JESCO ELECTRIC CO
ELECTRICAL/RESIDENTIAL/COMMERCIAL/NEW CONSTRUCTION/REMODELING/GENERATORS/ SECURITY/CAMERAS/CABLE TV/PHONE/INTERCOM/AUTOMATION
While every intercom product line is different, most analogue intercom systems have much in common. Voice signals of about a volt or two are carried atop a direct current power rail of 12, 30 or 48 volts which uses a pair of conductors. Signal light indications between stations can be accomplished through the use of additional conductors or can be carried on the main voice pair via tone frequencies sent above or below the speech frequency range. Multiple channels of simultaneous conversations can be carried over additional conductors within a cable or by frequency- or time-division multiplexing in the analogue domain. Multiple channels can easily be carried by packet-switched digital intercom signals.
Portable intercoms are connected primarily using common shielded, twisted pair microphone cabling terminated with 3-pin XLR connectors. Building and vehicle intercoms are connected in a similar manner with shielded cabling often containing more than one twisted pair.
Digital intercoms use Category 5 cable and relay information back and forth in data packets using the Internet protocol architecture.
For installations where it is not
desirable or possible to run wires to support an intercom system, wireless
intercom systems are available. There are two major benefits of a wireless
intercom system over the traditional wired intercom. The first is that
installation is much easier since no wires have to be run between intercom
units. The second is that you can easily move the units at any time. With that
convenience and ease of installation comes a risk of interference from other
wireless and electrical devices. Nearby wireless devices such as cordless
telephones, wireless data networks, and remote audio speakers, as well as
structural features in your building, can all interfere. Electrical devices such
as motors, lighting fixtures and transformers can cause noise. There may be
concerns about privacy since conversations may be picked up on a scanner, baby
monitor, cordless phone, or a similar device on the same frequency. Encrypted
wireless intercoms can reduce or eliminate privacy risks, while placement,
installation, construction, grounding and shielding methods can reduce or
eliminate the detrimental effects of external interference. The United States
and Canada have several frequency ranges for wireless intercom systems and other
wireless products. They are 49 MHz, FM band (200KH – 270 kHz), 494–608 MHz, 900
MHz, 2.4 GHz, 5.8 GHz, and MURS (150 MHz).
When a visitor presses the button on the door intercom, the Doorbell Fon rings the phones in your home with a distinctive ring. Pick up the phone to converse with the door. If you are on the phone when a visitor arrives a call-waiting tone will sound to alert you.
Up to 2 intercom stations can be attached. Add the optional lock controller and an electric door strike and you can unlock the door from the phone by pressing the [*] key. Easy 2 wire connection to door intercoms. Works with answering machines and most PBX phone systems. Includes one door intercom station and power supply.