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vhfBridge.
Wireless module for connecting an Ajax system to third-party VHF transmitters
Another route for the alarm to reach the operator.
vhfBridge Jeweller connects an Ajax system to a separate third-party VHF transmitter. It receives system events from the hub and passes selected signals through eight configurable outputs, providing an agreed primary or additional reporting path to the monitoring station. The transmitter, receiving network, power budget and output mapping are planned together.
Key features. At a glance.
Additional VHF path1
Events to the monitoring station
Eight potential outputs2
Configurable event signals
Two signal polarities
High or low potential
0.5–255 seconds
Adjustable pulse duration
Pulse or bistable
Event and state signalling
Up to 1,800 m3
Jeweller radio in open space
100–240 V AC
Main power supply
Up to 2 A4
Transmitter power output
4 or 7 Ah5
Compatible 12 V backup battery
Up to 75 hours6
Specified backup maximum
Two tampers
Cased model protection
Cased or board-only7
Check the selected configuration
- 1Requires a separate compatible VHF transmitter and monitoring receiver.
- 2These are voltage-signalling outputs, not dry-contact relays.
- 3This is the hub-to-module range. VHF distance depends on the separate transmitter, terrain and receiving network.
- 410.5–15.5 V DC; check the transmitter’s electrical requirements.
- 5Battery is not included.
- 6With a 7 Ah battery; actual duration depends on the transmitter load and activity.
- 7The board-only version needs a suitable enclosure.
Specifications shown for vhfBridge Jeweller. Ajax product information ↗ · vhfBridge Jeweller specifications ↗
Add a radio path to the monitoring station.
Ajax events through a separate VHF transmitter
The hub sends events to vhfBridge over Jeweller. The module then activates the wired inputs of a compatible third-party VHF transmitter, which reports to the monitoring station.
vhfBridge is not itself a VHF transmitter. The separate transmitter, receiving network and monitoring-company setup determine the reporting range.
Match the transmitter’s inputs.
Eight configurable potential outputs
Connect a compatible VHF transmitter with the required relay-input interface. Configure which event each of the eight potential outputs reports.
These are voltage-signalling outputs, not eight dry-contact relays. Match polarity and electrical requirements with the transmitter’s documented inputs.
Map each event to a clear signal.
Polarity, pulse and state
Choose high-potential or low-potential output behaviour. In pulse mode, set a duration from 0.5 to 255 seconds; bistable operation follows the selected state.
Available event mappings and modes depend on hub software. Configure and test both event and restoration at the monitoring station.
Plan the reporting path and its limits.
A primary or additional reporting channel
VHF reporting can operate alongside the hub’s internet connection or serve the agreed primary monitoring path. Loss of internet does not have to remove this separate alarm channel.
VHF event signalling does not replace internet access for Ajax apps, configuration, photos or cloud features. Delivery depends on the complete transmitter and receiver installation; no universal kilometre range is guaranteed.
Include the transmitter in the backup calculation.
Mains and a separate backup battery
The module uses 100–240 V AC and supports a separately purchased 12 V, 4 or 7 Ah backup battery. Its output can supply a compatible VHF transmitter at 10.5–15.5 V DC, up to 2 A.
Up to seventy-five hours is the stated maximum with a 7 Ah battery. Actual duration depends on transmitter consumption and activity. Neither the battery nor the VHF transmitter is included.
A secure link to your system.
Jeweller communication
Encrypted two-way communication carries commands, alarms and device status between the device and its compatible Ajax hub or assigned range extender.
Up to 1,800 m in open space. Walls, metal and other obstacles reduce usable coverage. Check signal strength at the installation position and use equipment for the same radio-frequency region.
Choose the right supplied configuration.
With or without the casing
The product is supplied in versions with an enclosure or as a board without one. Check the selected version and provide a suitable installation enclosure where required.
The listed cased model is for indoor use at −10°C to +40°C with IP40 protection. A bare board must not be treated as a weatherproof finished device.
Monitor the module as part of the system.
Enclosure and radio supervision
The cased configuration has two tampers for lid opening and removal from the wall. The hub authenticates the module and supervises its Jeweller connection.
The nominal 36-second radio-loss report depends on polling settings. Check any required transmitter and receiver supervision with the monitoring provider.
Prove the path all the way to the operator.
Install, map and test
An installer mounts the module, connects the compatible VHF transmitter, pairs vhfBridge by QR code and maps each output in Ajax apps. Send test events and restorations through to the monitoring station.
Also test mains loss, battery operation and the agreed behaviour when internet or radio communication is unavailable. Use the exact manual for electrical connections.
Find the right VHF interface.
Plan the interface between an Ajax system and a separate VHF alarm transmitter. Choose the cased or board-only version for the installation.
Check the VHF connection →Every detail, in one place.
Communication
- Jeweller communication technology
- Two-way system communication for the functions specified for this model.
- Radio communication range
- up to 1,800 m Between the module and a hub (or a range extender) in an open space.
- Encrypted communication
- Encrypted device communication.
- Frequency hopping
- To prevent radio interference and jamming.
Power supply
- Main
- 100–240 V, 50/60 Hz
- Backup
- 12 V⎓ battery, 4 or 7 Ah A backup battery is not included. The battery should have a full charge cycle of up to 30 hours.
- Calculated battery life
- up to 75 hours
- VHF transmitter power
- 10.5–15.5 V⎓, up to 2 A
Key features
- Control via smartphone
- Users can set up the module configurations and receive notifications in Ajax apps.
- Number of potential outputs
- 8
- Compatibility with third-party VHF radio transmitters
- Any VHF transmitter with relay inputs can be connected to vhfBridge Jeweller
- Adjustable pulse duration
- from 0.5 to 255 s
- Operation modes
- pulse; bistable
- Output types
- high potential (positive trip); low potential (negative trip)
Sabotage protection
- Protection against spoofing
- device authentication
- Tamper alarm
- 2 tampers Notifications on attempts to detach the device from the surface or open the front lid.
- Communication loss detection
- after 36 s Detection time depends on the Jeweller or Jeweller/Fibra settings.
Enclosure
- Dimensions
- 196 × 238 × 100 mm
- Weight
- 840 g
- Operating temperature range
- from −10 °C to +40 °C
- Operating humidity
- up to 75%
- Protection class
- IP40
What’s in the box
- vhfBridge Jeweller
- Power cable
- 12 V battery connection cable
- Installation kit
- Casing
- Quick start guide
For your installation
- Selected as part of an installer-reviewed security or automation project.
- Confirm the supported control panel, device software and regional radio version; test coverage at the final installation position.
- The device is designed for indoor use only.
- Choose the exact version: sensing, power, casing, pack size or interface details can differ between the listed models.
Find the right protection.
MultiTransmitter Jeweller
MultiTransmitter brings wired detector signals into Ajax; vhfBridge sends system events onward.
SpeakerPhone Jeweller
A supported monitoring setup can use SpeakerPhone for direct voice contact with the property.