StarTech ST121UTP VGA Video Extender and Splitter Over Cat5

The StarTech ST121UTP is a VGA extender and splitter that pushes a single VGA signal over standard Cat5 UTP cable to two remote displays at once, eliminating the signal degradation you get when running long analog VGA cable runs directly from a source. Instead of pulling expensive, bulky VGA cable across a building, you run inexpensive Cat5/5e/6 cabling and let the ST121UTP's local and remote transmitter/receiver pair do the work. This is a practical fit for control rooms, lobby displays, digital signage, classrooms, and command centers where a single source (PC, DVR output, or presentation laptop) needs to reach one or two monitors that sit well beyond VGA's practical unassisted range.

Overview

At the core, the ST121UTP is a local unit with 1x RJ-45 port and 1x VGA (15-pin HD D-Sub) input, paired with a remote unit offering 1x RJ-45 and 2x VGA outputs — meaning the local side also carries 2 additional VGA connectors for local pass-through/splitting. That combination lets one VGA source feed a nearby monitor directly while simultaneously extending the same signal to a second display hundreds of feet away over Cat5. For anyone standardizing on structured cabling instead of running dedicated video cable, the ST121UTP turns a Cat5 run into a VGA transport line.

Key Features

• Up to 150m (492ft) max distance: at the lowest supported resolution, this gets a VGA signal from a head-end rack to a display far outside standard VGA cable range — no signal amp needed at the source.
• Resolution-scaled distance table (1024x768 @ 500ft/150m, 1280x1024 @ 300ft/100m, 1440x900 @ 150ft/50m): lets you plan the run length against the resolution you actually need — a lobby sign at 1024x768 can go the full 500ft, while a sharper 1440x900 feed needs to stay inside 150ft.
• Dual VGA output at the remote unit: drives two displays from one extended run, useful for split-screen lobby signage or dual-monitor control room setups without a second cable pull.
• Runs over standard Cat5/5e/6 cabling: avoids the cost and hassle of pulling dedicated long-haul VGA cable — most commercial buildings already have spare structured cabling runs to repurpose.
• Compact footprint (2.4in x 3.3in x 0.8in, 11.8oz): mounts unobtrusively behind a monitor or inside a rack shelf without eating up equipment room space.
• 9V DC / 0.6A power supply, 5.4W consumption: low power draw keeps it easy to run off a small UPS or existing rack power without budgeting extra circuit capacity.
• Operating range 0C to 50C (32F to 122F): rated for standard indoor commercial environments — equipment closets, AV racks, and conditioned control rooms.
• Storage temperature -20C to 60C (-4F to 140F) and 0-80% RH non-condensing: gives installers margin for unconditioned storage or shipping conditions before deployment.
• 2-Year manufacturer warranty: covers the local and remote unit pair for standard commercial deployment life.

Integration & Compatibility

The ST121UTP works as a point-to-point analog VGA transport pair — it isn't networked and doesn't require configuration, which matters for integrators who want a drop-in fix for a distance problem rather than another device to manage on the network. It pairs naturally with existing video conferencing and presentation setups where a source needs to reach displays beyond standard VGA range, and it's a common companion to structured-cabling projects planned alongside network switches and other rack-mounted AV gear. If you're scoping a larger multi-room signage or AV distribution project, a PoE and cabling planning guide is worth reviewing before you commit to run lengths and resolutions. For broader analog-to-digital or signal management needs beyond point-to-point VGA extension, browse the full AV accessories catalog, or check the StarTech catalog for related extenders and splitters in the same connectivity family.

What's in the Box

Package contents were not specified in available manufacturer data for this SKU.

Frequently Asked Questions

Q: What's the maximum distance the ST121UTP can extend a VGA signal?

A: Up to 150m (492ft) at 1024x768 resolution. Higher resolutions reduce the usable distance — 1280x1024 tops out at 300ft (100m), and 1440x900 at 150ft (50m).

Q: Can the ST121UTP drive two monitors at once?

A: Yes. The remote unit provides 2 VGA outputs, and the local unit also includes 2 additional VGA connectors alongside the primary input.

Q: What cabling does the ST121UTP require for the extended run?

A: Standard Cat5 UTP cabling (RJ-45 connectors on both local and remote units).

Q: What's the warranty on the ST121UTP?

A: 2-year manufacturer warranty.

Q: What are the power requirements for the ST121UTP?

A: It ships with a 9V DC, 0.6A power supply and draws 5.4 watts.

Q: What environment is the ST121UTP rated for?

A: Operating temperature of 0C to 50C (32F to 122F) with 0-80% relative humidity, non-condensing — suited to standard indoor commercial installs.

James Everett

The distance-vs-resolution table on the ST121UTP is the first thing I check when someone asks about a VGA extension job: 500ft at 1024x768 but only 150ft at 1440x900. That trade-off drives the whole design decision, so nail down your target resolution before you plan the cable run.

Technical Highlights:

• 150m / 492ft max distance: at 1024x768, this covers most single-building runs from an equipment room to a far wall or lobby without a repeater.
• Dual VGA output at the remote unit: drives two displays off one extended Cat5 run, cutting a second long-distance cable pull out of the job.
• 5.4W power draw off a 9V/0.6A supply: low enough to run off a small rack UPS alongside other AV gear without recalculating circuit load.

Deployment Considerations:

• Because this runs over standard Cat5/5e/6 UTP with RJ-45 termination, it slots into existing structured cabling plant instead of requiring dedicated VGA cable pulls — a real time and cost saver on retrofit jobs.
• Watch the resolution ceiling on longer runs: if the display needs 1440x900, you're capped at 150ft, not the full 492ft rated at 1024x768 — confirm target resolution before quoting cable length.

Good fit for a control room or lobby signage retrofit where a source needs to reach one or two displays beyond VGA's native range over cabling that's already in the wall — ST121UTP turns that into a Cat5 pull instead of a cable replacement project.