When looking for a two-way radio you’ll come across terms like UHF and VHF. UHF stands for Ultra High Frequency and VHF stands for Very High Frequency. These are different bands of radio frequencies with UHF being in the 300 MHz and 3000 MHz range and VHF in the 30 MHz and 300 MHz band.

The question most people have is which is better, UHF or VHF. The answer is neither and both. It depends on how and where you want to use them.

To give you a quick and dirty generalization, if you are planning on using your two-way radios mainly inside buildings, then UHF is likely the best solution for you. If you are mainly using your two-way radios for communication outside, then VHF would be a good choice. Either radio technology can work for you if you don’t really have a long range to cover. In that case you may want to choose VHF for it’s lower cost.

There’s a much more detailed article on UHF versus VHF you can read by clicking on the link in this sentence.

You can also find two-way radios at http://www.intercomsonline.com

Several times we have had people contact us for an intercom system they could
use as an elevator call system. These are mostly construction projects that have
an elevator operator for a manually controlled elevator. They want an intercom
system that can be used to call the elevator operator from any floor.

We have tried the WireFree Outdoor Intercoms in this application, but they don’t
usually penetrate the concrete that’s around an elevator shaft. The MURS 4-mile
Range Intercom would have the range needed but it’s not battery powered, which
is a requirement. Plus it doesn’t wall mount.

What can be used is the MURS Outdoor Customer Service Callbox . This Callbox is normally used in stores so a customer can call for assistance. When its button is pushed, it sends out a prerecorded message to a handheld two-way radio. You can program the recorded message yourself. So each floor would have a message something like: “Floor 3″.

When someone presses the button, a light on the unit lights to indicate the message has been sent. The elevator operator then goes to that floor and hits a reset button on the bottom of the unit to turn the light off.

These Callboxes are battery powered and the batteries last up to a year so this can be the perfect solution to this problem.

When installing a wireless PA system, the single biggest expense is usually the wiring. Its not the cost of the wire, but rather the installation cost. As in the diagram below, there is often concrete or asphalt between locations where the public address system is to be installed. Trenching through that is both expensive and messy. The expense doesn’t stop once you get inside the building and you have to start running wires through walls too.

Going with a wireless PA system instead can save you money. The PA system consists of receiver unit with antenna that receives transmissions, amplifies them, and then sends them to an attached PA horn speaker. Up to two speakers can be attached to a single receiver. As shown in the diagram below, each zone can be set to different volume levels depending on the environment.

One benefit of a wireless PA system over a wired system is that you can use handheld two-way radios to make pages. So no matter where you are, you can page someone or make announcements. Even if you are up to two miles away!

One more benefit is that these units can also be programmed to receive transmissions from NOAA Weather Radio so employees will know instantly when bad weather is approaching.

A wireless PA system and intercoms and radios that communicate with it are available at http://www.intercomsonline.com.

The first thing you want to determine when you’re looking for office wireless intercom systems is what application will it be used for. Many times when we talk to people looking for a wireless intercom system they want the same functionality they will get from a telephone system. Meaning they want to be able to call specific offices or desks like they could with a telephone system. Unfortunately a wireless intercom really doesn’t fit this application well.

A phone system has the advantage of being able to assign extensions that people can dial and the phone system routes the call. Wireless intercoms don’t have that capability. They do have some wireless channels that you could in theory use to call individual offices, but if someone changes off of their assigned channel to “call” you on your channel, and after the call they don’t change back, no one will be able to contact them. Wireless intercoms work best for broadcasting to everyone.

The other thing you need to decide is what frequencies the intercom needs. There are intercoms in the 900MHZ, VHF and UHF frequencies. This essentially comes down to the coverage you need. 900MHz will only provide a few hundred feet of range. VHF intercoms have more power and lots more range, but they do not handle the interference cause by a building’s construction as well as UHF intercoms do. However, all of these types of intercoms have applications they fit well in an office so there is no easy answer on the best one.

You can find more information on wireless intercoms systems at http://www.intercomsonline.com

Since the Virginia Tech tragedy colleges have been looking for emergency alert systems to increase the safety of their students. They need a way to instantly notify students of an impending danger.

Installing a wired notification system could cost 100’s of thousands of dollars and require trenching that tears up the campus and cutting holes in walls of the buildings.

There are also cell phone notification systems where all students are called on their cell phones. These work well as long as the cell phone is turned on, the battery isn’t dead from too much usage, and it is not in use during the time of the emergency. Also, professors usually require their students to turn off cell phones while in class and for large populations it can take a long time to call that many cell phones.

At IntercomsOnline.com we have various products that can be put together as an emergency mass notification system. These solutions are wireless which reduces the expense of installation and it eliminates the mess of trenching and cutting holes in walls.

Our MURS Wireless PA System can quickly and easily be placed around select locations of the campus. It consists of an emergency alert radio receiver that allows you to use a base station intercom or mobile 2-way radio to deliver voice messages directly to an attached PA speaker from up to 2 miles away.

You can also enable the MURS Wireless PA to receive local NOAA weather radio emergency broadcasts from the National Weather Service and play them over the loudspeaker. This will keep everyone aware of severe weather approaching. This feature requires setting the unit to your local weather alert frequency.

