Telescoping Antenna Mast

220 MHz Yagi Antennas the 7 Things You Must Know Before You Buy Your Next One

admin — Sat, 21 Aug 2010 08:29:40 +0000

Every year thousands of antennas fail due to high wind, heavy snow, ice loading and other severe weather situations. 220 MHz antennas, because of their large physical size, are particularly vulnerable to weather related failure.

That’s not all: when you combine these reliability issues with your performance expectations (you want the antenna to perform reliably for many years, right?) your choice of antenna manufacturer for 220 MHz applications becomes especially important.

This clearly isn’t the place to try and save $5 on an antenna or base your buying decision on “it’s the brand we’ve always used” or because “the vendor’s in our system”.

Let’s face it, antenna failures represent a totally unnecessary inconvenience and expense for system operators. The high cost of travel and manpower to replace a failed unit far exceeds any saving realized on the initial purchase of an ‘economy’ antenna.

You want to install the antenna once and forget about it. Right?

So to help make sure we get it right the first time, here are the 7 things you must know before you buy your next 220 MHz Yagi antenna:

1. Material. Insist on an aircraft quality 6061-T6 aluminum frame. This is strong and light. The boom (mast) should have a minimum of 11/2″ OD material with heavy duty ¾” elements and dipole. Remember, this antenna has to survive severe wind, often times with ice and frost build up.

2. Manufacturing. All components should be machined on CNC equipment for consistency and precision. This ensures every antenna is a clone of the next. You can depend on the performance to be exactly the same from antenna to antenna.

3. Construction. Insist on fully TIG-welded construction for the entire antenna. TIG welding provides vital strength and the antenna becomes electrically one piece. Forget bolted together antennas and antennas with bolted on brackets for this frequency.

4. Finish. Black anodized or black thermoset Polymer Coating (Powder coated). This helps reduce ice build up and protects against environmental degradation. Anodizing is the best here but the thermoset polymer is an excellent second. The black color absorbs heat and helps melt any ice or hoar frost that builds up on the antenna.

5. Feedline. Purchase your antennas with the correct length feedline built into the antenna right from the factory. Factory installed, sealed and tested integral feedlines offer many benefits and completely eliminate the requirement for field installed feed cables. This is especially wonderful for cookie cutter installations. You take the antenna out of the box and it’s installed in less that 15 minutes. There’s no feedline to build and install!

6. Mounting hardware. A heavy duty steel bracket that easily permits horizontal or vertical polarization should be included with the antenna. You also want a hot dipped galvanized bracket with minimum ½” galvanized bolts (not stainless steel). Remember, these are big antennas with high wind loading. A wimpy, light duty bracket can’t cut it at the 220 MHz frequency.

7. Warranty. The Antenna should come with a minimum 5 year warranty. If it’s built right then the manufacturer should stand behind it. If it doesn’t have at least a 5 year warranty you should be asking: why?

8. (Free Bonus Tip) be sure to insist that each and every antenna is tested and certified by the manufacture prior to shipping! Nothing worse that getting to the install site and having a DOA antenna.

If you consider the above recommendations when choosing your next 220 MHz Yagi antennas, your end result will be drastically improved reliability and improved system performance. Besides, who needs a phone call on your day off, telling you that an antenna has failed and the system is down. I know you don’t want to take that call and it definitely won’t be you if you heed these recommendations

Good wireless can become GREAT using optimum antenna technology incorporated into the design from the start. Click here http://wavelinkantenna.com to see what great antenna options Wavelink Antenna Systems offers. Gary Tootle advises and supports wireless communications professionals throughout USA and Canada http://www.wavelinkantenna.com/contact.php

Electricity Pylon

admin — Fri, 20 Aug 2010 13:21:49 +0000

High voltage AC transmission towers

Electricity pylons over water, near Darwin, Northern Territory, Australia

Three-phase electric power systems are used for high and extra-high voltage AC transmission lines (50 kV and above). The towers must be designed to carry three (or multiples of three) conductors. The towers are usually steel lattices or trusses (wooden structures are used in Germany and Scandinavia in some cases) and the insulators are either glass or porcelain discs or composite Insulators using Silicone Rubber or EPDM rubber material assembled in strings or long rod whose length is dependent on the line voltage and environmental conditions. One or two earth conductors (or “ground conductors”) for lightning protection are often mounted at the top of each tower.

In some countries, towers for high and extra-high voltage are usually designed to carry two or more electric circuits. For double circuit lines in Germany, the “Danube” towers or more rarely, the “fir tree” towers, are usually used. If a line is constructed using towers designed to carry several circuits, it is not necessary to install all the circuits at the time of construction.

Some high voltage circuits are often erected on the same tower as 110 kV lines. Paralleling circuits of 380 kV, 220 kV and 110 kV-lines on the same towers is common. Sometimes, especially with 110 kV circuits, a parallel circuit carries traction lines for railway electrification.

A new type of pylon will be used in the Netherlands starting in 2010. The pylons were designed as a minimalist structure by Dutch architects Zwarts & Jansma. The use of physical laws for the design made a reduction of the magnetic field possible. Also, the visual impact on the surrounding landscape is reduced.

High voltage DC transmission pylons

HVDC Distance Pylon near the terminus of the Nelson River Bipole adjacent to Dorsey Converter Station near Rosser, Manitoba, Canada August 2005

High voltage direct current (HVDC) transmission lines are either monopolar or bipolar systems. With bipolar systems a conductor arrangement with one conductor on each side of the tower is used. For single-pole HVDC transmission with ground return, towers with only one conductor can be used. In many cases, however, the towers are designed for later conversion to a two-pole system. In these cases, conductors are installed on both sides of the tower for mechanical reasons. Until the second pole is needed, it is either grounded, or joined in parallel with the pole in use. In the latter case the line from the converter station to the earthing (grounding) electrode is built as underground cable.

