Two Way radios | 2 Way Radio for Professional & Amateur

Race Communications | Two Way Radio For Racing

2010-08-06T10:07:00.000-07:00

Two Way Radio For Racing (Car & Motor Cycle) with Motorola system
example System:
2 Unit Motorola CP200 4CH UHF
1 Car Radio Holder
Push-To-Talk Switches
Batteries
Roof Mount Antenna
Antenna Adapter
Stock Car Helmet Adaptor
Stock Car Flex Boom Helmet
open face stock car metal helmet kit
Scanner Headsets
2-Way Headsets and Cables
optional
Repeater system
Compact 25-40 watt Motorola race repeater system.
Mag Mount Antenna
Duplexer (for single antenna operation)

Vertex two way radio

2010-03-03T00:24:00.000-08:00

Compact two way radio
The vertex VX-146 is one of the latest models in the Vertex Standard range
of high quality, cost effective handheld transceivers for the European PMR446 service. The VX-146 can be very simply cloned in the field using the optional CT-27 clone cable, ensuring easy and rapid deployment if required.
vertex VX-146 Features
* It is PC programmable with the ability to configure all features and functions for downloading into the radio
* PC configurations can be saved on the PC for security
Additional Features
* Ideal for harsh environements
* Alpha-Tagged Channels with LCD Display
* 16 Channel Capacity
* CTCSS/DCS Selective Tones
* Small Size and Light Weight
* ARTS - Automatic Range Transponder System

Frequencies:
UHF
446.00625
446.05625
446.01875
446.06875
446.03125
446.08125
446.04375
446.09375

Vertex two way radio | vx920, ruggedness

2010-03-03T00:14:00.001-08:00

Two way radio, Reliability, ruggedness, and inter-operability like never before. The VX-920E series of Vertex Standard two way radio is ready to respond when you are, with a wide array of signaling capability, along with big audio, operator and system security measures, and PC programmable for quick deployment.
Frequency Range:
134-174 MHz VHF
400-470 MHz UHF
Vertex two way radio Features
* 512 Channels & 32 Groups
* Lightweight & Large LCD
* 5W Power Output (selectable to 2.5, 1 & 0.25 watt power levels)
* Rugged Construction - MIL-STD 810 C/D/E
* CTCSS/DCS Encode & Decode
* 12.5/25 Khz Bandwidth Programmable By Channel
* 5-Tone as Standard
* 12 Character Dot Matrix Display
* PC Programmable
* RadioTo Radio Cloning
* BCLO, BTLO, and TOT Functions
* 2 Programmable Soft Keys
* 1 Multi-Position Programmable Toggle Switch
* Voice Inversion Encryption Available
* ARTS (Auto-Range Transponder System

Vertex two way radios | Vertex vx 820

2010-03-03T00:07:00.000-08:00

The Vertex vx 820 E series of Vertex Standard two way radios answers the call with a wide array of signaling capability, along with big audio, operator and system security measures, and PC programmability for quick deployment.
Frequency Range:
134-174 MHz VHF
400-470 MHz UHF
Main Features
* 200 Channel Capacity
* Lightweight & Compact Size
* 5W Power Output (selectable to 2.5, 1 & 0.25 watt power levels)
* Rugged Construction - MIL-STD 810 C/D/E
* CTCSS/DCS Encode & Decode
* 12.5/25 Khz Bandwidth Programmable By Channel
* 5-Tone as Standard
* Advanced 8 Character Invertible Alphanumeric Display
* PC Programmable
* RadioTo Radio Cloning
* BCLO, BTLO, and TOT Functions
* 2 Programmable Soft Keys
* 1 Multi-Position Programmable Toggle Switch
* Voice Inversion Encryption Available

Durable Two way radio ( motorola)

2008-06-19T11:12:00.000-07:00

Digital Two radios & Durable (military) by Motorola:
Motorola XTS 5000 Digital Portable Radio
This two way radio is the toughest and most advanced interoperable digital portable radio Motorola makes. It assures high-quality communication through a robust design that stands up to the most demanding environments. Enhanced spectrum utilization and seamless integration deliver a clear, crisp signal, even in congested urban areas or dispersed rural regions. The radio is IP-enabled, offering a full array of sophisticated features and progressive technology.
Advanced emergency capability
features:
Keeps emergency calls viable, even when unit is switched off and Allows emergency communication without depressing the PTT button
Enhanced audio: Delivers a clear signal via noise reduction software.
Interoperable voice signaling: Complies with APCO P25 standards.
Audible channel announcement: Uses a prerecorded voice file to describe channels or talk groups as the user navigates.
POP25 access functionality: Allows subscriber to access and update radio configuration over the air.
Durable design: Meets military specs 810 C, 810 D, 810 E and 810 F, for resistance to shocks and extreme weather.
Hardware and software encryption: Prevents scanners, unwanted listeners and other interference.
Built-in FLASHport support: Allows users customize with new software.
Customer programming software : Supports USB and RS-232 functionalities.
specs this Two way radio:
Frequency band VHF, UHF, 700 MHz, 800 MHz
Battery life (based on a 5/5/90 duty cycle) 8 hours (all battery types) Standard battery chemistry type Nickel Cadmium .
Frequency range 700/800 MHz: 764-870MHz; VHF: 136-174 MHz; UHF Range 1: 380-470 MHz; UHF Range 2: 450-520 MHz

A two way radio

2008-04-23T12:18:00.000-07:00

Two way radio for best telecommunication from: Vertex audiovox icom midland maxon motorola Uniden yaesu cobra bellsouth etc. Two way radio vhf UHF Low band, mobile Portable gmrs frs Accessory battery. walkie talkie handie talkie 2 Way radio 10 20 mile short middle long wide range. repeaters utility mobile transceivers, marine ham radio equipment fixed-mount radio handheld GPS standard Defense military/ emergency situations land mobile portable radio amateur. Professional Digital system 2 way Radio. Finds the Best two way radios

Hand-held portable two-way radios are often called walkie-talkies or handie-talkies.

Two-way radio A voice network that provides an always-on connection

Motorola Portable Radio : CP200 two way radio

2008-03-16T22:36:00.001-07:00

Portable Two way radio (handietalkie/walkietalkie) to provide the range that’s best for your business, Motorola CP200 Portable Two Way Radio is available in both 4W UHF and 5W VHF models. Powerful 500 mW audio output penetrates noisy environments, providing clear, crisp audio at any volume. A lightweight, ergonomic design makes these radios comfortable to carry and operate, even while wearing gloves. A range of battery choices along with rapid recharging capabilities help ensure your radio is ready when you are. Programmable option buttons make it easy to customize your radio with your choice of features.

Motorola CP200 Portable Two Way Radio offers the increased communication flexibility of push-to-talk radio ID and selective call.Frequency: VHF (136–162, 146–174MHz),and UHF (403–440, 438–470, 465–495MHz), Power : 2W & 5W, Channels: 4 & 16.

Motorola Portable Radio : CP150 two way radio

2008-03-16T22:28:00.000-07:00

Portable two way radios with quality features and competitive price, Motorola CP150, this To provide the range that’s best for your business, the CP150™ radio is available in 2W UHF and VHF models. A lightweight, ergonomic design makes these radios comfortable to carry and operate, even while wearing gloves. A range of battery choices along with rapid recharging capabilities help ensure your radio is ready when you are. Programmable option buttons make it easy to customize your radio with your choice of features. Battery Life (based on 5/5/90 duty cycle) - 9 hours, Channels - 4 & 16, Frequency - VHF (146–174MHz), UHF (438–470MHz).

