Viking Long Range Transmitter - LRT-4

Viking Electronics LRT-4 Long Range 4-Button Wireless Transmitter

Overview

The Viking Electronics LRT-4 is a four-button wireless key fob transmitter designed for access control deployments where personnel need to trigger Wiegand-based devices from a distance — up to 400 feet line of sight at 433 MHz. If you're running card readers, gate controllers, or door strikes that accept 26-bit Wiegand input, the LRT-4 drops into that infrastructure without rewiring. Each of the four buttons outputs an independent Wiegand code, letting a single fob control up to four separate access points or relay channels. The LRT-4 (often searched as LRT 4) pairs with Viking's LRR-4 receiver, which handles the Wiegand handoff to your panel.

Key Features

• 400 ft Line-of-Sight Range: Operating at 433 MHz, the LRT-4 reaches up to 400 feet in open-air conditions — practical for parking lots, loading dock gates, and perimeter entry points where a card reader at the door isn't feasible. Note that the SIA Wiegand spec also caps cable runs at 400 feet from receiver to panel, so plan your receiver placement accordingly.
• Four Independent Wiegand Outputs: Each button delivers a distinct 26-bit Wiegand code. That means one fob can arm/disarm a gate, release a door strike, trigger a barrier arm, and activate a secondary relay — four functions, one device in a technician's pocket.
• Rolling Code Security: The LRT-4 uses rolling code plus secure transmission to prevent replay attacks. Someone with a code scanner in the parking lot can't capture and replay a valid credential — critical for any deployment where physical security of the perimeter matters.
• 125 kHz HID-Compatible Proximity Module: The built-in proximity module reads standard 125 kHz HID credentials, so the same fob that works as a wireless transmitter can also present a card credential at a proximity reader. One device covers both use cases — reduces what staff carry.
• CR2032 Battery, Up to 500,000 Presses: A standard coin cell rated for half a million button activations. For a technician pressing the fob 10 times a day, that's roughly 137 years of battery life — practically maintenance-free. Buttons themselves are rated to 1 million mechanical activations.
• 26-Bit Wiegand Output Format: The industry-standard format supported by virtually every access control panel on the market. No proprietary translation layer needed — the LRR-4 receiver presents clean Wiegand data to your panel's reader port.
• Compact Key Fob Form Factor: At 2.5" x 1.4" x 0.52" and 0.1 lb, it clips to a keychain without bulk. Field personnel carry it alongside standard keys — no separate credential holder required.
• NEMA 4/4X Enclosure Rating: Rated for hose-directed water and corrosion resistance (4X). Deploy in washdown environments, outdoor exposure, or coastal facilities without worrying about moisture ingress damaging the fob.

Integration and Compatibility

The LRT-4 is the transmitter half of Viking's LRR-4/LRT-4 long-range wireless system. The companion Viking Electronics access control LRR-4 receiver handles the 433 MHz signal and converts it to 26-bit Wiegand output for your panel. The receiver requires 12 VDC nominal at 120 mA — a standard access control power supply covers this. Maximum Wiegand cable run from receiver to panel is 400 feet per SIA specification, so position your receiver within that distance of the panel's reader port. The 125 kHz HID proximity module means the LRT-4 also works at standard access control proximity readers — useful in mixed-credential environments where some doors have readers and others don't. For larger deployments, review your door controller channel count before assigning all four fob buttons to separate access points.

Frequently Asked Questions

Q: What receiver does the LRT-4 require?

A: The LRT-4 is designed to work with the Viking Electronics LRR-4 long-range receiver. The LRR-4 accepts the 433 MHz rolling code signal and outputs 26-bit Wiegand data to your access control panel.

Q: What is the maximum range of the LRT-4?

A: Up to 400 feet line of sight. Obstructions, building materials, and RF interference will reduce effective range in real installations.

Q: Is the LRT-4 compatible with HID card readers?

A: Yes. The built-in 125 kHz proximity module is HID-compatible, so the fob can present a credential at standard HID proximity readers in addition to operating as a wireless transmitter.

Q: How long does the battery last in the LRT-4?

A: The CR2032 coin cell is rated for up to 500,000 button presses. Under typical use the battery is effectively maintenance-free for years of daily operation.

Q: What output format does the LRT-4 use?

A: Standard 26-bit Wiegand — the same format used by the vast majority of access control panels and readers. No special adapters or converters needed.

Q: What is the environmental rating of the LRT-4?

A: NEMA 4 and NEMA 4X, meaning it resists hose-directed water and corrosion. Suitable for outdoor carry and washdown environments.

Ted Perry

The spec I keep coming back to on the LRT-4 is the 433 MHz operating frequency paired with a 400-foot line-of-sight range — that combination consistently outperforms the 315 MHz fobs I see on cheaper systems in parking and yard applications. If you're commissioning a gate or vehicle barrier where the operator stays in a booth or vehicle and can't reach a wall reader, this is the transmitter that actually covers the geometry without a repeater.

Technical Highlights:

• Rolling Code at 433 MHz: Prevents replay attacks at up to 400 ft — relevant when the signal crosses a public parking area where someone could sit with an SDR and a laptop.
• Four-Button / Four-Code Design: Each button is a separate 26-bit Wiegand credential. On a four-door site, one fob can handle the whole facility — fewer credentials to manage in the panel.
• CR2032 / 500,000-Press Rating: In a busy warehouse where gate operators press the fob 50 times a day, you're still looking at roughly 27 years of battery life. This is not a call-back item.

Deployment Considerations:

• The SIA Wiegand spec caps cable at 400 feet from receiver to panel — if your panel room is more than 400 feet from the optimal receiver mounting point, you'll need a Wiegand extender or to reposition the panel's reader port input.
• The 433 MHz band is shared with other ISM devices. In dense RF environments (large warehouses with RFID infrastructure, or sites near industrial equipment), verify range in the field before finalizing receiver placement — the 400-foot spec is line-of-sight, not through steel racking.

The LRT-4 is a strong fit for vehicle yard access, loading dock gate control, and any site where personnel can't dismount or approach a fixed reader — the four-button layout and HID proximity compatibility mean it can replace both a fob and a card in the same credential for most standard 26-bit panels.