Railway traction line pylons

Tension tower with phase transposition of a powerline for single phase AC traction current (110 kV, 16.67 Hz) near Bartholom, Germany

Towers used for single phase AC railway traction lines are similar in construction to those towers used for 110 kV-three phase lines. Steel tube or concrete poles are also often used for these lines. However, railway traction current systems are two-pole AC systems, so traction lines are designed for two conductors (or multiples of two, usually four, eight, or twelve). As a rule, the towers of railway traction lines carry two electric circuits, so they have four conductors. These are usually arranged on one level, whereby each circuit occupies one half of the crossarm. For four traction circuits the arrangement of the conductors is in two-levels and for six electric circuits the arrangement of the conductors is in three levels.

With limited space conditions, it is possible to arrange the conductors of one traction circuit in two levels. Running a traction power line parallel to a high voltage transmission line for three-phase AC on a separate crossarm of the same tower is possible. If traction lines are led parallel to 380 kV-lines, the insulation must be designed for 220 kV, because in the event of a fault, dangerous overvoltages to the three-phase alternating current line can occur. Traction lines are usually equipped with one earth conductor. In Austria, on some traction circuits, two earth conductors are used.

Assembly

This section requires expansion.

There are a variety of ways pylons can be assembled and erected:

They can be assembled horizontally on the ground and erected by push-pull cable. This method is rarely used, however, because of the large assembly area needed.

Gin pole crane: A gin pole crane can be used to assemble lattice towers.

Using a crane or using derrick.

Helicopter: In areas with very limited accessibility, such as mountains, assembly can be done using a helicopter.

Testing of mechanical properties

There are tower testing stations for testing the mechanical properties of towers.

Sign markings

Tower Identification Tag on HVDC anchor pylon at Dorsey Converter Station near Rosser, Manitoba, Canada August 2005

Aside from the obligatory high voltage warning sign, electricity towers also frequently possess a sign or circuit identification plate, with the names of the line (either the terminal points of the line, or the internal designation of the power company) and the tower number. This makes identifying the location of a fault to the power company that owns the tower easier.

In some countries, require that lattice steel towers be equipped with a barbed wire barrier approximately 3 metres (9.8 ft) above ground in order to deter unauthorized climbing. Such barriers can often be found on towers close to roads or other areas with easy public access, even where there is not a legal requirement. In the United Kingdom, all such towers are fitted with barbed wire.

Special designs

Hyperboloid pylon in the suburb of Nizhniy Novgorod, Russia.

Antennas for low power FM radio, television, and mobile phone services are sometimes erected on pylons, especially on the steel towers carrying high voltage cables.

To build branches, quite impressive constructions must occasionally be used. This also applies occasionally to twisting towers that divert three-level conductor cables.

Sometimes (in particular on steel framework pylons for the highest voltage levels) transmitting plants are installed. Usually these installations are for mobile phone services or the operating radio of the power supply firm, but occasionally also for other radio services, like directional radio. Thus transmitting antennas for low-power FM radio and television transmitters were already installed on pylons. On the carrying pylon of the Elbe Crossing 1 there is a radar facility belonging to the Hamburg water and navigation office.

For crossing broad valleys, a large distance between the conductor cables must be maintained to avoid short-circuits caused by conductor cables colliding during storms. Sometimes a separate pylon is used for each conductor. For crossing wide rivers and straits with flat coastlines very high pylons must be built, because a large height clearance is needed for navigation. Such masts must be equipped with flight safety lamps.

One of the Pylons of Cdiz, Spain

Two well-known wide river crossings are the Elbe Crossing 1 and Elbe Crossing 2. The latter has the highest overhead line masts in Europe, at 227 meters tall. The overhead line crossing pylons in the Spanish bay of Cdiz have a particularly interesting construction. They consist of 158-meter-high carrying pylons with one cross beam atop a frustum framework construction. The longest overhead line spans are the crossing of the Norwegian Sognefjord (4,597 meters between two masts) and the Ameralik span in Greenland (5,376 meters.) In Germany the overhead line of the EnBW AG crossing of the Eyachtal has the longest span in the country at 1,444 meters.

In order to drop overhead lines into steep, deep valleys, inclined pylons are occasionally used. An example of this type of pylon is located at the Hoover dam in the USA. In Switzerland a NOK pylon inclined around 20 degrees to the vertical is located near Sargans. Highly sloping masts are used on two 380 kV pylons in Switzerland, the top 32 meters of one of them being bent by 18 degrees to the vertical.

Power station chimneys are sometimes equipped with crossbars for fixing conductors of the outgoing lines. Because of possible problems with corrosion by the flue gases, such constructions are very rare.

Types of pylons

Specific functions

Anchor pylons (also called strainer pylons or terminal towers) are used at the endpoints of straight runs of conductors. They utilize tension insulators to carry the horizontal tension of the long stretch of line.

pine pylon an electricity pylon for two circuits of three-phase AC current, a which the conductors are arranged in three levels. In pine pylons the lowest crossbar has a wider span than that in the middle and this one a larger span than that on the top.

Transposing pylons are anchor or terminal pylons at which the conductors are “transposed” so that they exchange sides of the pylon.

Long-distance anchor pylon

Branch pylon

Anchor portal

Materials used

Wood pylon

Concrete pylon

Steel tube pylon

Lattice steel pylon

Concrete filled steel tube pylon

Stobie pole

Conductor arrangements

Portal pylon

Delta pylon

Single-level pylon

Two-level pylon

Three level pylon

Barrel pylon

Specific locations

Roof stand

Crossing pylon

bridge mounted structures, as on Storstrm Bridge

Specific purposes

Rail current pylon

Hybrid pylon

Utility pole

Pylons in art and culture

The North Korean coat of arms, bearing a pylon in the center.

In the 1998 film Among Giants, a pylon at grid reference SD833152 in Ashworth Valley, near Rochdale, Greater Manchester, England, was painted pink for the movie. The pylon was demolished in 2003.

In Ruhrpark, a big mall in Bochum, Germany, there is a pylon decorated with balls.

The North Korean official emblem has a pylon and a dam on it.