Motorola Portable Radio : CP125 two way radio

2008-03-16T22:18:00.000-07:00

Two way radio for businnes with A Durable, Affordable and Effective Communications Solution, This Motorola CP125 With adjustable power levels and programmable function controls, the Radius CP125 provides users with the flexibility and features they need to succeed. Fully equipped with Voice-Activated Transmission (VOX) capabilities*, the Radius CP125 supports hands-free communications via an optional headset—so users can stay connected while focusing on the job at hand.High power: 5 Watt (VHF)/4 Watt (UHF). Adjustable power levels help save battery life. With Multi-channel capable: four channels allow you to communicate with separate workgroups. Durable, lightweight design for optimal portability, ideal for employees on the move. Long-lasting battery life: up to 11 hours of battery life, more than enough for a long work shift.

Recommended for : Education, Retail, Property Management, Hospitality and etc.

Motorola Portable Radio : CP110

2008-03-16T22:07:00.000-07:00

Portable two way radio Affordable and easy to use, this Motorola CP110 portable two-way radio delivers just what you need to drive your business success: pace-setting performance and durability. It starts with exceptional audio quality enabling essential communication in loud environments. 2000 mW of audio output and other new design enhancements help the CP110 radios deliver audio that is 30% louder than previous Motorola CP100 radio models. And it keeps on going, with rugged construction to stand up to harsh job-site conditions. The CP110 features a durable metal die-cast chassis. It meets Military 810 C, D, E, F standards and IP54/55 specifications for shock, rain, humidity, salt fog, vibration, sand/dust, temperature shock plus high and low temperature.

Coverage : UHF: Up to 250,000 sq. feet, 20 floors. VHF: Up to 220,000 sq. feet, 13 floors. Coverage will vary based on terrain, conditions and the radio model used.

Motorola Portable Radio : CLS

2008-03-16T21:52:00.000-07:00

Two Way radio easy-to-use, affordable wireless solution, Motorola CLS Series portable business two-way radios.Designed with business productivity in mind, Motorola CLS Series radios and headsets provide a communication solution that is not only smart, simple and reliable but also able to withstand the daily rigors of the workplace. with Long lasting battery life Rechargeable Lithium Ion battery provides up to 12 hours of battery life for the Motorola CLS1110, more than enough for a standard work shift.

Operating on 56 business exclusive frequencies and featuring 121 codes, the Motorola CLS Series business radios will help ensure a clear signal is readily available (FCC license required).

Motorola CLS1410 This 4–channel, 1–Watt solution includes advanced voice activation for hands-free operation (with optional audio accessories), with VibraCall alerts the user with vibration instead of sound.

This Two way radios recommended for: Cashiers, Customer Service, Managers, Salespeople, Supervisors, Floor Clerks, Stock Clerks, Office Clerks, Buyers, Receiving Department, Security and etc.

Motorola Portable Radio : Mag One

2008-03-16T21:39:00.000-07:00

Mag One Two Way Radio by Motorola BPR 40 Portable Two Way Radio ( Channels - 8 Power - 1W/4W (UHF), 1W/5W (VHF)) is a radio portfolio at an incredible value (cheap) and price that is perfect for your business. The Mag One by Motorola BPR 40 Portable Two Way Radio offers affordable communications with a complete assortment of accessories to customize your radio. So when you select the Mag One by Motorola BPR 40 Portable Two Way Radio, you will experience a reliable, easy to use two-way radio at a great value. Motorola is excited to offer an affordable, high-performance communication tool that offers enhanced value and a reliable solution for you with great quality.

Motorola Portable Radio : CP100

2008-03-16T21:29:00.000-07:00

Motorola CP100 two-way radio is the perfect choice for businesses seeking clear, reliable performance at a very economical price. Its rugged, ergonomic design makes the CP100 durable enough to withstand hard conditions and easy to hold and carry. This two way radios/ Handy talkie or Walkie talkie: Motorola CP100 is available is available in both VHF and UHF bands.

Motorola P100 Single Channel Radio: Solid Performance at an Affordable Price. The single channel Motorola CP100 portable business two-way radio is the perfect choice for businesses seeking clear, reliable performance at a very economical price.
Its rugged, ergonomic design makes the CP100 durable enough to withstand harsh conditions and easy to hold and carry, even while wearing gloves. An extended life NiMH battery helps maximize talk time, and backup AA battery capacity gives users valuable power source flexibility. The radio’s built-in scrambling feature and 121 private lines provide plenty of options to ensure interference-free communication.
Easy to use and cost-efficient, the CP100 single channel radio delivers the capabilities you need to maximize effectiveness and maintain competitive advantage.

Motorola Two Radios

2008-03-16T21:07:00.000-07:00

Buy New Motorola Two Radio for Businnes, simple and Efficiency, productivity and safety are vital to your organization. With a wide variety of models and features, Motorola's two-way portable radios are an ideal solution for your communication needs.

Motorola Two Radio for businnes : for Providing smart, simple and reliable communications for work teams: Motorola Portable Radios/ Handytalkie or Walkie talkie:

BPR40, CLS1110, CLS1410,CP100, CP125, CP150,CP200, DTR410,DTR550, PR400, AXV5100, AXU4100, VL50, XU1100, XU2100, XU2600, XV1100T, XV2100, XV2600.

Two way radio wide range :

2008-01-19T08:54:00.000-08:00

Two way radio by Yaesu :

Yaesu's newest 144/430 MHz 5-Watt FM Hand-held was introduced at Dayton 2004. The FT-60R Two way radio, includes wide receiver coverage, outstanding audio quality, the most CTCSS/DCS flexibility in the industry, and a new Emergency Automatic Identification (EAI) feature for search-and-rescue work.

Yaesu 2 Wayradio model FT-60R A2 PKG-1 FNB-83 ANT NC-88B. this Two way radio: FT-60R 5W Dual Band Handheld w/FNB-83 7.2V1400mAh, Antenna, NC-88B.Two way radio model FT-60R A2 PKG-2 FNB-83 ANT NC-88C FT-60R 5W Dual this Two way radio: Band Handheld w/FNB-83 7.2V1400mAh, Antenna, NC-88C

Personal Two way radio

2007-09-14T12:19:00.000-07:00

Walkie talkie as personal Two way radio has become popular also because Family Radio Service (FRS) and similar unlicensed services (such as in Australia's UHF CB and Europe's PMR446) in other countries. While FRS walkie-talkies are also sometimes used as toys because mass-production makes them low cost, they have proper superheterodyne receivers and are a useful communication tool for both business and personal use. The boom in unlicensed transceivers has however been a source of frustration to users of licensed services that are sometimes interfered with (for example, FRS and GMRS overlap in the United States, resulting in substantial pirate use of the GMRS frequencies and requiring Canada to reallocate frequencies for unlicensed use due to heavy interference from US GMRS users, while the European PMR446 channels fall in the middle of a the US UHF amateur allocation and the US FRS channels interfere with public safety communications in the United Kingdom). Designs for personal walkie-talkies are in any case tightly regulated, generally requiring non-removable antennas (with a few exceptions such as CB radio and the United States MURS allocation) and forbidding modified radios.Most personal walkie-talkies sold are designed to operate in UHF allocations, and are designed to be very compact, with buttons for changing channels and other settings on the face of the radio and a short, fixed antenna. Most such units are made of heavy, often brightly colored plastic, though some more expensive units have ruggedized metal or plastic cases. Commercial-grade radios are often designed to be used on allocations such as GMRS or MURS (the latter of which has had very little readily available purpose-built equipment).

