω connectors. Using a 50Ω BNC on a 75Ω system can cause signal loss and potential damage.

12. Can I use 50Ω and 75Ω cables together with adapters?

It's not recommended. Even with impedance-matching adapters, you'll still lose signal strength. Use the same impedance throughout your entire system.

? Related Articles

• Complete Guide to Coaxial Cables
• RG6 vs RG11 – Which One Do You Need?
• Coaxial Cable Connectors Guide
• Cable Attenuation Explained
• The Complete Guide to Antennas
• Browse Coaxial Cables →

Last Updated: July 2026

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