K4 Stud with SO-239

K4A Antenna Stud Mount (SO-239)

The K4A is a standard antenna stud used to connect your antenna to coax with a PL-259 connector.

This is a simple part, but it’s an important one. A good stud gives you a solid, reliable connection. A cheap one can cause problems—loose connections, corrosion, or inconsistent performance over time.

What to Expect

• Direct connection for PL-259 coax (SO-239 socket)
• Standard 3/8"-24 threads for most CB antennas
• Solid, stable mounting when installed correctly
• Designed to hold up under vibration and outdoor use

Where It Fits

This stud is commonly used for:

• Mirror mounts on semi trucks
• Roof or bracket-mounted antennas
• Any setup using standard CB coax with a PL-259 connector

Build and Construction

• Chrome-plated machined brass body
• Stainless steel hardware
• Nylon insulators for proper isolation
• Fits standard 1/2" mounting holes

Includes:

• Stud
• Nut
• Lock washer
• Flat washer
• Nylon isolation washer

K4 vs K4A

The K4A uses an SO-239 (UHF female) connection for standard PL-259 coax.

The K4 (non-A) version is designed for ring terminal connections instead.

Why This Matters

The antenna stud is one of the most overlooked parts of a setup, but it directly affects how well your antenna performs. A solid connection here helps avoid common issues like poor SWR, intermittent signal, or long-term wear from vibration.