In addition, CB walkie-talkies are available, but less popular due to the propagation characteristics of the 27MHz band and the general bulkiness of the gear involved.While not frequency-agile in the same manner as amateur radio HTs, personal walkie-talkies are generally designed to give easy access to all available channels (and, if supplied, squelch codes) within the device's specified allocation.Personal two-way radios are also sometimes combined with other electronic devices; Garmin's Rino series combine a GPS receiver in the same package as an FRS/GMRS walkie-talkie (allowing Rino users to transmit digital location data to each other), while DingoTel allows the interfacing of FRS gear to a VoIP connection. Some personal radios also include receivers for AM and FM broadcast radio and, where applicable, NOAA Weather Radio and similar systems broadcasting on the same frequencies.
While jobsite and government radios are often rated in power output, consumer radios are frequently and controversially rated in mile or kilometer ratings; because of the line of sight propagation of UHF signals, however, experienced users consider such ratings to be wildly exaggerated, and some manufacturers have begun printing range ratings on the package based on terrain as opposed to simple power output. Find two way radios 30 miles, digital Trunked Mobile, BellSouth 2 way radio support multi band two way radio.

Two Way Radio Walkie Talkie

2007-09-14T12:11:00.000-07:00

Walkie talkie ( Or handie Talkie..more formally known as a handheld transceiver) is a hand-held portable, two-way radio transceiver. Major characteristics include a half duplex channel (only one radio transmits at a time, though any number can listen) and a push-to-talk switch that starts transmission. Typical walkie-talkies resemble a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top. Where a phone's earpiece is only loud enough to be heard by the user, a walkie-talkie's built-in speaker can be heard by the user and those in his immediate vicinity. Hand-held transceivers may be used to communicate between each other, or to vehicle-mounted or base stations.Since even a powerful commercial walkie-talkie is limited to a few watts of power output and a small antenna (the physical size of the package limits both battery capacity and antenna size), hand-held communication range is typically quite short, not exceeding the line-of-sight distance to the horizon in open areas, and very much less in built-up areas, within buildings, or underground.

Many radio services permit the use of a repeater which is located at some high point within the desired coverage area. The repeater listens on one frequency and retransmits on another, so that reliable hand-held to hand-held unit range can be extended to a few score miles (kilometers) or further, using repeaters linked together. Walkie talkies for public safety, commercial and industrial uses may be part of trunked radio systems, which dynamically allocate radio channels for more efficient use of limited radio spectrum. And some cellular telephone networks offer a push-to-talk handset that allows walkie talkie like operation over the ceullular network, without dialling a call each time.Walkie talkies are widely used in any setting where portable radio communications are necessary, including business, public safety, outdoor recreation, and the like, and devices are available at numerous price points from inexpensive analog units sold as toys up to ruggedized ( waterproof or intrinsically safe) analog and digital units for use on boats or in heavy industry. Most countries, at the very least, will allow the sale of walkie-talkies for business, marine communications, and some personal uses such as CB radio, as well as amateur radio designs. Walkie-talkies, thanks to increasing use of miniaturized electronics, can be made very small, with some personal two-way UHF radio models being smaller.In addition, as costs come down, it is possible to add advanced squelch capabilities such as CTCSS (analog squelch) and DCS (digital squelch) (often marketed as "privacy codes) to inexpensive radios, as well as voice scrambling and trunking capabilities. Some units (especially amateur HTs, but also some commercial designs) also include DTMF keypads for remote operation of various devices such as repeaters. Some models also include VOX capability for hands-free operation, as well as the ability to attach external microphones and speakers.

Two way radio and Walkie talkie like from Cobra Kenwood Motorola and etc,

Two Way Radio Mobile

2007-09-14T11:47:00.000-07:00

Two Way radio Mobile for professional or Commercial mobile radios are often purchased from an equipment supplier or dealer whose staff will install the equipment into the user's vehicles. Large fleet users may buy radios directly from an equipment manufacturer and may even employ their own technical staff for installation and maintenance.A modern mobile radio consists of a radio transceiver, housed in a single box, and a microphone with a push-to-talk button. Each installation would also have a vehicle-mounted antenna connected to the transceiver by a coaxial cable. Some models may have an external, separate speaker which can be positioned and oriented facing the driver to overcome ambient road noise present when driving. Some Two way mobile radios use noise-canceling microphones or headsets. At speeds over 100 MPH, the ambient road and wind noise can make radio communications difficult to understand. For example, some Police Highway Patrol mobile radios have noise-canceling microphones which reduce road and siren noise heard by the dispatcher. Most fire engines and radios in heavy equipment use noise-canceling headsets. These protect the occupant's hearing and reduce background noise in the transmitted audio. Noise-canceling microphones require the operator speak directly into the front of the microphone. Hole arrays in the back of the microphone pick up ambient noise. This is applied, out-of-phase, to the back of the microphone, effectively reducing or canceling any sound which is present both in front and back of the microphone. Ideally, only the voice present on the front side of the microphone goes out on the air.Many radios are equipped with transmitter time-out timers which limit the length of a transmission. A bane of push-to-talk systems is the stuck microphone: a radio locked on transmit which disrupts communications on a two way radio system. One example of this problem occurred in a car with a concealed two way radio installation where the microphone and coiled cord were hidden inside the glove box. An operator tossed the mike into the glove box and shut it, causing the push-to-talk button to be depressed and locking the transmitter on.

Radios with time-out timers transmit for the preset amount of time, usually 30 or 60 seconds, after which the transmitter automatically turns off and a loud tone comes out of the radio speaker. The volume level of the tone on some radios is loud and cannot be adjusted. As soon as the push-to-talk button is released, the tone stops and the timer resets. Two way mobile radio must have an associated antenna. The most common antennas are stainless steel wire or rod whips which protrude vertically from the vehicle. Get the Mobile Two way radios like from Kenwood or motorola, yaesu vertec, Icom BellSouth, uniden and etc.

Mobile Two Way Radio

2007-09-14T11:36:00.000-07:00

Two way Mobile radio or mobiles refer to wireless communications systems and devices which are based on radio frequencies, and where the path of communications is movable on either end. A sales person or radio repair shop would understand the word mobile to mean vehicle-mounted: a transmitter-receiver (transceiver) used for radio communications from a vehicle. Mobile radios are mounted to a motor vehicle usually with the microphone and control panel in reach of the driver.Early Two way mobile radios used amplitude modulation (AM) to convey intelligence through the communications channel. In time, problems with sources of electrical noise showed that frequency modulation (FM) was superior for its ability to cope with vehicle ignition and power line noise.

The frequency range used by most early radio systems, 25 to 50 MHz (vhf "low band") is particularly susceptible to the problem of electrical noise. This plus the need for more channels led to the eventual expansion of two-way radio communications into the VHF "high band" (150 to 174 MHz) and UHF (450 to 470 MHz). The UHF band has since been expanded again. One of the major challenges in early mobile radio technology was that of converting the six or twelve volt power supply of the vehicle to the high voltage needed to operate the vacuum tubes in the radio. Early tube-type radios used dynamotors - essentially a six or twelve volt motor that turned a generator to provide the high voltages required by the vacuum tubes. Some early mobile radios were the size of a suitcase or had separate boxes for the transmitter and receiver. As time went on, power supply technology evolved to use first electromechanical vibrators, then solid-state power supplies to provide high voltage for the vacuum tubes. These circuits, called "inverters", changed the 6V or 12V direct current (DC) to alternating current (AC) which could be passed through a transformer to make high voltage.