Alternatives to pylons

Pylons and the cables that they support are generally regarded to be unattractive and decrease the aesthetic value of the landscape and property values; a form of visual pollution. An alternative to pylons is underground cables. There are schemes in various countries to remove the pylons and undergrounding the cables, such as those in Europe. The US, however, continues to place most of its power lines above ground. Aside from the aesthetic value, some believe that overhead power lines are a security threat; a transmission line can be targeted by terrorists and taken out swiftly by attacking the towers. The lines being moved underground also reduces the chance of the power lines being affected by storms such as hurricanes and tornadoes, or other storms that are capable of knocking trees down on the main lines leaving substations. They also reduce the possibility of starting forest fires when the lines are broken.

One of the largest disadvantages involving burying underground cables is its cost. Some estimates state that the price can be raised by 4 to 10 times . Laying underground cables can be very expensive, especially in rocky terrain. Underground cables also have poor heat-dissipation qualities; unlike conductors suspended on towers, which are cooled by the air, the heat from underground transmission has nowhere to go and can cause damage to the cables. This can be addressed by pumping water or oil along the cable to cool it. The additional capacitance of the ground also results in less efficient power transmission. They are far more vulnerable to careless or inadvertent damage by third parties, often in the course of construction work. Burying cables also requires a large purchase of right-of-way for the transmission corridor just as pylons do; some estimates place this clearance as 30 to 50 feet (9.1 to 15 m), about the size of a three- to four-lane road.

There is the option of burying a high-voltage direct current (HVDC) as opposed to an alternating current (AC) line. However, this is a possibility which will take some time to implement in the United States, as there are no manufacturers of the cables required for this. Furthermore terminals of high-voltage direct current-systems are expensive and have no remarkable overload capacity. Beside this, there are additional losses in the inverter plants and it is difficult to operate HVDC systems with more than 2 terminals. Until now, HVDC is nearly always used for applications where an AC solution would be impossible or a technical bad solution. In fact, HVDC Kingsnorth an HVDC cable system for feeding the inner part of London, UK was replaced after 12 years by an AC system. Although HVDC is well suited for cable transmission and often used for submarine power cables, there are also many HVDC overhead lines ( see List of HVDC projects).

Pylons of special interest

Pylon

Year

Country

Town

Pinnacle height

Remarks

Yangtze River Crossing

2003

China

Jiangyin

346.5m

Tallest pylons in the world

Yangtze River Crossing Nanjing

1992

China

Nanjing

257 m

Tallest pylons in the world, built of reinforced concrete

Pylons of Pearl River Crossing

1987

China

253 m + 240 m, 830 ft + 787 ft

Orinoco River Crossing

Venezuela

Caron

240 m

Tallest electricity pylons in South America

Pylons of Messina

1957

Italy

Messina

232 m ( 224 m without basement)

no longer used as pylons

HVDC Yangtze River Crossing Wuhu

2003

China

Wuhu, Anhui Province

229 m

Tallest electricity pylons used for HVDC

Elbe Crossing 2

1976-1978

Germany

Stade

227 m

tallest electricity pylons in Europe

Chusi Powerline Crossing

1962

Japan

Chusi

226 m

Tallest electricity pylons in Japan

Daqi-Channel-Crossing

1997

Japan

223 m

Overhead line crossing Suez Canal

1998

Egypt

221 m

LingBei-Channel-Crossing

1993

Japan

214.5 m

Kerinchi Pylon

1999

Malaysia

Kerinchi near Kuala Lumpur

210 m

Tallest pylon in Southeast Asia

Luohe-Crossing

1989

China

202.5 m

pylons of reinforced concrete

380kV Thames Crossing

1965

West Thurrock

190 m

Elbe Crossing 1

1958-1962

Germany

Stade

189 m

Tracy Saint Lawrence River Powerline Crossing

Canada

Tracy

174.6 m

tallest electricity pylon in Canada

Bosporus overhead line crossing III

1999

Turkey

Istanbul

160 m

Pylons of Cadiz

1955

Spain

Cadiz

158 m

Aust Severn Powerline Crossing

Aust

148.75 m

132kV Thames Crossing

1932

West Thurrock

148.4 m

demolished in 1987

Karmsundet Powerline Crossing

Norway

Karmsundet

143.5 m

Limfjorden Overhead powerline crossing 2

Denmark

Raerup

141.7 m

Saint Lawrence River HVDC Quebec-New England Overhead Powerline Crossing

1989

Canada

Deschambault-Grondines

140 m

dismantled in 1992

Pylons of Voerde

1926

Germany

Voerde

138 m

Khlbrand Powerline Crossing

Germany

Hamburg

138 m

Bremen-Farge Weser Powerline Crossing

Germany

Bremen

135 m

Pylons of Ghesm Crossing

1984

Iran

Strait of Ghesm

130 m

One pylon standing on a caisson in the sea

Shukhov tower on the Oka River

1929

Russia

Dzerzhinsk

128 m

Hyperboloid structure

Tarchomin-Lomianki Vistula Powerline Crossing

Poland

Tarchomin-Lomianki

127 m ( Tarchomin), 121 m ( Lomianki)

Skolwin-Inoujcie Odra Powerline Crossing

Poland

Skolwin-Inoujcie

126 m ( Skolwin), 125 m ( Inoujcie)

Enerhodar Dnipro Powerline Crossing 2

1984

Ukraine

Enerhodar

126 m

Pylons on caissons

Bosporus overhead line crossing I

1957

Turkey

Istanbul

Bosporus overhead line crossing II

1983

Turkey

Istanbul

Little Belt Overhead powerline crossing 2

Denmark

Middelfart

125.3 m + 119.2 m

Duisburg-Wanheim Powerline Rhine Crossing

Germany

Duisburg

122 m

Little Belt Overhead powerline crossing 1

Denmark

Middelfart

119.5 m + 113.1 m

Pylons of Duisburg-Rheinhausen

1926

Germany

Duisburg-Rheinhausen

118.8 m

Bullenhausen Elbe Powerline Crossing

Germany

Bullenhausen

117 m

Lubaniew-Bobrowniki Vistula Powerline Crossing

Poland

Lubaniew/Bobrowniki

117 m

Ostrwek-Tursko Vistula Powerline Crossing

Poland

Ostrwek/Tursko

115 m

Riga Hydroelectric Power Plant Crossing Pylon

1974

Latvia

Salaspils

112 m

Bremen-Industriehafen Weser Powerline Crossing

1972-1974 ( line for three phase AC)

Germany

Bremen

111 m

two parallel running powerlines, one used for three phase AC, the other for traction current. Highest pylons designed for single phase AC use.

