Application for access to the Enterprise API of the Ajax system
We provide access to the Enterprise API to large security and service companies already serving or planning to serve thousands of Ajax security systems.
vhfBridge
Module for connecting Ajax security systems to third-party VHF transmitters
Module with
a casing
a casing
3 249
UAH
Recommended price
VAT included
Module without
a casing
a casing
2 699
UAH
Recommended price
VAT included
Instant alarm transmission without Internet
vhfBridge is a transponder that provides a hub with an additional channel to communicate with a monitoring station. With vhfBridge you can use Ajax systems in cities where Internet connection is unstable, in nature reserves, mountain and desert areas.
Alarms and events of the system are transmitted via VHF radio waves over tens of kilometres1. vhfBridge can be used as a primary or a backup communication channel.
Reliability and versatility by design
You can buy vhfBridge without a casing
You can connect any VHF transmitter with relay inputs to vhfBridge
Elaborate autonomy
You can build in a 7 Ah backup battery inside a vhfBridge casing. It will feed a VHF transmitter with up to 2A current consumption. Therefore, the transmitter doesn't need to have a separate battery, which makes maintenance less frequent.
In case of a power outage at a facility, the transponder and the transmitter operate on a backup battery for up to 75 hours4 while still transmitting events to a central monitoring station.-
![]()
Up to 75 hours4 of autonomous operation -
![]()
Place for a 7 Ah backup battery
Adjustable signalling
Get only events you need. You can configure each vhfBridge output in the Ajax app: set an event or disable it.
Uncompromised security of communication
vhfBridge communicates with a hub via an encrypted Jeweller radio protocol. It guarantees continuous interaction of all security system devices. The radio protocol uses frames to synchronize device communication sessions, authentication to prevent forgery, and encryption to protect against data theft.
Connection with a hub at a distance of up
to 1,800 meters
to 1,800 meters
Alarm transmission within
0.15 seconds
0.15 seconds
Hub ping interval
from 12 seconds
from 12 seconds
Hassle-free installation
Similar to other Ajax devices, vhfBridge connects to a hub in the app by scanning a QR-code. The transponder casing has perforated areas for more organized wiring. Outputs are configurable with Ajax apps for smartphones and computers.
-
![]()
Adding to the system by scanning a QR-code -
![]()
Mounting on a wall -
![]()
Connecting of a VHF transmitter -
![]()
Setting up with an app
Tech specs
Color
White and black
Classification
Transponder for communication with the monitoring station via a VHF radio transmitter
Installation
Indoors
Number of potential outputs
8
Output types
Normally open
Transmission types
Pulse and bistable
Recommended VHF transmitters
Hawk VHF Alarm Transmitter from FSK Electronics
TX750C from RDC
TR-41 from Puper
TX750C from RDC
TR-41 from Puper
Compatible with Ajax central units
Compatible with Ajax range extenders
+
Compatibility with third-party VHF radio transmitters
Support for photo verification of alarms
No
Primary power supply
100–240 V, 50/60 Hz
Backup power supply
12 V DC, up to 75 hours of power for a transponder and a transmitter
Supported battery type
12 V battery with a full charge cycle of up to 30 hours.
The maximum battery size installed in the casing should be 150 × 64 × 94 mm
The maximum battery size installed in the casing should be 150 × 64 × 94 mm
Recommended battery type
12 V battery with a capacity of 4 Ah or 7 Ah
Backup battery is not included in the set
Backup battery is not included in the set
VHF transmitter power
12 V DC, 2 A
Anti-sabotage
Protecting against forgery
Jamming notifications
Tampers against opening and removal
Backup battery
Jamming notifications
Tampers against opening and removal
Backup battery
Jeweller radio protocol
Communication range — up to 1,800 meters in a line of sight
Two-sided communication between devices
Operating frequencies: 868.0–868.6 MHz
Auto-regulated radio signal power: ≤ 25 mW
Blocking encryption based on the AES algorithm
Detector ping interval: 12–300 seconds
Frequency hopping
Learn more about Jeweller
Two-sided communication between devices
Operating frequencies: 868.0–868.6 MHz
Auto-regulated radio signal power: ≤ 25 mW
Blocking encryption based on the AES algorithm
Detector ping interval: 12–300 seconds
Frequency hopping
Learn more about Jeweller
Maximum radio signal power
≤ 25 mW
Protection class
IP50
Operating temperature range
From −10°C to +40°C
Operating humidity
Up to 75%
Overall dimensions
196 × 238 × 100 mm (with casing)
145 × 89 × 51 mm (without casing)
145 × 89 × 51 mm (without casing)
Weight
840 g (with casing)
165 g (without casing)
165 g (without casing)
Warranty
Complete set
vhfBridge
Power cable
12 V battery connection cable
Installation kit
Casing (depends on a set)
Quick start guide
Power cable
12 V battery connection cable
Installation kit
Casing (depends on a set)
Quick start guide
Lifespan
10 years
1
The distance depends on the transmitter, the terrain, and the weather. The maximum range varies in each particular case.
2
A backup battery is not included in the set.
3
vhfBridge can be sold without a casing.
4
When using a 7 Ah battery.