Now Two way radio (mobile) is with Custom design for a particular customer is a thing of the past. Modern mobile radio equipment is "feature rich". A mobile radio may have 100 or more channels, be microprocessor controlled and have built-in options such as unit ID. A computer and software is typically required to program the features and channels of the mobile radio. Menus of options may be several levels deep and offer a complicated array of possibilities. Some mobile radios have alphanumeric displays that translate channel numbers (F1, F2) to a phrase more meaningful to the user,and are now designed with a myriad of features to preclude the need for custom design. Finds Best Mobile two way Radio

Two Way Radio Base Station

2007-09-14T11:21:00.000-07:00

Two-way radio for Professional user. In professional two-way radio systems, a base station is used to maintain contact with a dispatch fleet of hand-held Portable or mobile radios, and/or to activate one-way paging receivers. The base station is one end of a communications link. The other end is a movable vehicle-mounted radio or walkie-talkie. Examples of base station uses in two-way radio, and somePolice dept, Fire dept and include the dispatch of tow trucks and taxicabs, or Company who need low cost communication.
Professional base station radios are often one channel. In lightly-used base stations, a multi-channel unit may be employed. In heavily-used systems, the capability for additional channels, where needed, is accomplished by installing an additional base station for each channel. Each base station appears as a single channel on the dispatch center control console. In a properly designed dispatch center with several staff members, this allows each dispatcher to communicate simultaneously, independently of one another, on a different channel as necessary. For example, a taxi cab or Truck company dispatch center may have one base station on a high-rise building in LA City and another on a different channel in Providence. Each taxi dispatcher could communicate with taxis in either Boston or Providence by selecting the respective base station on his or her console.
In dispatching centers it is common for eight or more radio base stations to be connected to a single dispatching console. Dispatching personnel can tell which channel a message is being received on by a combination of local protocol, unit identifiers, volume settings, and busy indicator lights. A typical console has two speakers identified as select and unselect. Audio from a primary selected channel is routed to the select speaker and to a headset. Each channel has a busy light which flashes when someone talks on the associated channel.
Base stations can be local controlled or remote controlled. Local controlled base stations are operated by front panel controls on the base station cabinet. Remote control base stations can be operated over tone- or DC-remote circuits. The dispatch point console and remote base station are connected by leased private line telephone circuits, (sometimes called RTO circuits), a DS-1, or radio links. The consoles multiplex transmit commands onto remote control circuits. Some system configurations require duplex, or four wire, audio paths from the base station to the console. Others require only a two-wire or half duplex link.

Profesional Two Way radio.

Amateur radio (ham)

2007-09-14T11:09:00.000-07:00

In many countries, amateur licensing is a routine civil administrative matter. Amateurs are required to pass an examination to demonstrate technical knowledge, operating competence and awareness of legal and regulatory requirements in order to avoid interference with other amateurs and other radio services. There are often a series of exams available, each progressively more challenging and granting more privileges in terms of frequency availability, power output, permitted experimentation, and in some countries, distinctive callsigns. Some countries such as Great Britain and Australia have begun requiring a practical training course in addition to the written exams in order to obtain a beginner's license. These beginner's licenses are referred to as Foundation Licenses.
Amateur radio licensing in US serves as an example of the way some countries award different levels of amateur radio licenses based on technical knowledge. Licensees previously needed to demonstrate proficiency in Morse Code to obtain or upgrade a license. These requirements were phased out by the Federal Communications Commission, first from the entry-level Technician license in 1991, and eventually from all license classes on February 23, 2007. This conforms with international law, which no longer mandates Morse code testing, as well as views by the FCC that Morse code should be treated like other communications techniques, and that written testing is sufficient to prove that an applicant is qualified to obtain an amateur radio license. Some portions of the ham bands remain reserved for Morse code use only and the mode remains popular.In all countries, amateur radio operators are required to pass a licensing exam displaying knowledge and understanding of key concepts. In return, hams are granted operating privileges in larger segments of the radio frequency spectrum using a wide variety of communication techniques with higher power levels permitted. This practice is in contrast to other unlicensed personal radio services such as CB radio, Multi-Use Radio Service, or Family Radio Service / PMR446 that require type-approved equipment restricted in frequency range and power.
An amateur radio license is a legal document or permit giving official permission to the license holder to operate an amateur radio station. The license typically permits the bearer to transmit a signal on designated radio frequencies in order to conduct two-way communications with other licensed stations. In some countries, an amateur radio license is necessary in order to purchase or possess amateur radio equipment. Amateur radio licenses are issued by governmental authorities, typically the ministry or office of telecommunications of a national government. An amateur radio license is only valid in the country in which it is issued, or in another country that has a reciprocal licensing agreement with the issuing country.
Both the requirements for and privileges granted to a licensee vary from country to country, but generally follow the international regulations and standards established by the International Telecommunications Union and World Radio Conferences. Most governments issue several different classes of license, usually structured to grant additional privileges to those who demonstrate additional knowledge and proficiency.
An individual granted an amateur radio license is referred to as an amateur radio operator. In most countries, an individual will be assigned a call sign with their license. In some countries, a separate "station license" is required for any station used by an amateur radio operator. Amateur radio licenses may also be granted to organizations or clubs. Some countries only allow ham radio operators to operate club stations. Others, such as Syria restrict all operation by foreigners to club stations only.
Amateur radio frequency allocations, in The International Telecommunication Union (ITU) governs the allocation of communications frequencies world-wide, with participation by each nation's communications regulation authority. National communications regulators have some liberty to restrict access to these frequencies or to award additional allocations as long as radio services in other countries do not suffer interference. In some countries, specific emission types are restricted to certain parts of the radio spectrum, and in most other countries, International Amateur Radio Union (IARU) member societies adopt voluntary plans to ensure the most effective use of spectrum.In a few cases, a national telecommunication agency may also allow hams to use frequencies outside of the internationally allocated amateur radio bands. In Trinidad and Tobago, hams are allowed to use a repeater which is located on 148.80 MHz. This repeater is used and maintained by the National Emergency Management Agency (NEMA), but may be used by radio amateurs in times of emergency or during normal times to test their capability and conduct emergency drills. This repeater can also be used by non-ham NEMA staff and REACT members. In the U.S., in cases of emergency, amateur radio operators may use any frequency including those of other radio services such as police and fire communications and the Alaska statewide emergency frequency of 5165.7 kHz.
Similarly, amateurs in US may apply to be registered with the Military Affiliate Radio System (MARS). Once approved and trained, these amateurs also operate on US Government Military frequencies to provide contingency communications and morale message traffic support to the military services.

Two way radio Communication.

Amateur radio (two way radio)

2007-09-14T10:49:00.000-07:00

Amateur Radio Or Ham Radio.

Term "amateur" is not a reflection on the skills of the participants, which are often quite advanced; rather, "amateur" indicates that amateur radio communications are not allowed to be made for commercial or money-making purposes. Amateur radio, often called ham radio, is both a hobby and a service that uses various types of radio communications equipment to communicate with other radio amateurs for public service, recreation and self-training. A participant is called an amateur radio operator, or a ham.
Radio amateurs use various modes of transmission to communicate. Voice transmissions are most common, with some such as frequency modulation (FM) offering high quality audio, and others such as single sideband (SSB) offering more reliable communications when signals are marginal and bandwidth is restricted.Modern personal computers have led to a boom in digital modes such as radioteletype, which previously required cumbersome mechanical equipment.Hams led the development of packet radio, which has even used protocols such as TCP/IP since the 1970s. This has since been augmented by more specialized modes such as PSK31 to facilitate real-time, low-power communications on the shortwave bands. Echolink using Voice over IP technology has enabled amateurs to communicate through local internet-connected repeaters and radio nodes, while IRLP has allowed easy linking together of repeaters. Other modes, such as FSK441 using software such as WSJT, are used for weak signal modes including meteor scatter and moonbounce communications.
Communication satellites called OSCARs (Orbiting Satellite Carrying Amateur Radio) can be accessed, some using a handy-talkie (HT) with a stock "rubber duck" antenna. Hams also use natural satellites such as the moon and the ionized trails of meteors as reflectors of radio waves. Hams are also often able to make contact with the International Space Station (ISS), as many astronauts and cosmonauts are licensed as Amateur Radio Operators.Amateur radio operators use their amateur radio station to make contacts with individual hams as well as participating in round table discussion groups or "rag chew sessions" on the air. Some join in regularly scheduled on-air meetings with other amateur radio operators, called "Nets" (as in "networks") which are moderated by a station referred to as "Net Control". Nets can allow operators to learn procedures for emergencies, be an informal round table or be topical, covering specific interests shared by a group. Find The Best Two way radio.