Nowy Bgpom-Probostwo Dolne Vistula Powerline Crossing

Poland

Nowy Bgpom/Probostwo Dolne

111 m ( Probostwo Dolne), 109 m ( Nowy Bgpom)

Daugava Powerline Crossing

1975

Latvia

Riga

110 m

Regw Gob Vistula Powerline Crossing

Poland

Regw/Gob

108 m

Orsoy Rhine Crossing

Germany

Orsoy

105 m

Limfjorden Overhead powerline crossing 1

Denmark

Raerup

101.2 m

Enerhodar Dnipro Powerline Crossing 1

1977

Ukraine

Enerhodar

100 m

Pylons on caissons

Reisholz Rhine Powerline Crossing

1917

Germany

Dsseldorf

Under the legs of the pylon on the east shore of Rhine there runs the rail to nearby Holthausen substation

380kV-Ems-Overhead Powerline Crossing

Germany

Mark (south of Weener)

84 m

Pylon in the artificial lake of Santa Maria

1959

Switzerland

Lake of Santa Maria

75 m

Pylon in an artificial lake

Leaning pylon of Mingjian

Taiwan

Mingjian

Earthquake memorial

Aggersund Crossing of Cross-Skagerak

1977

Denmark

Aggersund

70 m

tallest pylons of an HVDC-line in Europe

Eyachtal Span

1992

Germany

Hfen

70 m

Longest span of Germany ( 1444 metres)

Carquinez Strait Powerline Crossing

1901

United States

Benicia

68 m + 20 m

World’s first powerline crossing of a larger waterway

Pylon 1 of powerline departing Reuter West Power Station

Germany

Berlin

66 m

Chimney-like pylon with lattice steel crossbars

Pylon 310 of powerline Innertkirchen-Littau-Mettlen

1990

Switzerland

Littau

59,5 m

Tallest pylon of prefabricated concrete

Anlage 2610, Mast 69

Germany

Bochum

47 m

Pylon of 220kV-powerline decorated with balls in Ruhr-Park mall.

Colossus of Eislingen

1980

Germany

Eislingen/Fils

47 m

Pylon standing over a little river

Source

France

Amnville les Thermes

34 m / 28 m

4 pylons forming an artwork

Huddersfield Narrow Canal Pylon

Stalybridge

Pylon standing over Huddersfield Narrow Canal, perhaps the only pylon whose legs can be passed under by boat

Gallery

Detail of the insulators (the vertical string of discs) and conductor vibration dampers (the weights attached directly to the conductors) on a 275,000 volt suspension tower near Thornbury, South Gloucestershire, England, United Kingdom

A tubular pylon, or muguet (lily) pylon, of an Hydro-Qubec Transnergie line. These pylons are more visually appealing than their regular counterparts. The tubular pylons are used in urban settings, such as this one in Gatineau, Quebec, Canada, for high-voltage lines, from 110 to 315 kV.

Pylon decorated with balls in Ruhr Park, Bochum, Germany

Pylon straddling the Huddersfield Narrow Canal in Stalybridge, West Yorkshire, United Kingdom

Antennas Installation

admin — Wed, 18 Aug 2010 18:36:52 +0000

Direct to home services are becoming popular by the day for television users. While most of us are aware of the advantages a DTH service offers, there is one particular point that serves as a disadvantage. The setting up of the receiving antenna needs to be done with absolute precision. Even a slight tilt in the angle of the antenna could lead to distorted signals & a poor picture quality.

The antenna install process is a complex one to perform. Various issues need to be taken care of before working on the actual installation. Signal levels differ from one place to another. Certain antennas don’t work if the signal strength lies beyond its reception level. Skilled technicians first test the signal strength at your residential or industrial premises. Highly skilled antenna installers then choose to install the antenna at an appropriate place based on the altitude and the available signal strength. Thereafter, the coaxial cable is connected from the dish to the receiver. For better antenna design, it is good to use the zip ties and screw clips for attaching the cable to the mast. After a successful installation, the quality of reception needs be tested thoroughly.

If you are experiencing problems with your existing antennas, professional technical help is needed to resolve these issues. These technicians will diagnose the problem thoroughly and suggest custom solutions to resolve the issue.

Hiring skilled technicians is highly recommended for all your antenna installation needs. Before choosing a professional company, people need to confirm their quality of service through the testimonials left behind by the existing customer base. The best antenna installation companies also offer a warranty for 3 to 5 years and strong customer support for their services. Most antenna specialists also offer additional services such as installation of data points and telephones, TVs and home theatres, setting up of internet access, repairing or installing data cable network and setting up or troubleshooting your home network.

Patrick Sherrin is a professional consultant involved in directing strategy and delivering marketing solutions for a large no. of online businesses in Australia.

How do Cell Phones Work

admin — Sun, 08 Aug 2010 05:01:40 +0000

Instant Cell Phone search lookup Get Name, Address. City & more www.Addresses.com/CellPhoneLookUp

We have become so addicted to cell phones, that it’s very difficult to imagine life without them. Whenever we do try to imagine, we end up convincing ourselves that it isn’t possible to survive without these technological marvels. In a study undertaken by the Institute for Social Research at the University of Michigan, 83 percent respondents agreed that cell phones had made life a lot easier for them. Although they have become an integral part of our life, not many of us are probably aware of how cell phones work. In fact, most of the people think that cell phone working principle is too complex for a layman to understand. Before we move on to how do cell phones work, let’s take a brief look at some of the basics of cell phones.

What is a Cell Phone?
The simplest possible definition of a cell phone is a two-way electronic device that uses radio frequencies in order to facilitate voice and data communication over the network. Alexander Graham Bell invented the telephone in 1876, while Nikola Tesla came up with the basics of radio in 1880s. Eventually, both these technologies were combined to come up with the gadget we refer to as the cell phone or mobile phone. Over a period of time, cell phones have undergone a drastic change from just being an upgraded variant of walkie-talkies, to a much more sophisticated multimedia device. Cell phones available today are not just restricted to voice or text conversation, but also accomplish a wide range of tasks, including music downloads and internet access. To know how mobile phones work, you can read more about how does a mobile phone work.

