This wireless intercom review will help you make an intelligent choice on choosing a wireless intercom system. There are a limited number of wireless intercoms on the market so choosing one is not as difficult as choosing some other type of consumer product. There are really only three wireless intercom systems that are available.
Powerline Carrier Intercom
Portable Baby Changing Table
One wireless intercom is not truly wireless. It transmits and receives over the power lines of your house. Westinghouse makes one of these. Radio Shack also has one too but they call it an FM (frequency modulation) intercom (I believe Westinghouse private labels the Radio Shack intercom so it's the same product). It transmits and receives on FM frequencies, but it does so over the power lines.
These power-line carrier intercoms can work well but they frustrate more than half of the people who use them. One of the problems with these systems is with the way your house is wired. There's 220 volts coming in to your house, and that 220 is divided into two phases of 110 volts each; half your house will be wired on one phase and half on the other. The problem is that the FM signal does not usually jump across the phases, or if it does, it doesn't do it very well. So the intercoms may work fine in half your house and not at all, or poorly, in the other half.
The other problem with these power-line carrier intercoms is that you may have equipment plugged in that causes interference with the FM signal. Microwaves may be one of the worst offenders. These devices may make the intercom unusable. While these intercoms are cheap and you may try them to see if they work in your house, they are not recommended for commercial environments. There are just two many devices in an office or industrial environment that render them useless.
900 Mega Hertz Wireless Intercom
The other system on the market is the WireFree 900MHz Wireless Intercom System. As the name says, it transmits wirelessly in the 900MHz frequency range. This is the only true wireless system on the market. It is not the only one that transmits wirelessly through the airwaves, but it is the only one that is battery powered. So not only does it not communicate through your house or business wiring, it is not even plugged in unless you choose to purchase the optional power adapter.
The WireFree system is unique in that it has multiple low-cost components that no other wireless intercom system has. It has portable intercom units that sit on the surface of a desk, table, or countertop. There are two styles of this unit with one being called the WireFree Extreme Range system. It transmits and receives the same distance as the non-extreme range unit. Both have a maximum range of 1000 feet, but you are more likely to get in the 300 foot range depending on environment. Both units have the same feature set.
The WireFree system has a water-resistant outdoor doorbell intercom that can be used at your front door to talk to people there. The nice thing about this unit is once the people at your door press the button, they can talk hands free.
There is also a water-resistant outdoor intercom that can be used in any outdoor installation. This intercom requires button presses for every transmission. You can hang it on the wall or also put rubber feet on this unit and use it inside if you want. The nice part is that it only has one large button which makes it easy to use.
The WireFree system also has a flush mount intercom that can make your installation more custom looking. It requires cutting a hole in your wall, but it is battery powered too so no wiring is required. The battery life in all the WireFree units is 1 to 2 years so they don't require a lot of battery changing.
The WireFree system has a Monitor and VOX feature that not all wireless intercoms have. Monitor is like a baby monitor mode. The difference is that it does not continuously monitor. Its microphone only turns on when it detects sound that's loud enough to turn on the microphone. There are three different sensitivity settings to trigger the microphone, but even at its most sensitive setting, it won't work well for faint voices more than a couple of feet from the microphone. The downside of using the Monitor mode for some applications is that it sounds a tone on the receiving side every time the microphone is activated. If you were using this to monitor children, this would get irritating pretty fast.
If you put a WireFree unit in VOX mode, whenever someone from another unit calls the unit in VOX mode, they can respond hands free without pressing the Talk button. One problem that is shared with two-way radios that have VOX is that there is a slight delay in transmission while the VOX circuitry turns on the transmit microphone. Experienced radio operators know how to overcome this by repeating the first word or two, but for the average person, this delay is a little frustrating.
One unique feature of the WireFree system is its ability to do private conversations. Units have to be "taught" to talk with each other. Once this is done, even if your neighbors have the same unit, they can't listen or talk to yours. Also when you broadcast a page to all units, the WireFree system will set up a private conversation between the broadcaster and the person responding so all other units won't hear the conversation.
MURS Wireless Intercom
Yet another wireless intercom system is not so much of a system from one manufacturer as it is a compilation of wireless intercoms and two-way radios. This "system" is based on compatible products in the MURS radio frequency. MURS stands for Multi-Use Radio Service and is a two-way radio service consisting of five frequencies in the VHF (Very High Frequency) spectrum. Unlike most frequencies in the VHF range, MURS does not require an FCC license to operate.
Even though there are only 5 channels, each channel can choose between one of 38 "quiet codes" or sub-channels to keep you from hearing conversations of other users on that channel. You will only hear conversations from radios set to the same channel and quiet code as your radio. In most areas the MURS frequencies are very lightly used so you won't find a lot of competition for the airwaves.
The biggest benefit of MURS is the range it offers. Some manufacturers claim a range of four miles. Of course this range is a line of sight with no obstructions between intercoms. Range can even be increased with these intercoms by adding an external high-gain antenna on top of your house, business, or even car if you use a unit there.
What's nice about MURS is that you can get handheld two-way radios, commercial-duty base station and outdoor intercoms/callboxes, and even motion detectors that transmit a verbal alert message to other MURS devices. For business, industrial, or commercial applications a MURS system excels since it can overcome a lot of interference and obstacles these applications present.
If you need a wireless PA (public address) system, there is a wireless PA device that works with all the MURS radios. For retail business that services customers directly, there is even a wireless MURS device that enables customers to press a button and call for assistance via a transmitted recorded message.
Since any manufacturer can create a MURS wireless device, choosing a MURS system keeps you from being locked in to whatever products a particular manufacturer chooses to offer.
Whichever wireless intercom system you choose, they give you convenience and security that you can install quickly with no hassle.