Tuesday, January 25, 2011

Intercom: Wired, Wireless and Telephone Intercom Systems

Opting for wireless intercom is more beneficial than purchasing the standard wired intercoms. With wireless intercoms, no wires are needed for installation which is great for places where setting up of wires is not possible. One can save money that would go when setting the wires of a wired intercom. Also, wireless intercom is a portable system which means the user can easily carry the units around or transfer it from one place to another.

However, interference problem with the intercom can still be encountered with other wireless intercoms and devices as well as with electrical units. Wireless devices like wireless data networks, remote audio speakers and cordless telephones can interfere with communication. Motors, transformers, and lighting fixtures are some of the electrical units that cause interference like emitting noise upon transmission. And in wireless intercom, conversations can be overheard or picked up with other wireless intercoms of similar frequency such as baby monitors, scanner, and cordless phones.

Though nowadays, wireless intercom comes with encryptions thus making the communication more secure and private. If the intercom was constructed properly, placed and installed in the right location, and has been grounded and shielded well, interference from outside sources is less likely to occur. The frequency ranges of wireless intercoms and products made available to the public by United States and in Canada are 49 MHz, FM band (200 kHz - 270 kHz), 494-608 MHz, 900 MHz, 2.4 GHz, 5.8 GHz and MURS (150 MHz).

But with power line communication units, despite its being a non wireless product it is sold and included in the wireless intercom category. Transmission of signals is through the existing house wiring or the wiring above the building. It is said to be wireless for the reason that similar to wireless products, wires are not required.

Telephone Intercom

With the technology of today, telephone units can be made into intercom. Not only can one use the unit to communicate but paging is also possible as long as it is done with similar units or models. To name some are TMC model ET4300, AT&T models 945 and 974, and Panasonic model KX-TS3282W(/B).

For telephones that have general phone line, adding a device that comes with intercom function can give identical functionality to the telephone unit. Installation can be done easily, radio interference is no more, and privacy issues that come with some of the wireless intercom is not a problem. The Add-A-Com Whole House Intercom for Standard Telephone System is an example of this telephone intercom.

When the intercom paging is activated, one hears a very distinctive ring coming from the telephones as soon as a phone is off the hook. As soon as the external phone is disconnected in this instance, the phones are turned into an intercom and only ended once the phones are hooked again which in turn reconnects the external phone. Although even in the middle of using the intercom, incoming external calls can be still noted for a ringing sound will be heard over the earpiece. The telephone intercom and wireless intercom are both alike in the way of communication ease and convenience.

Sunday, January 2, 2011

Wireless Intercoms: Wiring System of Intercoms

Wireless intercoms are wired differently from each another. From the analogue intercoms to portable intercoms and also to digital intercoms, conversations are sent and received in a way unlike from others. However with these wireless intercoms, communication is still done in a convenient way.

Wiring intercoms

Most of the analogue intercoms carry voice signals with 1 or 2 volts through conductors atop power rails with direct current of 12, 30 or 48 volts. The signal lights are through extra conductors or through tone frequencies of the main voice that are sent either on top or below the audio frequency band. For multiple conversations over many channels, the signal are carried through added conductors or though frequency/time-division multiplexing in analogue field. Also, multiple channels are transmitted over signals of packet-switched digital intercoms.

As for the portable intercoms, connections utilize shielded, twisted pair of microphone cables and terminated through 3-pin XLR connectors. Similar connections are employed by vehicle and building intercoms although shielded cabling consist many twisted pair instead of just one. And in digital intercoms, Category 5 cable is used and delivers and receives conversations in Internet-protocol-architecture data packets.

Broadcast Intercoms

Just like the popular wireless intercoms of today, there are two intercom systems that are popularly utilized by TV stations and broadcast vehicles like those used to cover sporting events and such in previous years. These two intercoms are the two-wire party line and four-wire matrix systems. During the early years, TV stations use old phones for communication system but this was improved to the off-the-shelf systems of today’s intercoms.