CB Two Way Radio

2007-09-14T10:26:00.000-07:00

Two way Radio. Similar radio services exist in other countries around the world. Frequencies, power levels, and modes (such as FM, AM and SSB) may vary from country to country, and usage of foreign equipment may be illegal. However, many countries have adopted the American frequencies.

In Canada, the "General Radio Service" has the identical frequencies and modes as the United States "Citizen's band", and no special provisions are required for either Canadians or Americans using CB gear while traveling across the border. In Europe, the CEPT adopted the North American channel assignments, except that FM is used instead of AM. Some member countries permit additional modes and frequencies. Before CEPT, most of the member countries used some subset of the 40 USA channels.

The United Kingdom, on the other hand, originally had 40 unique 27 MHz channels, known as the 27/81 Bandplan.CB two Way Radio In UK, CB became legal in the United Kingdom on November 2nd, 1981; hence the logo stamped on all type approved radios of this era CB27/81 or CB934/81. As of 8th December 2006, no licence is required to own or operate a CB Radio, Providing it meets the original legal specifications for UK usage. FM only, 4 watts power output and operating on either of the UK allowed 27 MHz bands. In the run up to legalisation, some people wanted the old VHF bomber frequency around 220 MHz (unused since WW2) for UK CB. This would have offered much better conditions for CB: nice clear channels without the chronic overseas interference there is on 27 MHz. This interference is often so severe, it even stops local contacts from being made. However, the vast majority of users were not technically minded enough to realise what a bad slot 27 MHz was, and had already purchased American-sourced equipment, so the preferred option for legalisation was the U.S. 27 MHz AM system. While technically this was one of the poorest possible choices for a short range person-to-person radio system, and was already allocated for other services, the CB community lobbied vociferously for it. The final legalised service was a compromise - a band at 27 MHz was allocated but using FM and offset channel frequencies 27.60125 - 27.99125 MHz which were incompatible with the U.S. system. There are three channels that have a specific use in the UK: Channel 9: The emergency calling channel, Channel 14: Calling channel, Channel 19: Truckers' channel and secondary calling channel.

...As of 8th December 2006, Two Way CB Radio now joins PMR446 radio under the category of licence-free personal communications. As a result, reports have been made of a significant increase in CB activity across the country. Coincidentally, several new CB Radios have recently been introduced to the UK market and their popularity with traditional CB users, such as truckers and farmers, combined with a prolific advertising campaign in Amateur Radio magazines sold in the high street, is resulting in a significant number of sales. Gets Two way Radio For best and Low Cost Communication.

Two Way Radio CB

2007-09-14T10:03:00.001-07:00

Two Way radio Citizens Band radio and short CB, In many countries, CB does not require a license and, unlike amateur radio, it may be used for commercial communication. Two way radio CB in most countries, a system of short-distance, simplex radio communications between individuals on a selection of 40 channels within the 27 MHz (11 meter) band. The CB radio service should not be confused with FRS, GMRS, MURS, or amateur ("ham") radio. Similar personal radio services exist in other countries, with varying requirements for licensing and differing technical standards.

The Citizens Band radio service originated in the United States as one of several personal radio services regulated by the FCC. Citizens' Band (CB) radio service is intended to be a private two-way voice communication service for use in personal and business activities of the general public. Its communications range is from one to five miles (1.6 to 8 kilometres). The Citizens' Band radio services are described in part 95 of the Federal Communications Commission's (FCC) and is defined as a personal radio service. . The originally, CB was located in the 460-470 MHz UHF band. There were two classes of CB: A and B. Class B radios had simpler technical requirements but were limited to a smaller range of frequencies. Al Gross, inventor of the walkie-talkie, started Citizen's Radio Corp. in the late 1940s to merchandise Class B handhelds for the general public.Over time, several countries have created similar radio services. While they may be known by other names, such as General Radio Service in Canada, they often use similar frequencies (26 to 28 MHz), and have similar uses, and similar issues with antennas and propagation. Licenses may or may not be required, but eligibility is generally simple. and Some countries have personal radio services in the UHF band, such as the European PMR446 and the Australian UHF CB.CB In Australi, Before CB was authorized in Australia, there were 27 MHz "handphones" which are authorized on several frequencies in between the present CB channels, such as 27.240 MHz. By the mid-1970s, hobbyists were experimenting with these handheld radios, as well as with unauthorized American CB radios. At that time in Australia, the 11 meter band was still used by licensed ham operators but not yet available for CB-type use. In 1977, CB was legalized with an 18-channel bandplan, and later in 1980 the American 40-channel bandplan was adopted. From the outset, the Government attempted to regulate CB radio with licence fees and call-signs etc, but some years later abandoned this approach.
After peaking in the 1970s and early 1980s, the use of 27 MHz CB in Australia has fallen dramatically in the last decade. The later introduction of 477 MHz UHF CB, with FM and repeaters, and the proliferation of cheap, compact handheld UHF transceivers have been part of the reason.
In Indonesia, CB radios were first introduced around 1977 when some transceivers were imported illegally from Australia, Japan and the United States. The dates are hard to confirm accurately but certainly early use was known around big cities such as Jakarta, Bandung, Yogyakarta, Surabaya and Medan.Indonesian Government legalized CB on October 6, 1980 through a decision of the Minister of Communications called the Ministerial Decree on the Licensing for the Operation of Inter-Citizens Radio Communication. Because many people were already using 40-channel radios prior to legalization, the American bandplan, with AM and SSB, was adopted; a VHF band was added later in 1994. On November 10, 1980, the Indonesian Directorate General of Posts and Telecommunications issued another decree establishing RAPI (Radio Antar Penduduk Indonesia) as the official citizens band radio organization in Indonesia.

Trunk Two Way Radio

2007-09-14T09:49:00.000-07:00

Unide or Yaesu Icom Motorola or Kenwood for two way radio and Equipment.

Two Way Trunked radio systems differ from (conventional) radio systems in that a conventional radio system uses a dedicated channel (frequency) for each individual group of users, while "trunking" radio systems use a pool of channels which are available for a great many different groups of users.TWo Way Trunk radio systems, For example, if police communications are configured in such a way that twelve conventional channels are required to permit citywide dispatch based upon geographical patrol areas, during periods of slow dispatch activity much of that channel capacity is idle. In a trunked system, the police units in a given geographical area are not assigned a dedicated channel, but instead are members of a talk-group entitled to draw upon the common resources of a pool of channels.Trunked radio system is a complex type of radio system that is used to maximize available capacity in a two-way radio system, usually UHF. Groups of users are given a logical talkgroup to share for their communications, rather than a dedicated radio frequency.

Two way radio trunking is used by many government entities to provide two-way communication for fire departments, police and other municipal services, who all share spectrum allocated to a city, county, or other entity. Trunked radio takes advantage of the probability that in any given number of user units, not everyone will need channel access at the same time. Therefore with a given number of users, fewer discrete radio channels are required. From another perspective, with a given number of radio channels, a much greater number of user groups can be accommodated. In the example of the police department, this additional capacity could then be used to assign individual talk groups to specialized investigative, traffic control, or special-events groups who might otherwise not have the benefit of individual private communications.

