The problem with the WireFree unit is it doesn’t have a very long range. It’s advertised as up to 1000 feet, but realistically in most applications it will be around 300 feet. For those people who need the same application at up to a mile or so, that product doesn’t fit the need.

There is another solution, although it is much more expensive and not quite so easy. We have an outdoor intercom callbox that can do something similar.

Our Callboxes with Gate Relay also have the ability to send a warning tone when a change in a Sensor Input is detected. The Sensor Input will respond to an OPEN or CLOSED switch. So you could add a motion detector device that triggers this sensor input, which would tell you that someone is near the Callbox. Since the Callbox does not provide power for the motion sensor you would need to add your own power supply (typically ~+12vDC). You can use any type of security system motion detector as long as it provides relay contact closure or opening.

Now for the audio monitoring part. You’ll need a two-way radio or base-station intercom that has the 2-tone encode feature. This allows you to send a signal to the Callbox to turn on its microphone/speaker so you can “Listen In” to what’s happening around the Callbox for a predetermined time. The microphone will be activated and you will not be able to transmit to the unit during this time (5-30 seconds). After that you can transmit your voice to the Callbox if you want to speak to whoever set off your motion detector.

You can also send a signal to the Callbox to activate a switch output, which is a simple 1-Amp relay contact closure that can be used to OPEN and CLOSE a gate, turn on a video camera, switch on a light, sound an alarm or any other application where remote control of an ON/OFF switch is required. The Callbox can be programmed to alternately OPEN and CLOSE the switch using a single 2-tone code, or can be programmed for separate OPEN and CLOSE 2-tone codes.

So while the Callbox is not quite as easy to install as the WireFree system, it has lots more flexibility and it is a much more commercial-duty system too.

To see the Callboxes visit the following link and look for Callboxes with Gate Relay.

Commercial Intercoms