The system of two-wire line party was common during late 1970s to mid 1990s which use a 32 Volts of impedance generating power supply transmitted to outside drive stations or even belt packs. This two channel type has made operation of two channels using the standard microphone cable possible. Usually comes with a limited flexibility and capacity of being hardwired but are easily maintained and operated with a durable design. However, the user would converse with one person or group and cannot communicate with others until the system was reconfigured otherwise.

Reconfiguration was then done with two-wire routers or with source-assigned panels at the central location of the system. But since the circuit use voltage for communication and external station power there are pops occurring as the channels switched. Although this changing of system is not recommended while a production is in operation for the popping sound would likely sidetrack the other production crew.


The four-wire intercoms have become more widely known during the mid 90s as the technology designed smaller and sold at a cheaper price. This four-wire technology may be present for some time but since implementation needed a lot of money, it was not very popular. These intercoms were only utilized by large stations and TV networks for it needs large physical footprint within the television studio. However compared to wireless intercoms, the wireless systems have gained more distinction.

Monday, December 20, 2010

Wireless Intercom: Partner in Business

Installing a wireless intercom inside your business building is a prudent decision. With this system, the evacuation plan for emergency cases can be executed successfully. However, tenants must have knowledge of this plan, starting from the planning to the procedures and to the available emergency equipments. Together with the information learned and communicated through the wireless intercom, tenants can evacuate the area efficiently and safely.

In emergency preparation, inspect the property from top to bottom and note the possible dangerous area, safe areas, and particularly the exit doors. After the thorough inspection, install monitoring or detecting devices such as smoke detectors. Then carry out the installation of the very essential communication system. Example of this system is the wireless intercom system in which can be use to notify people responsible for evacuation in emergency cases and inform them of the proper reaction to take.

The usage of a wireless intercom depends on how the building proprietor uses it. If utilize as an alarm system, it can be termed as evacuation emergency system. With the system in place, the residents can be made aware of the manner of emergency, the corresponding procedures to execute, and thus be guided to the correct exit routes. This can also be used to do emergency drills as a run through for everybody’s benefits and as a way to check the devices if everything is all in working condition.

For people with business building or an office rented, be sure to look into the safety standards the Occupational Safety & Health Administration (OSHA) provides. The OSHA has also given a recommendation to install a “Workplace Announcement System” which requires owners to have PA speakers. Adding these speakers to your wireless intercom can allow you to play recorded messages or broadcast live messages.

This wireless intercom system is an inexpensive alternative to use in emergency situations without sacrificing the safety of the employees. One must also follow the safety standards when performing the emergency evacuation particularly in business’ offices. Prior to purchasing safety equipments, go over your safety regulations and select the ideal device that meet with the terms. A wireless intercom is an efficient tool in aiding the evacuation of the tenants effectively to a safe place.

Wednesday, December 8, 2010

Emergency Call Box: Broadcast with MURS Wireless Public Address

The emergency call box, MURS Wireless PA (Public Address), conveys voice messages straight from your 2-way mobile radio or base station intercom to the PA speaker that is installed no more than 2 miles in distance. Both the PA receiver and PA speaker can easily be installed and are made for large properties or campuses so everyone can hear the message sent. If hardwired set up is not possible or just too costly and temporary, this emergency call box is ideal for you.

MURS Wireless PA with other MURS Products

MURS Wireless PA is compatible with any of the MURS products that make use of the same frequencies which need no license to operate. When worked together with MURS Commercial Intercom or MURS J-V110 Two-Way Radio, it is possible to program MURS Wireless PA so that only those with the proper code can access the device. With this programming, you can be sure that those who are allowed can only use the system. In addition, you can have a normal conversation using the MURS Wireless PA and your intercom or radio through a dedicated communication channel without it broadcasted.

Zone Paging

You can have as many MURS Wireless PA receivers installed throughout the property so you can do paging or zone paging. Either have a code different for each receiver or use the “All Call” code so you can page all zones at the same time. Although with this feature you require the elective DTMF tone decoder set up in your MURS Wireless PA.

Having two loudspeakers installed in one MURS Wireless PA receiver can give you a wider area for coverage. One speaker can reach up to 100 feet away and comes with a cable of 25 feet. This cable can be further extended with the standard RCA phono cables and couplers.