To the user, a trunking radio looks just like an "ordinary" radio: there is a "channel switch" for the user to select the "channel" that they want to use. In reality though, the "Channel switch" is NOT switching channels at all: when changed, it refers to an internal software program which causes a talkgroup affiliation to be broadcast on the control channel. This identifies the specific radio to the system controller as a member of a specific talkgroup, and that radio will then be included in any conversations involving that talkgroup. ..and find Best two way radio.

GMRS Two Way Radio

2007-09-14T09:34:00.000-07:00

Communication With Two way radio, like from Motorola, Icom, Vertex Two Way Radio, Yaesu and etc.

GMRS Two Way Radio or General Mobile Radio Service, was originally named Class A Citizens Radio Service when it was rolled out in the 1960s. Tube type transceivers were used and output power was limited to 60 watts plate input power to the final amplifier tube. The original service ran wideband FM with ±15 kHz transmitter deviation and 50 kHz channel spacing. At the time, this was the norm for all U.S. land mobile services. There was also a Class B Citizens Radio Service which used a different set of 461 MHz channels and was limited to 5 watts output. Business users were permitted to license in this radio service. Radios were built by consumer electronics firms and commercial two-way radio vendors.GMRS Two Way radio is a land-mobile UHF radio service in the United States available for short-distance two-way communications to facilitate the activities of an adult individual who possesses a valid GMRS license, as well his or her immediate family members, including a spouse, children, parents, grandparents, aunts, uncles, nephews, nieces, and in-laws (47 CFR 95.179). Immediate relatives of the GMRS system licensee are entitled to communicate among themselves for personal or business purposes, but employees of the licensee, who are not family members, may not use this service.GMRS radios are typically handheld portable devices much like Family Radio Service (FRS) radios, and share some frequencies with FRS. Mobile and base station-style radios are available as well, but these are normally commercial UHF radios often used in the public service and commercial land mobile bands. These are legal for use in this service as long as they are GMRS type-approved. They are more expensive than the walkie talkies typically found in discount electronics stores, but are higher quality, in other countries have personal radio services with somewhat similar characteristics, but technical details and operating conditions vary according to national rules. Many European (uk, france,italy, and germany and etc) countries use a similar 8 channel system near 446MHz known as PMR446.

The GMRS Two Way Radio In Canada. hand-held GMRS radios up to 2 watts have been approved for use since September 2004. Typically these are dual FRS and GMRS units, with fixed antennas, and operating at 2 watts on GMRS and 0.5 watts on the FRS-only channels. A license is not required in Canada for operation at 2 watts on the GMRS channels. Mobile units (permanently mounted in vehicles), base stations and repeaters are not currently permitted on the GMRS channels in Canada.

Two Way Radio In Europe

2007-09-14T09:21:00.000-07:00

Two Way radio In Europe (FSR), a personal radio service with the same sort of licensing restriction is PMR446 having eight channels in the 446MHz range. One cannot legally use the FRS radio in Europe or PMR446 in the U.S. The 446 MHZ band is allocated to amateur radio in US, so in principle a licensed amateur operator could use non-FCC-type-accepted PMR446 radios in the US. in compliance with the rules for amateur radio operation. In Great Britain (UK), FRS frequencies are used for fire brigade communications and this sometimes causes problems when FRS equipment is imported from the US and used without awareness of the consequences by members of the public.
Two way radio Dual-mode GMRS/FRS equipment is also approved in most South American countries and Brazil. Portable radios are heavily used in private communications, mainly by security staff in nightclubs and malls, but also in private parking, maintenance and delivery services.
A service similar to the American-style FRS in Hong Kong, China and Macau is also approved by respective organizations for legal license-free operation. However, different UHF frequencies with 20 allocated channels near 409 MHz are used. 462 MHz and 446 MHz band are not opened to FRS service, so European, U.S. and Canada residents are advised not to use FRS or PMR446 radios for communication when traveling to the mentioned areas.
In Japan, a similar service uses low-power in the 420, 421, 422 MHZ bands. In Australia and New Zealand, the UHF CB citizen's band near 477 MHZ is used for a similar purpose. Find Best two Way Radio In europe like in UK or France, Italy, Spain, Germany, and etc.

FSR GMRS Two way Radio In US

2007-09-14T09:09:00.000-07:00

FRS And GMRS For Best Two Way radio Communication.

The Two Way Radio with hybrid FRS and GMRS consumer radios have been introduced that have 22 channels. Many of these radios have been certified for unlicensed operation (on the 14 FRS frequencies) under FRS rules. The FCC rules and statements regarding the use of hybrid radios on channels 1-7 stipulate the need for GMRS licensing only when operating under the RULES that apply to the GMRS. Many hybrid radios have an ERP that is lower than 1/2 watt on channels 1-7, or can be set by the user to operate at low power on these channels. This allows hybrid radios to be used under the license free FRS rules if the ERP is less than 1/2 watt AND the unit is certified for FRS operation on these frequencies.Channels 8-14 are reserved exclusively for the FRS, and GMRS operation is not allowed on these channels.Channels 15-22 are reserved exclusively for GMRS, and FRS operation is not allowed on these channels.Services similar to the American FRS exist in other countries, although since technical standards and frequency bands may differ, usually FCC-approved FRS equipment may not be used in other jurisdictions.
American (USA) standard Two Way FRS radios have been approved for use in Canada since April 2000. The revised technical standard RSS 210 has essentially the same technical requirements as in the United States. Since September 2004 low-power GMRS radios and dual-standard GMRS and FRS radios have also been approved for use in Canada, giving additional channels.And Since tourists often bring their Two Way FRS radios with them, and since trade between the U.S., Canada, and Mexico is of great value to all three countries, the Mexican Federal Telecommunications Commission has authorized use of the FRS frequencies and equipment similar to that in the US. However, dual-mode GMRS and FRS equipment is not approved in Mexico, so caution should be exercised in operating FRS devices purchased elsewhere.

Two Way Radio In US

2007-09-13T12:58:00.000-07:00

Two Way Radio Family Radio Service IN USA. A FRS radios are limited to 500 milliwatts in the U.S., according to FCC regulations. Channels 1 to 7 are shared with low-power interstitial channels of GMRS, the General Mobile Radio Service. A license is required for those channels only if the power output is over FRS limits, up to GMRS limits. Unlike Citizens' Band (CB) radios, FRS radios frequently have provisions for using sub-audible tone squelch (CTCSS and DCS) codes, filtering out unwanted chatter from other users on the same frequency. Though these codes are sometimes called "privacy codes" or "private line codes" (PL codes), they offer no protection from eavesdropping and are only intended to help share busy channels. Tone codes also do nothing to prevent desired transmissions from being swamped by stronger signals having a different code.
FRS stations on channels 1 through 7 may communicate with GMRS stations on those channels; the GMRS stations may use up to 5 watts of power while the FRS stations are restricted to 0.5 watt.
The use of duplex radio repeaters and interconnects to the telephone network are prohibited under FRS rules, unlike in GMRS, where repeaters but not telephone interconnect are permitted, and the Amateur Radio Service. FRS radios must use only permanently-attached antennas. This limitation intentionally restricts the range of communications, and promotes sharing of the available channels.
FRS manufacturers generally claim an effective range of 3 km (2 miles) or more, but actual performance is limited by the physics of propagation. The presence of large buildings can reduce range. Under exceptional conditions, like hill-top to hill-top, communication is possible over 50 km (30 miles) or more. Under normal conditions with line-of-sight blocked by a few buildings or trees, FRS generally has an effective range of 0.5 to 1.5 km (1/3 to 1 mile). Buyers should beware of the fanciful claims of FRS manufacturers who claim range of up to 18 miles; it simply isn't possible except in exceptional conditions with clear line of sight. Finds The Best Two Way Radio (FRS) In US...