How do Cell Phones Work?
Even though modern cell phones are capable of doing much more than their conventional counterparts, their primary function still remains voice and data communication over the network. This is basically accomplished by the transmission of radio waves from one base station to another. When you attempt to call another cell phone from your phone, a signal is sent to the base station of the cell phone which you are attempting to call. A base station, also referred to as mast or antenna, is a wireless communications station set up at a particular geographical location. The geographical area covered by a single base station is known as a cell. When the signal reaches the base station, it is assigned a specific radio frequency channel in order to facilitate conversation between the two individuals without any sort of interference. After the signal is processed, it is sent to a call switching center. Here the call is transferred to another cell phone, either directly or through a local carrier. Although the entire process seems to be quite complex, it actually takes less than a minute to connect you to the cell phone you are calling.

From skyscrapers to wind turbines amp#039 use Rope Access

admin — Sat, 07 Aug 2010 14:43:57 +0000

With health & safety being one of the drivers of modern business, there is an increasing demand for regular structural inspection and early repair. Rope Access is leading the way, providing a safe and cost effective solution when dealing with tall structures.

When you add these tall and unusually shaped buildings to other structures such as onshore and offshore wind turbines, oil rigs, radio masts and bridges, it becomes clear that worldwide we have created a range of maintenance challenges.

Rope access can be the cost effective solution to these challenges. Rope access works by permanently attaching the technician to the building using two separate ropes anchored to two different points. This ensures the safety of the rope access technician and allows them to access any point on the structure. With the freedom of movement provided by the dual tethering technique it is easy to see how rope access allows work to be performed anywhere on a structure, even if that structure has a challenging shape.

As far as training goes, rope access technicians have generally undergone IRATA rope access training before taking up their jobs. IRATA is the global industry body for rope access workers. Key elements of IRATA training include team work and health & safety. This has resulted in an accident rate which is far lower than in comparable industries with only one fatality in the last decade.

Most rope access technicians have undergone IRATA rope access training before taking up their jobs. IRATA is the worldwide industry body for rope access workers. IRATA’s training follows strict rules and trainees have to pass written and practical exams before being certified at the basic level. Further qualifications require a minimum of a year’s high rope work plus further training and exams.

Key elements of IRATA training include team work and health & safety. This has resulted in an accident rate which is far lower than in comparable industries with only one fatality in the last two decades.

Whilst the list of applications for rope access is ever growing, rope access projects can mainly be divided into five broad areas. These are surveying, painting & cleaning, maintenance & repair, installation & engineering and geotechnical.

Surveying – The ability to regularly survey structures for potential risks is taking increasing priority in today’s health & safety conscious world. With the need for risk prevention solutions increasingly coming to the fore, rope access allows quick, thorough and safe building inspections. This can lead to early identification and repair of potential problems and therefore to reduced downtime and increased safety. Structural surveying using rope access techniques is used for a range of applications, including oil platforms, shipping, buildings, wind turbines and cliffs.

Painting and cleaning – Rope access techniques can be used to provide solutions as diverse as high rise window cleaning, bridge cleaning, and even statue cleaning. It is vital for structures which incorporate delicate equipment to be cleaned regularly to prevent a build up of dirt from damaging the mechanisms. Rope access also allows high rise painting to be carried out on a flexible schedule and with minimal disruption to normal operations

Maintenance & repair – is essential if you are to minimise disruption from faults. Because rope access technicians require no scaffolding or other bulky ground equipment, they are extremely cost effective. This means that you can undertake regular maintenance on tall structures. Rope access technicians can be quickly deployed so that any faults that develop can be quickly repaired, minimising disruption and increasing safety.

Installation & engineering – Rope access technicians tend to have other skills including electrical, engineering and technical. They are therefore invaluable in installing and maintaining equipment such as satellite dishes, microwave antennae and radio masts.

Geotechnical ‘ For both man made cliffs at the sides of roads or natural cliffs overlooking the sea, sooner or later the question of stability arises. Local Authorities have a duty of care to review and make recommendations on the stability of cliffs and steep drops. Rope access techniques are invaluable in both the review and in carrying out stabilising measures such as netting, spraying concrete, anchoring rocks or soil fixing.

Rope access work is extremely cost effective. Because there is no need for scaffolding, teams can be deployed quickly. Faults can therefore be corrected at an early stage and with minimal disruption. Not only will you save the cost of scaffolding, because of the way the technicians and tools are tethered man hours are reduced thus saving further costs. In addition the level of training required by IRATA means that the rope access contractors are highly skilled and this reduces accidents and increases speed.

So there you have it, rope access, the solution to working with all tall structures, whatever the architects dream up.

Whether you need a bridge painting or a wind turbine repaired Rope Access UK can help. Click here now for Rope Access .

Mobile phone

admin — Fri, 23 Jul 2010 11:08:04 +0000

History

Portable Cellphone 1970′s

Main article: History of mobile phones

Analog Motorola DynaTAC 8000X Advanced Mobile Phone System mobile phone as of 1983

In 1908, U.S. Patent 887,357 for a wireless telephone was issued to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to “cave radio” telephones and not directly to cellular telephony as the term is currently understood. Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to Reginald Fessenden’s invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held mobile radio devices have been available since 1973. A patent for the first wireless phone as we know today was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969.

In 1945, the zero generation (0G) of mobile telephones was introduced.[citation needed] Like other technologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole area while in use.

In 1960, the world first partly automatic car phone system Mobile System A (MTA)|MTA was launched in Sweden. With MTA, calls could be made and received in the car to/from the public telephone network, and the car phone could be paged. The phone number was dialed using a rotary dial. Calling from the car was fully automatic, while calling to it required an operator. The person who wanted to call a mobile phone had to know which base station the mobile phone was covered by. The system was developed by Sture Laurn and other engineers at Televerket network operator. Ericsson provided the switchboard while Svenska Radioaktiebolaget (SRA) owned by Ericsson and Marconi provided the telephones and base station equipment. MTA phones were consisted of vacuum tubes and relays, and had a weight of 40 kg. In 1962, a more modern version called Mobile System B (MTB) was launched, which was a push-button telephone, and which used transistors in order to enhance the telephone calling capacity and improve its operational reliability. In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success.