Play Recorded Messages and Weather Broadcasts

Using your two-way radios in the same vicinity as your emergency call box speaker can make your system non-functional. To avoid this, you can have the receiver record the messages received and program it to play back messages over the emergency call box’s speaker once the person using the two-way radio has stopped talking and released the talk button. You only have 20 seconds to record your message.

It is also possible to broadcast emergency weather reports over the speaker to notify everybody. Simply program your MURS Wireless PA to tune in and receive the local NOAA weather from National Weather Service. Also, set your device to have the same frequency as your local weather radio.

MURS Wireless PA

The MURS Wireless PA receiver requires 110VAC power. It also comes equipped with an emergency backup battery that can temporarily power the radio if primary power is interrupted. The rechargeable battery backup is not intended to operate the radio for an extended period of time. A heavy duty external +12 VDC battery can also be used to power the receiver and the receiver can be configured for powered operation to maximize battery life. A solar panel kit can be used to power the MURS Wireless PA receiver without the need for a power supply in locations where AC power is not available.

MURS Wireless PA power on 110V and comes with a backup battery that would power the radio in case of emergencies such as power outage but only for a short time. You can also use the long-lasting external +12 VDC battery to power the emergency call box’s receiver and have it configure to maximize the battery life while in operation. In the event that AC power is not accessible, you can use the solar panel kit to power the device.

To get a wider coverage, you can install the optional external antenna. Have this magnet-mount antenna set up in a place of higher elevation. This antenna comes with a 25 feet cable for maximum coverage.

Usually the emergency call box receiver is not designed to be waterproof. However, there is a fibreglass reinforced polyester enclosure that is weatherproof for the receiver and antenna. This enclosure is for out-of-doors, short term use only.

For heavy traffic places that use MURS radios, the device comes with “2-Tone Decode” capacity. This feature makes it possible for the unit to accept pages coming from “2-Tone Encode” radios. Examples of radios having this feature are MURS J-V110 Two-Way Radio and MURS Commercial Intercom.

Installation and Programming

Once installed, operating the MURS Wireless Public Address radio receiver requires no human contact. The MURS Wireless PA reduces installation costs that would otherwise be incurred by using a wireless PA system.

The MURS Wireless PA receiver does not need any human supervision after it is installed. Having this unit installed is less costly than having the wireless PA system. Once installed, you can use the MURS Channel 1 which is already programmed to the unit with the Interference Eliminator code of 01 just like other MURS Radios. Avoid programming this emergency call box except for enabling other features, although this device is programmable.

Sunday, November 28, 2010

MURS Radios: Usage of WireFree Doorbell and Intercom

MURS Radios’ WireFree Wireless Doorbell and Intercom will give a two-tone sound when the Call button is pressed by a visitor at the door which will then give similar tone throughout the house via WireFree Portable intercoms two seconds after. A house member would then reply to the guest through WireFree Portable by pushing the button Talk. The visitor has 40 seconds to talk without touching the button again but the house member has to press the Talk button every time he/she responds. The microphone of the MURS Radios will only be enabled for about 40 seconds before turning off thus cutting all sounds so you have to press the button again.

The difference between WireFree Outdoor Intercom and Wireless Doorbell is that you can’t make a call with the latter. In order to work, the person outside must press the Call button before someone inside the house replies by pushing the Talk button on the indoor intercom. Another difference between the two is that WireFree Outdoor Intercom does not come with hands-free, speakerphone type conversation unlike the Wireless Doorbell.

You can install a maximum of 11 MURS Radios WireFree Portable intercoms inside and once someone presses the Call button of the outdoor intercom, every indoor intercom will receive the doorbell tone as well. Either you can have a secure channel with the unit for private conversations or set it up in a Conference mode so everybody can hear the response.

Additional Uses

Having this unit can be very convenient when caring for an elderly patient or disabled person. However this will only work if that person can press the button even once. With this intercom, the caregiver can be summoned upon hearing the doorbell chime. However, the caregiver can’t contact the person under his/her care through the unit but this will not be a problem for the caregiver is generally a fit person that he/she can simply walk to his/her charge anytime.