Two Way Radio Types FSR GMRS

2007-09-13T12:47:00.000-07:00

FRS Two way Radio, or Family Radio Service (FRS) is an improved walkie talkie/Handie talkie system authorized in the United States since 1996. FSR is conventional Two way radio System and this personal radio service uses frequencies in the ultra high frequency (UHF) band, and so does not suffer the interference effects found on citizens' band (CB) at 27 MHz, or the 49 MHz band also used by cordless phones, toys, and baby monitors. FRS uses frequency modulation (FM) instead of amplitude modulation (AM), and has a greater reliable range than license-free radios operating in the CB or 49 MHz bands.
Initially proposed by Radio Shack in 1994 for use by families, FRS has also seen significant adoption by business interests, as an unlicensed, low-cost alternative to the business band.FRS Two way radios are limited to 500 milliwatts in the U.S., according to FCC regulations. Channels 1 to 7 are shared with low-power interstitial channels of GMRS, the General Mobile Radio Service. A license is required for those channels only if the power output is over FRS limits, up to GMRS limits. Unlike Citizens' Band (CB) radios, FRS radios frequently have provisions for using sub-audible tone squelch (CTCSS and DCS) codes, filtering out unwanted chatter from other users on the same frequency. Though these codes are sometimes called "privacy codes" or "private line codes" (PL codes), they offer no protection from eavesdropping and are only intended to help share busy channels. Tone codes also do nothing to prevent desired transmissions from being swamped by stronger signals having a different code.
FRS stations on channels 1 through 7 may communicate with GMRS stations on those channels; the GMRS stations may use up to 5 watts of power while the FRS stations are restricted to 0.5 watt. The use of duplex radio repeaters and interconnects to the telephone network are prohibited under FRS rules, unlike in GMRS, where repeaters but not telephone interconnect are permitted, and the Amateur Radio Service. FRS radios must use only permanently-attached antennas. This limitation intentionally restricts the range of communications, and promotes sharing of the available channels.Communication withTwo way radio FSR and GMRS..

Two Way Radio Marine Types

2007-09-13T12:39:00.000-07:00

The Two Way Radio; Marine VHF radio is installed on all large ships and most motorized small craft. It is used for a wide variety of purposes, including summoning rescue services and communicating with harbours and marinas, and operates in the VHF frequency range, between 156 to 174 MHz. Although it is widely used for collision avoidance, its use for this purpose is contentious and is strongly discouraged by some countries, including the UK.
marine VHF set is a combined transmitter and receiver and only operates on standard, international frequencies known as channels. Channel 16 (156.8 MHz) is the international calling and distress channel. Channel 9 can also be used in some places as a secondary call and distress channel. Transmission power ranges between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles (111 km) between aerials mounted on tall ships and hills, and 5 nautical miles (9 km) between aerials mounted on small boats at sea-level. Frequency modulation is used.
A Marine VHF mostly uses (simplex) transmission, where communication can only take place in one direction at a time. A transmit button on the set or microphone determines whether it is operating as a transmitter or a receiver. The majority of channels, however, are set aside for (duplex) transmissions channels where communication can take place in both directions simultaneously, and each duplex channel has two frequency assignments. This is mainly because, in the days before mobile phones and satcomms became widespread, the duplex channels could be used to place calls on the public telephone system for a fee via a marine operator. This facility is still available in some areas, though its use has largely died out. In US waters, Marine VHF radios can also receive weather radio broadcasts, where they are available, on receive-only channels wx1, wx2, and etc. Finds Best Marine Two way Radios

Two Way Radio Types

2007-09-13T12:27:00.000-07:00

There is an array of two-way radio technologies, systems, and types. There are families of radio types and each family has differing sub-groups and specific radio models. Conventional and trunked Simplex and duplex channels, Hybrid simplex/duplex , Push-to-talk, Analog and digital.

...Two way radio technologies, systems, and types the Conventional Two way radio: Conventional radios operate on fixed RF channels. In the case of radios with multiple channels, they operate on one channel at a time. The proper channel is selected by a user. The user operates a channel selector or buttons on the radio control panel to pick the channel.
In multi-channel systems, channels are used for separate purposes. A channel may be reserved for a specific function or for a geographic area. In a functional channel system, one channel may allow City of Springfield road repair crews to talk to the City of Springfield's road maintenance office. A second channel may allow road repair crews to communicate with state highway department crews. In a geographic system, a taxi company may use one channel to communicate in the Boston, Massachusetts area and a second channel when taxis are in Providence, Rhode Island. In marine radio operations, one channel is used as an emergency and calling channel, so that stations may make contact then move to a separate working channel for continued communication.
Scanning in conventional radios, in some conventional radios scan more than one channel. That is, the receiver searches more than one channel for a valid transmission. A valid transmission may be a radio channel with any signal or a combination of a radio channel with a specific CTCSS (or Selective calling) code.There are a wide variety of scan configurations which vary from one system to another. Some radios have scan features that receive the primary selected channel at full volume and other channels in a scan list at reduced volume. This helps the user distinguish between the primary channel and others without looking at the radio control panel. An overview:A scanning feature can be defined and preset: when in scanning mode, a predetermined set of channels is scanned. Channels are not changeable by the radio user.

Some Two Way radios allow an option for user-selected scan: this allows either lockout of pre-selected channels or adding channels to a scan list by the operator, and this may revert to a default scan list each time it is powered off or may permanently store the most recent changes. In professional Two way radios, scan features are programmable and have many options. Scan features can affect system latency. If the radio has a twenty channel scan list and some channels have CTCSS, it can take several seconds to search the entire list. The radio must stop on each channel with a signal and check for a valid CTCSS before resuming scanning. This can cause missed messages.For this reason, scan features are either not used or scan lists are intentionally kept short in emergency applications. Part of APCO Project 16 set standards for channel access times and delays caused by system overhead. Scan features can further increase these delays. Talk-back on scanSome conventional radios use, or have an option for, a talk-back-on-scan function. If the user transmits when the radio is in a scan mode, it may transmit on the last channel received instead of the selected channel. This may allow users of multi-channel radios to reply to the last message without looking at the radio to see which channel it was on. Without this feature, the user would have to use the channel selector to switch to the channel where the last message occurred.

Two Way Trunk communication

2007-09-13T12:17:00.000-07:00

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Technologies, systems, and types : Trunk Two Way Radio, on a trunked Two way radio system, the system logic automatically picks the physical radio frequency channel. There is a protocol that defines a relationship between the radios and the radio backbone which supports them. The protocol allows channel assignments to happen automatically.
Digital trunked systems may carry simultaneous conversations on one physical channel. In the case of a digital trunked radio system, the system also manages time slots on a single physical channel. The function of carrying simultaneous conversations over a single channel is called multiplexing.
Instead of channels, radios are related by groups which may be called, groups, talk groups, or divided into a hierarchy such as fleet and subfleet, or agency-fleet-subfleet. These can be thought of as virtual channels which appear and disappear as conversations occur.
Systems make arrangements for handshaking and connections between radios by one of these two methods:
A computer assigns channels over a dedicated control channel. The control channel sends a continual data stream. All radios in the system monitor the data stream until commanded by the computer to join a conversation on an assigned channel. Electronics embedded in each radio communicate using a protocol of tones or data in order to establish a conversation, (scan-based). If all physical channels are busy, some systems include a protocol to queue or stack pending requests until a channel becomes available.
Some trunked radios scan more than one talk group or agency-fleet-subfleet.
Visual clues a radio may be trunked include the 1) lack of a squelch knob or adjustment, 2) no monitor button or switch, and 3) a chirp (made infamous by Nextel) showing the channel is available and ready at the moment the push-to-talk is pressed. others trunk System Logic Trunked Radio and EDACS .