The concepts of frequency reuse and handoff, as well as a number of other concepts that formed the basis of modern cell phone technology, were described in the 1970s; see for example Fluhr and Nussbaum, Hachenburg et al. , and U.S. Patent 4,152,647, issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.

Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for hand-held use in a non-vehicle setting. Cooper is the first inventor named on “Radio telephone system” filed on October 17, 1973 with the US Patent Office and later issued as US Patent 3,906,166; other named contributors on the patent included Cooper’s boss, John F. Mitchell, Motorola’s chief of portable communication products, who successfully pushed Motorola to develop wireless communication products that would be small enough to use outside the home, office or automobile and participated in the design of the cellular phone. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone on April 3, 1973 to a rival, Dr. Joel S. Engel of Bell Labs.

Analog cellular telephony (1G)

Main article: 1G

The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT in 1979. The initial launch network covered the full metropolitan area of Tokyo’s over 20 million inhabitants with a cellular network of 23 base stations. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nation-wide 2G network.

The second launch of 1G networks was the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden in 1981.. NMT was the first mobile phone network featuring international roaming. The Swedish electrical engineer sten Mkitalo started to work on this vision in 1966, and is considered as the father of the NMT system and some consider him also the father of the cellular phone.

Personal Handy-phone System mobiles and modems used in Japan around 19972003

Several countries were among the earliest to launch 1G networks in the early 1980s including the UK, Mexico and Canada. The first 1G network launched in the USA was Chicago based Ameritech in 1983 using the famous first hand-held mobile phone Motorola DynaTAC. In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally controlled base stations (cell sites), each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system, a signal between a base station (cell site) and a terminal (phone) only need be strong enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells.

The first NMT installations as well as the First AMPS installations were based on the Ericsson AXE digital exchange nodes.

Cellular systems required several leaps of technology, including handover, which allowed a conversation to continue as a mobile phone traveled from cell to cell. This system included variable transmission power in both the base stations and the telephones (controlled by the base stations), which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expandednd cell sizes shrankhe antennae could be lowered on their original masts to reduce range.

A 1991 GSM mobile phone

Digital mobile communication (2G)

Main articles: 2G, 2.5G, and 2.75G

The first “modern” network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network.

The first data services appeared on mobile phones starting with person-to-person SMS text messaging in Finland in 1993. First trial payments using a mobile phone to pay for a Coca Cola vending machine were set in Finland in 1998. The first commercial payments were mobile parking trialled in Sweden but first commercially launched in Norway in 1999. The first commercial payment system to mimic banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Globe and Smart. The first content sold to mobile phones was the ringing tone, first launched in 1998 in Finland. The first full internet service on mobile phones was introduced by NTT DoCoMo in Japan in 1999.

Wideband mobile communication (3G)

Main article: 3G

In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard. The standard 2G CDMA networks became 3G compliant with the adoption of Revision A to EV-DO. Revision A of EV-DO makes several additions to the protocol while keeping it completely backwards compatible with older versions of EV-DO.

These changes included the introduction of several new forward link data rates that increase the maximum burst rate from 2.45 Mbit/s to 3.1 Mbit/s. Also included were protocols that would decrease connection establishment time (called enhanced access channel MAC), the ability for more than one mobile to share the same time slot (multi-user packets) and the introduction of QoS flags. All these were put in place to allow for low latency, low bit rate communications such as VoIP.

One of the newest 3G technologies to implemented is High-Speed Downlink Packet Access (HSDPA). It is an enhanced 3G (third generation) mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family, also coined 3.5G, 3G+ or turbo 3G, which allows networks based on Universal Mobile Telecommunications System (UMTS) to have higher data transfer speeds and capacity. Current HSDPA deployments support down-link speeds of 1.8, 3.6, 7.2 and 14.0 Mbit/s. Further speed increases are available with HSPA+, which provides speeds of up to 42 Mbit/s downlink and 84 Mbit/s with Release 9 of the 3GPP standards.

Broadband Fourth generation (4G)

Main article: 4G

The recently released 4th generation, also known as Beyond 3G, aims to provide broadband wireless access with nominal data rates of 100 Mbit/s to fast moving devices, and 1 Gbit/s to stationary devices defined by the ITU-R 4G systems may be based on the 3GPP LTE (Long Term Evolution) cellular standard, offering peak bit rates of 326.4 Mbit/s. It may perhaps also be based on WiMax or Flash-OFDM wireless metropolitan area network technologies that promise broadband wireless access with speeds that reaches 233 Mbit/s for mobile users. The radio interface in these systems is based on all-IP packet switching, MIMO diversity, multi-carrier modulation schemes, dynamic channel assignment (DCA) and channel-dependent scheduling. A 4G system should be a complete replacement for current network infrastructure and is expected to be able to provide a comprehensive and secure IP solution where voice, data, and streamed multimedia can be given to users on a “Anytime, Anywhere” basis, and at much higher data rates than previous generations. Sprint has a 4G network in select areas. By 2011 it is expected that more wireless companies will launch 4G Broadband networks.

Uses

Mobile phones are used for a variety of purposes, including keeping in touch with family members, conducting business, and having access to a telephone in the event of an emergency.

Organizations that aid victims of domestic violence may offer a cell phone to potential victims without the abuser’s knowledge. These devices are often old phones that are donated and refurbished to meet the victim’s emergency needs.

Child predators have taken advantage of cell phones to secretly communicate with children without the knowledge of their parents or teachers.

The advent of widespread text messaging has resulted in the cell phone novel; the first literary genre to emerge from the cellular age via text messaging to a website that collects the novels as a whole. Paul Levinson, in Information on the Move (2004), says “…nowadays, a writer can write just about as easily, anywhere, as a reader can read” and they are “not only personal but portable”.

