40 Foot DB9 Male to Female RS232 Extension Serial Cable - Flexible

In this review the 40 ft DB9 male to female RS232 extension cable is presented as a practical solution for anyone needing to lengthen existing serial connections without redoing equipment wiring. The reviewer found it especially useful for extending RS-232 peripherals and adding a monitor or serial device when the original cable falls short. Built with 24 AWG shielding and metal hoods, it prioritizes a secure physical connection and interference protection, so the main reason to buy is reliable, tangle-free extension of legacy serial links over a long run.

Key Features

• Male to female DB9 connectors: Provides a straightforward extension for existing RS-232 cables so devices can be repositioned without rewiring.
• 40 ft length: Gives ample reach for most office or industrial setups, allowing peripherals to be placed at greater distance from hosts.
• 24 AWG shielded cable: Reduces EMI and RFI to keep serial communications stable across the longer run.
• Metal hoods with thumbscrews: Ensure a secure mechanical connection that resists accidental disconnection during use.
• Straight-through wiring: Maintains pin-to-pin compatibility with standard RS-232 devices for simple plug-and-play extension.
• Grey PVC jacket: Offers a neat, durable outer layer that fits common office and equipment environments.

Who It's For

This cable is for technicians, office IT staff, and hobbyists who work with legacy serial equipment and need a dependable extension without altering existing hardware. It suits setups where devices must be moved farther apart, such as adding a monitor, connecting serial consoles, or relocating peripherals in a workspace.

Those who should look elsewhere include users needing active signal conversion (for example USB-to-serial or DB9-to-HDMI adapters), or extremely compact cable runs where a 40 ft length would be impractical. It is a passive extension and assumes compatible RS-232 endpoints.

Pros & Cons

Pros

• Robust metal connector hoods and thumbscrews make connections secure and easy to tighten.
• 24 AWG full shielding helps guard against EMI/RFI for more reliable serial communication over distance.
• Straight-through DB9 wiring ensures broad compatibility with standard RS-232 devices without reconfiguration.

Cons

• The cable is passive and will not convert signals or provide active buffering for very long runs in electrically noisy environments.

Specifications

Connector type	DB9 male to DB9 female
Length	40 ft
Conductor size	24 AWG
Shielding	Fully shielded (EMI/RFI protection)
Jacket	Grey PVC
Hoods	Heavy duty metal with thumbscrews
Wiring	Straight-through pin wiring

Our Verdict

The 40 ft DB9 extension is a solid, no-nonsense choice for extending RS-232 connections where distance and interference protection matter. It offers good build quality and shielding for the price and is best for users who need a passive, compatible extension rather than signal conversion or active line conditioning. For straightforward serial extension it represents sensible value.

Frequently Asked Questions

Will this cable convert serial to USB?
No. This is a passive DB9 male-to-female RS-232 extension and does not provide USB conversion or signal adaptation.

Are the pins cross-wired or straight-through?
The cable is wired straight-through with pin-to-pin continuity for standard RS-232 compatibility.

Does the shielding prevent interference?
The 24 AWG fully shielded construction reduces EMI and RFI, improving reliability in typical office and light industrial environments.