System Two way radios

2007-09-13T12:11:00.000-07:00

Two-way radio technologies, systems, and types: Simplex channel systems and Duplex systems:
Simplex channel systems use a single channel for transmit and receive. This is typical of aircraft VHF AM and marine radios. Simplex systems are often legacy systems that have existed for years or decades. The architecture allows old radios to work with new ones in a single network. In the case of all ships worldwide or all aircraft worldwide, the large number of radios installed, (the installed base,) can take decades to upgrade. Simplex systems often use open architectures that allow any radio meeting basic standards to be compatible with the entire system.
Advantage: as the simplest system configuration, there is reliability from the fact that only two radios are needed to establish communication between them. Disadvantages: The simplex configuration offers communication over the shortest range or distance because mobile units must be in effecitve range of each other. The available channel bandwidth limits the number of simultaneous conversations, since "dead" air time cannot be easily used for additional communication.

Duplex means two channels are used: one in each direction.Duplex channel systems transmit and receive on different discrete channels. This defines systems where equipment cannot communicate without some infrastructure such as a repeater or base station. Most common in the US is a repeater configuration where a base station is configured to re-transmit the audio received from mobile units. This makes the mobiles, or hand-helds, able to communicate amongst one another anywhere within reception range of the base station or repeater. Typically the base or repeater station has a high antenna, which allows greater range, compared with a ground vehicle or hand-held transceiver.
Duplex systems can be divided into two types. The term half-duplex refers to systems where use of a push-to-talk switch is required to communicate. Full duplex refers to systems like mobile telephones with a capability to simultaneously receive and transmit.
Advantage: duplex channels usually allow repeater operation which extends range - especially where hand-held radios are in use. Disadvantage: If a radio cannot reach the repeater, it cannot communicate. Best two Way Radio

Communication Two way

2007-09-13T12:05:00.000-07:00

Two way radio technologies, systems, and types : Push-to-talk
...In one Motorola system, a Special Products microphone was created with a rocker-style push-to-talk button. The microphone looked like a normal mobile microphone except that the button rocked either up or down instead of pressing in. Rocking the switch in one direction transmitted duplex on a repeater; the other transmitted simplex on car-to-car.
In two-way radios with headsets, a push-to-talk button may be included on a cord or wireless electronics box clipped to the user's clothing. In an ambulance or aircraft, a button may be present where the corded headset plugs in to the radio wiring. Dispatch consoles often have a hand-operated push-to-talk buttons along with a foot switch or pedal. If the dispatcher's hands are on a computer keyboard, the user can step on the foot pedal to transmit. Some systems have muting so the dispatcher can be on a telephone call and the caller cannot hear what is said over the radio. Their headset microphone will mute if they transmit. This relieves the dispatcher of explaining every radio message to a caller.
In some circumstances, voice-operated transmit (VOX) is used in place of a push-to-talk button. Possible uses are handicapped users who cannot push a button, Amateur radio operators, firefighters, crane operators, or others performing critical tasks where hands must be free but communication is still necessary. find Best Two Way Radios

Communication With radio

2007-09-13T11:51:00.000-07:00

Two way Radio. There is an array of two-way radio technologies, systems, and types...Analog and digital.

The Advantage : More simultaneous talking paths are possible and information such as unit ID, status buttons, or text messages can be embedded into a single digital radio channel. Disadvantage: Radios must be designed to the same, compatible standard, radios can become obsolete quickly, cost more to purchase, and are more complicated.
Two Way radio Analog systems may communicate a single condition, such as water level in a livestock tank. A transmitter at the tank site continually sends a signal with a constant tone. Tone would change in pitch to indicate the tank's water level. A meter at the remote end would vary, corresponding to the pitch, to indicate the amount of water present in the livestock tank. Similar methods can be used to telemeter any analog condition. This type of radio system serves a purpose equivalent to a four-to-twenty milliampere loop. In the US, mid-band 72-76 MHz or UHF 450-470 MHz interstitial channels are often used for these systems. Some systems multiplex telemetry of several analog conditions by limiting each to a separate range of tone pitches, for example.
Two Way radio Digital systems may communicate text from computer-aided dispatch or CAD. For example, a display in a tow truck may give a textual location for a call and any related details. The tow truck driver may press an acknowledge button, sending data in the opposite direction and flagging the call as received by the driver. They can be used for analog telemetry systems, such as livestock tank levels, as described above. Analog conditions are translated into data words. Some systems send radio paging messages which can either 1) beep a paging receiver, 2) send a numeric message, or 3) send a text message.Digital systems typically use data rates in the 1,200-19,200 kilobit-per-second rates and may employ modulation schemes such as frequency shift keying, audio frequency shift keying, or quadrature phase shift keying to encode characters. Modern equipment have the same capabilities to carry data as are found in Internet Protocol. Working within the system's protocol constraints, virtually anything can be sent or received.

Two Way Radio

2007-09-11T15:17:00.000-07:00

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Two way radio is a radio that can both transmit and receive (a transceiver), unlike a broadcast receiver which only receives content one way. A push to-talk or (Press To Transmit) button is often present to activate the transmitter. Hand-held portable two-way radios are often called walkie-talkies or handie-talkies and also available in mobile and stationary base (like fixed station two way radio) configurations.An example of two way radio that both transmits and receives at the same time (or full-duplex) is a mobile phone or cellular telephone, which uses two different radio frequencies to carry the two directions of the conversation simultaneously.

Two way Radio

2007-09-11T14:59:00.000-07:00

A Two way radio and for best communication. two way radio for pro or amateur,

Breif History 2 Way Radio:

Bayonne New Jersey (1933) police department successfully operated a two way radio system between a central fixed station and radio transceivers installed in police cars; this allowed rapidly directing police response in emergencies. And During World War II hand-held radio transceivers were extensively used by air and ground troops.
And early two way radio schemes allowed only one station to transmit at a time while others listened, since all signals were on the same radio frequency (was called 'simplex' mode). Code and voice operations required a simple communication protocol to allow all stations to cooperate in using the single radio channel, so that one station's transmissions were not obscured by another's. By using receivers and transmitters tuned to different frequencies, and solving the problems introduced by operation of a transmitter immediately next to a transmitter, simultaneous transmission and reception was possible at each end of a radio link, (in so-called 'full duplex' mode).
Early two-way schemes required training operators to learn and use Morse code; in ship-board installations the radio operating officer typically had no other duties than handling radio messages. When voice transmission became possible, dedicated operators were no longer required and two-way use became more common. Today's two-way mobile radio equipment is nearly as simple to use as a household telephone, from the point of view of operating personnel, thereby making two-way communications a useful tool in a wide range of personal, commercial and military roles.

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In 1933, the police department in Bayonne New Jersey initiated regular two-way communications with its patrol cars, a major advance over previous one-way systems. is very high frequency system developed by radio engineer Frank A. Gunther and station operator Vincent J. Doyle placed transmitters in patrol cars to enable patrolmen to communicate with headquarters and other cars instead of just receiving calls. Two-way police radio became standard throughout the country following the success of the Bayonne system.
In March 1933, the first two-way AM mobile radio was installed in a patrol car of the Bayonne Police Department. The system was designed by Lieutenant Vincent J. Doyle of the Bayonne Police and radio engineer Frank Gunther. Through the use of a combined transmitter and receiver in the patrol car, the two-way system allowed communication between patrol cars and with the police station.
The Bayonne system was developed less than five years after the deployment of the one-way AM mobile-radio system by the Detroit Police Department. On April 7, 1928, the Detroit Police commenced regular one-way radio communication with its patrol cars, using a system developed by Patrolman Kenneth Cox and Robert L. Batts, an engineering student. This system proved the practicality of land-mobile radio for police work and led to its adoption throughout the county.

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TWO Way radios::

2007-09-11T12:28:00.000-07:00

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