Viking Single Line Loud Ringer and Door Chime - SR-1

Viking Electronics SR-1 Single Line Loud Ringer and Door Chime

The Viking Electronics SR-1 is a single-line loud ringer and door chime designed to monitor analog telephone lines — including PABX and KSU station ports — and produce a high-output audible alert when a ring signal is detected. At 90 dB at one meter, the SR-1 cuts through ambient noise in warehouses, machine rooms, loading docks, and open-plan offices where a standard phone handset speaker simply won't be heard. If you're wiring a facility where personnel need to know a call is coming in without being tethered to a desk, this is the device built for that job.

Overview

The SR-1 interfaces directly with an analog phone line — a PABX or KSU extension port — and generates a loud ringing tone or door chime signal when ring voltage is detected. It ships with a UL listed 120V AC/13.8V AC 1.25A adapter, so there's no separate power supply to source. The compact 5.5" x 4.5" x 1.7" enclosure mounts on a wall or surface, and the 10-position cage clamp terminal block makes field wiring straightforward without requiring soldering or crimping. Explore the full Viking Electronics line for companion devices including door controllers, entry phones, and call boxes.

Key Features

• 90 dB Output at 1 Meter: That's roughly the volume of a power drill at close range — loud enough to be clearly audible across a noisy production floor or in a mechanical room with HVAC running. Standard desk phones top out around 70–75 dB; the SR-1 is designed for environments where those are simply inaudible.
• Analog Line Monitoring (PABX/KSU): Connects directly to a PABX station port or KSU extension without requiring additional interface hardware. If your facility runs an existing analog PBX, the SR-1 integrates without a converter. No IP infrastructure required — straightforward for legacy telephony environments.
• 8-Ohm Speaker Impedance: Standard 8-ohm output means the SR-1 can drive a compatible external speaker if you need sound projection beyond what the built-in speaker provides — useful in larger rooms or hallways where a single point of sound isn't sufficient.
• 10 Cage Clamp Screw Terminals: Cage clamp terminals grip wire firmly without the creep issues that plague standard screw-only terminals over time. For a telephone accessory that may go years between service visits, this is the right termination type.
• UL Listed Power Adapter Included: The included 120V AC/13.8V AC 1.25A adapter carries UL listing, which matters for installations subject to code review or insurance requirements. No need to spec or source a separate supply.
• Compact Wall-Mount Enclosure: At 5.5" x 4.5" x 1.7" (140mm x 115mm x 43mm), the SR-1 fits in tight utility spaces. The 1.5 lb shipping weight means no special mounting hardware is needed for standard drywall or metal stud installations.
• Operating Temperature 32°F to 90°F (0°C to 32°C): Rated for standard indoor commercial environments. This is not a unit for unheated outbuildings or freezer warehouses — if the space drops below freezing or the ambient heat exceeds 90°F regularly, plan accordingly. For commercial intercom and alerting deployments in conditioned spaces, it's well within range.
• 5% to 95% Non-Condensing Humidity Tolerance: Handles the humidity swings typical of loading dock vestibules, break rooms, and utility corridors without requiring a sealed enclosure — as long as condensation isn't forming on the unit.

Integration and Compatibility

The SR-1 is purpose-built for analog telephony infrastructure. It monitors for ring voltage on a standard analog line — the type delivered by a PABX or KSU station port — and triggers its loud ringer accordingly. It does not require configuration software, a network connection, or IP addressing. If your facility uses a PBX telephone system with analog station ports, the SR-1 wires in directly at the terminal block. For facilities transitioning to VoIP, note that the SR-1 requires an analog signal; you'll need an FXS port or analog telephone adapter (ATA) to interface with a SIP-based phone system. Pair this with Viking's door entry and access control products for a complete front-of-facility alerting solution — see the broader door entry and intercom category for compatible devices.

Frequently Asked Questions

Q: What type of phone line does the SR-1 work with?

A: The SR-1 is designed to monitor analog telephone lines, specifically PABX and KSU station ports. It detects ring voltage on an analog line and activates the loud ringer. It does not natively support VoIP or SIP lines — an FXS port or ATA adapter would be required to use it with a VoIP system.

Q: How loud is the SR-1, and is that enough for a noisy industrial environment?

A: The SR-1 produces a maximum of 90 dB at one meter. For context, that's comparable to a power drill or heavy truck traffic at distance — significantly louder than a standard telephone handset. For most commercial and light industrial environments, 90 dB is sufficient. In very high-noise environments (above 85–90 dB ambient), additional units or external speaker wiring should be considered.

Q: Does the SR-1 require a separate power supply?

A: No. The SR-1 ships with a UL listed 120V AC/13.8V AC 1.25A adapter. You need a standard 120V AC outlet within reach of the installation point — no separate power supply to source or specify.

Q: Can the SR-1 drive an external speaker?

A: The SR-1 has an 8-ohm speaker impedance, which is the standard impedance for many commercial speakers. An external 8-ohm speaker can be connected to extend coverage beyond the built-in speaker's range — useful for larger rooms or hallways.

Q: What are the environmental limits for the SR-1?

A: The SR-1 is rated for 32°F to 90°F (0°C to 32°C) operating temperature and 5% to 95% non-condensing humidity. It is designed for conditioned indoor commercial spaces. It is not suitable for unheated or outdoor installations where temperatures may fall below freezing or exceed 90°F.

Q: How is the SR-1 wired?

A: The SR-1 uses 10 cage clamp screw terminals for all connections. Cage clamp terminals provide a secure, vibration-resistant wire grip without soldering. Standard field wiring tools are sufficient — no special crimping equipment required.

Karl Wilson

The SR-1 (often searched as SR 1) is one of those workhorses I keep specifying for facilities that run legacy analog PBX infrastructure and have areas where nobody can hear a standard phone ring. The 90 dB output at one meter isn't marketing copy — that's a measured sound pressure level that genuinely clears ambient HVAC and production noise in most light industrial settings. What I like about this unit is that it doesn't pretend to be more than it is: wire it to an analog station port, plug in the included UL listed adapter, and it works.

Technical Highlights:

• 90 dB @ 1 Meter: Enough to be heard across a 5,000–10,000 sq ft open floor in typical commercial ambient noise. If your environment runs consistently louder than that, plan for multiple units or external speaker extension via the 8-ohm output.
• 10 Cage Clamp Terminals: More reliable long-term than standard screw terminals in environments with vibration or thermal cycling — the clamp maintains grip as wire expands and contracts. A small detail that matters in a device that may not be touched again for five years.
• UL Listed Adapter Included: Eliminates a line item in your BOM and satisfies inspectors who want to see listed components throughout. The 120V AC/13.8V AC 1.25A spec is within standard commercial outlet capacity — no circuit engineering required.

Deployment Considerations:

• The SR-1 requires an analog ring signal — PABX or KSU station port. If the facility is on a fully hosted VoIP or SIP platform with no analog ports, you'll need an FXS gateway or ATA before this device will see a ring signal. Budget for that interface if the phone system is all-IP.
• Operating ceiling is 90°F (32°C). Mechanical rooms near boilers, server rooms without cooling, or sun-exposed utility closets can easily hit or exceed that. Verify ambient temps at the install location before committing to placement — this is an indoor, conditioned-space device.

Best fit: manufacturing and distribution facilities with an analog PBX extension in a noisy bay or dock area where personnel need call notification without a phone handset nearby. It's also a clean solution for front-door chime notification in commercial office lobbies tied to analog intercom lines.