Multiple phones

Individuals may have multiple cell phones for separate purposes, such as for business and personal use. Multiple phones (or multiple SIM cards) may be used to take advantage of the benefits of different calling plans particular plan might provide cheaper local calls, long-distance calls, international calls, or roaming. A study by Motorola found that one in ten cell phone subscribers have a second phone that often is kept secret from other family members. These phones may be used to engage in activities including extramarital affairs or clandestine business dealings.

Sharing

Cell phone sharing is a phenomenon which exists around the world. It is prevalent in urban India, as families and groups of friends often share one or more mobiles among their members. Two types of sharing which exist are “conspicuous” and “stealthy” sharing. An example of conspicuous sharing takes place when someone calls the friend of the person they are trying to reach in hopes of being able to talk to that individual; the latter type of sharing occurs when an individual uses another’s cell phone without their knowledge. Phone sharing does not only take place because of its economic benefits, but also often due to familial customs and traditional gender roles.

Another example of cell phone sharing occurs in Burkina Faso. There it is not uncommon for a village to only have access to one cell phone. This cell phone is typically owned by a person who is not natively from the village, such as a teacher or missionary. Although the cell phone is the sole property of one individual, it is the expectation that other members of the village are allowed to use the cell phone to make necessary calls. Although some may consider this a burden, it can actually be an opportunity to engage in reciprocal obligations. This type of cell phone sharing is an important for the small villages in Burkina Faso because it allows them to keep up with the expectations of the globalizing world.

Handsets

A Nokia phone with box.

A printed circuit board inside a mobile phone

There are several categories of mobile phones, from basic phones to feature phones such as musicphones and cameraphones. There are also smartphones, the first smartphone was the Nokia 9000 Communicator in 1996 which incorporated PDA functionality to the basic mobile phone at the time. As miniaturisation and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today. Several phone series have been introduced to address a given market segment, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia Nseries of multimedia phones, the Palm Pre the HTC Dream and the Apple iPhone.

Features

Main articles: Mobile phone features and Smartphone

Mobile phones often have beyond sending text messages and making voice calls, including call registers, GPS navigation, music (MP3) and video (MP4) playback, RDS radio receiver, alarms, memo and document recording, personal organiser and personal digital assistant functions, ability to watch streaming video or download video for later viewing, video calling, built-in cameras (1.0+ Mpx) and camcorders (video recording), with autofocus and flash, ringtones, games, PTT, memory card reader (SD), USB (2.0), infrared, Bluetooth (2.0) and WiFi connectivity, instant messaging, Internet e-mail and browsing and serving as a wireless modem for a PC, and soon will also serve as a console of sorts to online games and other high quality games. Some phones also include a touchscreen.

Nokia and the University of Cambridge are demonstrating a bendable cell phone called the Morph.

See also: Videophone, for UMTS-type mobile phones employing simultaneous video and audio

Software and applications

A phone with touchscreen feature.

Mobile phone subscribers per 100 inhabitants 19972007

The most commonly used data application on mobile phones is SMS text messaging, with 74% of all mobile phone users as active users (over 2.4 billion out of 3.3 billion total subscribers at the end of 2007). SMS text messaging was worth over 100 billion dollars in annual revenues in 2007 and the worldwide average of messaging use is 2.6 SMS sent per day per person across the whole mobile phone subscriber base (source Informa 2007). The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.

The other non-SMS data services used by mobile phones were worth 31 billion dollars in 2007, and were led by mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising (source: Informa 2007). The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringing tone service. In 1999 Japanese mobile operator NTT DoCoMo introduced its mobile internet service, i-Mode, which today is the world’s largest mobile internet service and roughly the same size as Google in annual revenues.

The first mobile news service, delivered via SMS, was launched in Finland in 2000. Mobile news services are expanding with many organisations providing “on-demand” news services by SMS. Some also provide “instant” news pushed out by SMS. Mobile telephony also facilitates activism and public journalism being explored by Reuters and Yahoo! and small independent news companies such as Jasmine News in Sri Lanka.

Companies are starting to offer mobile services such as job search and career advice. Consumer applications are on the rise and include everything from information guides on local activities and events to mobile coupons and discount offers one can use to save money on purchases. Even tools for creating websites for mobile phones are increasingly becoming available.

Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually the idea spread and in 1999 the Philippines launched the first commercial mobile payments systems, on the mobile operators Globe and Smart. Today mobile payments ranging from mobile banking to mobile credit cards to mobile commerce are very widely used in Asia and Africa, and in selected European markets. For example in the Philippines it is not unusual to have one’s entire paycheck paid to the mobile account. In Kenya the limit of money transfers from one mobile banking account to another is one million US dollars. In India paying utility bills with mobile gains a 5% discount. In Estonia mobile phones are the most popular method of paying for public parking.

Power supply

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Mobile phone charging service in Uganda

Mobile phones generally obtain power from rechargeable batteries. There are a variety of ways used to charge cell phones, including USB, portable batteries, mains power (using an AC adapter), cigarette lighters (using an adapter), or a dynamo. In 2009, wireless charging became a reality, and the first wireless charger was released for consumer use.

Standardization of Micro-USB connector for charging

Starting from 2010, many mobile phone manufacturers have agreed to use the Micro-USB connector for charging their phones. The mobile phone manufacturers who have agreed to this standard include:

Apple

LG

Motorola

Nokia

Research In Motion

Samsung

Sony Ericsson

On 17 February 2009, the GSM Association announced that they had agreed on a standard charger for mobile phones. The standard connector to be adopted by 17 manufacturers in the Open Mobile Terminal Platform including Nokia, Motorola and Samsung is to be the micro-USB connector (several media reports erroneously reported this as the mini-USB). The new chargers will be much more efficient than existing chargers. Having a standard charger for all phones, means that manufacturers will no longer have to supply a charger with every new phone.

In addition, on 22 October 2009 the International Telecommunication Union (ITU) announced that it had embraced micro-USB as the Universal Charger Solution its “energy-efficient one-charger-fits-all new mobile phone solution”, and added: “Based on the Micro-USB interface, UCS chargers will also include a 4-star or higher efficiency rating up to three times more energy-efficient than an unrated charger.”

