Use a 75-ohm coaxial cable with F-type connectors when carrying television, satellite, cable-modem, or other broadband RF signals. The 75-ohm value is the cable’s characteristic impedance, not the resistance you will read with a multimeter. The cable, connector, and termination method must be compatible as one assembly.

After fitting the connectors, use a coax tester to check for opens, shorts, and endpoint identity. A basic tester confirms wiring continuity; it does not prove that the finished run has acceptable RF loss.

Where Is 75-Ohm Coaxial Cable With F-Type Connectors Used?

Seventy-five-ohm coax is common in residential and commercial distribution systems, including:

• Over-the-air television antennas and satellite receivers
• Cable television and cable-modem connections
• Video distribution and some CCTV installations
• RF links between splitters, amplifiers, wall plates, and set-top equipment

Its impedance is designed for the source, cable, and load to work together with minimal signal reflection. A 50-ohm cable may look similar and may pass a simple continuity test, but it is not the correct substitute for a 75-ohm television distribution path.

How Do You Match Coaxial Cables and F-Type Connectors?

Choose the connector from the cable’s actual construction, not from impedance alone. Common RG designations provide a useful starting point:

• RG-6: The usual choice for modern satellite, antenna, and cable installations. It is thicker than RG-59 and generally has lower loss at higher frequencies.
• RG-59: A smaller cable often found in older video or short indoor runs. RG-59 connectors are not interchangeable with RG-6 connectors.
• RG-11: A larger, lower-loss option for longer runs, requiring connectors made for its larger diameter.

RG numbers are not complete specifications. Check the manufacturer’s outside diameter, dielectric size, center-conductor diameter, jacket type, and frequency rating. Cable size affects how far the center conductor projects through the F connector and how the connector’s internal sleeve grips the jacket.

Also inspect the shield. Basic coax may use braid, while other cable uses foil plus braid or quad shielding. Select an F connector specifically rated for the cable’s shield and jacket construction. Compression connectors usually provide the most consistent mechanical and weather-resistant termination; crimp and twist-on types must still match the cable dimensions and intended use.

How Do You Prepare and Terminate the Cable?

1. Cut the cable square. A diagonal cut can prevent the connector from seating evenly.
2. Use the connector’s strip guide. Remove the specified length of jacket without nicking the braid, foil, or dielectric. Do not rely on one strip dimension for every F connector.
3. Prepare the shield. Fold the braid back over the jacket as directed. Keep foil in the position specified by the connector instructions; do not allow loose strands to extend into the center-contact area.
4. Expose the center conductor. The dielectric should be clean and undamaged. Trim the center conductor to the connector’s required projection, commonly only a small amount beyond the nut.
5. Insert the connector fully. Push the connector straight onto the cable until the dielectric reaches its internal stop and the shield remains under the connector’s contact area.
6. Secure the connector. Compress or crimp it with the matching tool. Tighten a threaded connector firmly, but do not use it as a substitute for the specified compression or crimp method.

Before connecting equipment, inspect both ends. The center conductor must be continuous and centered, with no braid or foil touching it. Check that no stray braid protrudes past the connector face, then perform a gentle pull test. A connector that slides off, spins excessively, or exposes damaged dielectric should be remade.

How Do You Use a Coax Tester—and What Can It Not Measure?

Disconnect the cable from powered equipment before testing. For a two-piece tester, attach the main unit to one end and the labeled remote to the other. If the tester uses interchangeable remotes, record each remote number so you can identify cables at a distribution panel or wall outlet.

1. Connect the tester or its F adapter securely.
2. Run the continuity test and read the result.
3. Interpret an open as a broken center conductor, missing contact, disconnected remote, or poorly seated connector.
4. Interpret a short as center conductor contact with braid, foil, a connector shell, or another conductive fault.
5. Wiggle each connector and cable section while testing to reveal intermittent faults.
6. Use the remote-ID or mapping function, if provided, to match an unknown outlet to the correct cable end.

Continuity and mapping tests do not measure characteristic impedance, insertion loss, return loss, shielding effectiveness, signal level, or frequency response. A cable can pass for opens and shorts while using the wrong impedance, having excessive length or damage, admitting water, or containing a high-loss connector. Use an RF signal meter, spectrum analyzer, cable certifier, or suitable network analyzer when television or cable-modem performance must be verified.