If you have an application that doesn’t require a loud volume, the MURS Commercial Intercom may work for you. It has the capability of adding an external speaker that can be used to increase the volume of this base station intercom, especially if you add an amplified speaker. This intercom can be programmed for only one channel so students can’t change it. Not only can students hear emergency messages, they can use it to report dangerous situations. Or another option is to install the intercom above the ceiling and just run a wire to a speaker.

You can also place the MURS Callbox XT Outdoor Intercom in strategic locations so that students or staff can alert campus security staff of danger that they can then report over the emergency alert system.

If you want to transmit a prerecorded message, a transmitter device with a panic button is available. One push of a button will send the notice to everyone.

All these products work on the unlicensed MURS radio frequency, but they can also be programmed to work with any existing UHF or VHF radios you may have.

Using these products enables you to quickly set up a college emergency alert system faster than any other solution. All these products are available at http://www.intercomsonline.com.

The day of the actual event for an event coordinator is a busy day and communication is of the utmost importance to pull the event off successfully. That’s where a good communication system can help.

If the event is in a large venue then handheld two-way radios are required. Usually there is a “command central” or a base office where the coordination is orchestrated. A base station intercom such as the MURS 4 Mile Range Intercom is a good choice for communicating with the two-way radios. The base station sits on top of a desk or table.

If radio communications need to remain silenced, then the two-way radios can be equipped with headsets. A high-quality two-way radio like the MURS J-V110 Two-Way Radio fits this need nicely because it has available headset options. It is also a very durable radio that will withstand the rigors of many events.

The good thing about a MURS Radio or intercom base station is that it allows you to extend range by using an external antenna. Both the handheld units and the base station units have what’s called a BNC connector that enables you to twist off the antenna that comes with the radio and then twist on a new antenna connected to a cable.

You will get noticeably better results and more range with your MURS radio with an external antenna. It is the single most important factor in increasing  transmitting and receiving range of a radio. You’ll need to make sure you choose an antenna that is specifically designed for the MURS frequencies and then choose the best location possible to install it.

The FCC limits antenna height for MURS radios to 20 feet above a structure (exclusive of the tower, mast or pole on which it is mounted), or 60 feet above ground (whichever is greater). The higher you place your antenna, the greater range you will get. If you mount an antenna on your vehicle and connect it to your mobile MURS two-way radio, the higher you place the antenna on your vehicle, the greater range you’ll get.

If you are using a handheld MURS radio and walking around with it, you can’t very well use an external antenna. You may be able to extend range by installing a better antenna than the one that came with the radio, but keep in mind that the antenna that came with the radio is “tuned” specifically for that radio. If you put on an antenna that isn’t properly tuned, you could lower range.

IntercomsOnline.com does not offer external antennas, find them by clicking on this link: external MURS antenna. You’ll find antennas you can mount on your car, building, or even inside antennas that will increase the range of your MURS Radio.

If you’re looking for the longest range wireless outdoor intercom, there is really only one type of system that will meet your needs. That is assuming by long range you mean more than 1000 feet.

The outside wireless intercom system we put together for our clients is based on the MURS callboxes we offer. These callboxes can communicate at ranges of up to two miles. They are not inexpensive products, but unfortunately an inexpensive option doesn’t exist where long range is needed.

These MURS outdoor callboxes communicate with our MURS Commercial Intercom or our MURS 4-Mile Range Intercom base stations, or available handheld two-way radios we offer. That gives you the ability to configure a system with stationary or mobile radios.

By combining these products you can put together the longest range wireless outdoor intercom system available.

If you want to be alerted when a vehicle is approaching your house or business, a driveway alarm can be used to monitor your driveway and send you a signal when it detects an approaching vehicle.

There are two different detection devices available. One detects motion and the other metal. The motion detector as it sounds will detect movement of vehicles, people, and large animals. If you live in an area where there are frequently deer around, you may get false signals caused by the deer.

You can get detectors in wireless and wired. Of course the wired system requires you to run a wire between the sensor and the monitor whereas the wireless detector doesn’t.

If you only want to detect vehicles, then you can get a detector with a metal detecting probe that is buried next to your driveway. With the probe, you won’t have false alerts cause by animals or people.

If you have a short driveway (less than 500 feet) the WireFree Wireless Alert System with 2-Way Voice Communication can be used. Not only will it tell you when it detects movement near the sensor, it will also let you carry on two-way communication with whoever is near the sensor. No metal detecting probe is available for this unit.

If you have a driveway as long as a couple of miles you can still use wireless driveway alarms. The MURS Alert has a range of up to four miles in perfect conditions, but realistically it should easily reach two miles under most conditions. It will sound a verbal “Alert Zone One” message when the sensor is triggered. This system has either a metal detecting probe or a motion sensing option. You cannot talk to the sensor like the system above, but you can use the monitor unit as an intercom system by adding additional monitors.

You can use these driveway alarms for more than just monitoring driveways. They can also be used for security applications as well. Both systems can be found at IntercomsOnline.com/

Many educational facilities are improving their school parking lot safety by placing a wireless emergency call box in the parking lot that communicates with wireless base station intercoms or hand held two-way radios. These call boxes are placed at strategic points around the campus parking lots and they enable a student to call for assistance.

A wireless base station intercom is placed in a security guard station, plus security guards are given handheld two-way radios so they can still receive calls while they are roaming the campus.

These callboxes add an extra level of security in the event a student does not have a cell phone or their cell phone battery is dead.