The white-coloured outdoor intercom is usually mounted at the wall but you can have it mounted at the table top with some minor modifications. Simply buy self-adhesive vinyl bumpers that are normally used to keep cabinet doors quiet when closing, at your neighbouring hardware. Then you can stick five of these bumpers on the outdoor intercom’s bottom and place it anywhere you like without the problem of having it slide out of place.

Just remember that these MURS Radios units are not compatible with the units that are bought on January 2010 and backwards.

Monday, November 8, 2010

MURS Radios: MURS Callbox

MURS Radios, which sounds like ‘furs’, is a set of frequencies for communication use in personal or business reasons that is newly added by the FCC. MURS is not that popular and many have not heard about it so there won’t be a heavy traffic in most areas on it. The MURS have only five available channels together with 38 quiet codes that enable users to hear only the conversations that are set on the same channel and code as them to ensure privacy. Every intercoms and radios available with MURS Radios have no compatibility problems with each other and you can even combine them or mix and match them to your preference.

Most intercoms need to be set up with wires that may run through a concrete or asphalt areas or over some extended distances that will cost you thousands of dollars, and the added nuisance of acquiring permits before the digging starts. Problems may arise with this kind of set up such as wiring unintentionally cut or the wiring goes bad resulting to doing the set up once again. To avoid all these troubles, get the MURS Callbox instead for a faster and cheaper installation. The MURS XT Callbox is compatible with any MURS Radios and gives a range of at most 1 mile in distance and more if you add an external antenna, as well as communication via 2-way voice from the call box’s location to the units of MURS intercom.

MURS Callbox, an outdoor intercom is especially made for heavy duty use such as in construction sites, motels or hotels, resorts, golf courses, amusement parks, campgrounds, parking lot (airports, business buildings, etc.), gated or locked entrances, warehouses, hospitals, college campuses, farm or ranches, receiving docks, and delivery doors to name a few for easy and convenient two way communication which is needed also for security reasons. This callbox is wireless therefore no wiring, remodeling, trenching, or the costly monthly payment that comes with phone lines installation is needed. The MURS Callbox of MURS Radios can be operated using 6 D-cell batteries (Ni-Cad or alkaline rechargeable) for simple and uncomplicated installation or you can get the elective external power supply.

Tuesday, October 26, 2010

MURS Radios: Why You Need One

MURS Radios are used to facilitate and make communication easier in your house and this is the foremost and fundamental advantage you can get with it. Calling a room specifically or one of the rooms and have a private communication is possible depending only on the individual’s preference and what they feel is right for them. You can also do long range communications with devices set apart in a distance. In addition, the MURS radios can be added with an external antenna to increase and boost the communication over a distance.

MURS radios can also be used for monitoring process. With this intercom, you can check your children’s activity and be able to keep in touch with them. When your kids are playing or just inside their rooms, you can monitor them with this gadget thus making it convenient for the parents. Not only can you monitor your kids with it, you can also take care of your parents through the use of the Monitor feature on a Built-In Home Intercom System installed inside your parent’s room to check once in a while it they need assistance or they simply can call you.

The intercom can make the household feel secure when they are inside their own homes. When you have a visitor, you can know his/her identity while they are still at your door so you need not get up or leave your work to open the door when a visitor knocks. The wireless intercom have a built in music feature that would distribute music throughout the house conveniently and this is very beneficial in case you want to put your property on the market for it adds value to the property.

Everyone wants to have privacy in their lives and with MURS radios this privacy that you crave is given to you. You can monitor everything happening in your property, those who enters or leaves his surrounding’s precincts is possible with this intercom. Having this installed in the house is very convenient and handy for those parents who have children in the adolescent age group living inside the house.

The intercom has a remote control that uses basic functions. This can be very handy for you can use the remote control to unlock the door and you do not have to leave your seat when doing it. There are also some intercoms that you can synchronize with your iPod, mp3 or palm tops to work with. Having MURS radios is simply convenient for you and your household’s lives.