Charger efficiency

The world’s five largest handset makers introduced a new rating system in November 2008 to help consumers more easily identify the most energy-efficient chargers

The majority of energy lost in a mobile phone charger is in its no load condition, when the mobile phone is not connected but the charger has been left plugged in and using power. To combat this in November 2008 the top five mobile phone manufacturers Nokia, Samsung, LG Electronics, Sony Ericsson and Motorola set up a star rating system to rate the efficiency of their chargers in the no-load condition. Starting at zero stars for >0.5 W and going up to the top five star rating for <0.03 W (30 mW) no load power.

A number of semiconductor companies offering flyback controllers, such as Power Integrations and CamSemi, now claim that the five star standard can be achieved with use of their product.

Battery

Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. lithium ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-polymer batteries as opposed to the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternative power sources, including solar cells and Coca Cola.

SIM card

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Main article: Subscriber Identity Module

Typical mobile phone SIM card

In addition to the battery, GSM mobile phones require a small microchip, called a Subscriber Identity Module or SIM Card, to function. Approximately the size of a small postage stamp, the SIM Card is usually placed underneath the battery in the rear of the unit, and (when properly activated) stores the phone’s configuration data, and information about the phone itself, such as which calling plan the subscriber is using. When the subscriber removes the SIM Card, it can be re-inserted into another phone that is configured to accept the SIM card and used as normal.

Each SIM Card is activated by use of a unique numerical identifier; once activated, the identifier is locked down and the card is permanently locked in to the activating network. For this reason, most retailers refuse to accept the return of an activated SIM Card.

Those cell phones that do not use a SIM Card have the data programmed in to their memory. This data is accessed by using a special digit sequence to access the “NAM” as in “Name” or number programming menu. From here, one can add information such as a new number for the phone, new Service Provider numbers, new emergency numbers, change their Authentication Key or A-Key code, and update their Preferred Roaming List or PRL. However, to prevent someone from accidentally disabling their phone or removing it from the network, the Service Provider puts a lock on this data called a Master Subsidiary Lock or MSL.

The MSL also ensures that the Service Provider gets payment for the phone that was purchased or “leased”. For example, the Motorola RAZR V9C costs upwards of CAD $500. Depending on the carrier, such a phone may be available for as little as $200. The difference is paid by the customer in the form of a monthly bill. If the carrier did not use an MSL, then they may lose the $300$400 difference that is paid in the monthly bill, since some customers would cancel their service and take the phone to another carrier.

The MSL applies to the SIM only so once the contract has been completed the MSL still applies to the SIM. The phone however, is also initially locked by the manufacturer into the Service Providers MSL. This lock may be disabled so that the phone can use other Service Providers SIM cards. Most phones purchased outside the US are unlocked phones because there are numerous Service Providers in close proximity to one another or have overlapping coverage. The cost to unlock a phone varies but is usually very cheap and is sometimes provided by independent phone vendors.

Having an unlocked phone is extremely useful for travelers due to the high cost of using the MSL Service Providers access when outside the normal coverage areas. It can cost sometimes up to 10 times as much to use a locked phone overseas as in the normal service area, even with discounted rates. T-Mobile will provide a SIM unlock code to account holders in good standing after 90 days according to their FAQ.

For example, in Jamaica, an AT&T subscriber might pay in excess of US$1.65 per minute for discounted international service while a B-Mobile (Jamaican) customer would pay US$0.20 per minute for the same international service. Some Service Providers focus sales on international sales while others focus on regional sales. For example, the same B-Mobile customer might pay more for local calls but less for international calls than a subscriber to the Jamaican national phone C&W (Cable & Wireless) company. These rate differences are mainly due to currency variations because SIM purchases are made in the local currency. In the US, this type of service competition does not exist because some of the major Service Providers do not offer Pay-As-You-Go services. [Needs Pay-As-You-Go references, rumored T-Mobile, Verizon provide one, AT&T does not as of 12/2008]

Market

Mobile phone manufacturers’ market share in Q3/2008

The world’s largest individual mobile operator is China Mobile with over 500 million mobile phone subcribers. The world’s largest mobile operator group by subscribers is UK based Vodafone. There are over 600 mobile operators and carriers in commercial production worldwide. Over 50 mobile operators have over 10 million subscribers each, and over 150 mobile operators have at least one million subscribers by the end of 2008 (source wireless intelligence).

In mobile phone handsets, in Q3/2008, Nokia was the world’s largest manufacturer of mobile phones, with a global device market share of 39.4%, followed by Samsung (17.3%), Sony Ericsson (8.6%), Motorola (8.5%) and LG Electronics (7.7%). These manufacturers accounted for over 80% of all mobile phones sold at that time.

Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQ-Siemens, CECT, HTC Corporation, Fujitsu, Kyocera, Mitsubishi Electric, NEC, Neonode, Panasonic, Palm, Matsushita, Pantech Wireless Inc., Philips, Qualcomm Inc., Research In Motion Ltd. (RIM), Sagem, Sanyo, Sharp, Siemens, Sendo, Sierra Wireless, SK Teletech, T&A Alcatel, Huawei, Trium, Toshiba[citation needed] and Vidalco. There are also specialist communication systems related to (but distinct from) mobile phones.

Media

The mobile phone became a mass media channel in 1998 when the first ringtones were sold to mobile phones by Radiolinja in Finland. Soon other media content appeared such as news, videogames, jokes, horoscopes, TV content and advertising. In 2006 the total value of mobile phone paid media content exceeded internet paid media content and was worth 31 Billion dollars (source Informa 2007). The value of music on phones was worth 9.3 Billion dollars in 2007 and gaming was worth over 5 billion dollars in 2007.

The mobile phone is often called the Fourth Screen (if counting cinema, TV and PC screens as the first three) or Third Screen (counting only TV and PC screens).[weasel words] It is also called the Seventh of the Mass Media (with Print, Recordings, Cinema, Radio, TV and Internet the first six). Most early content for mobile tended to be copies of legacy media, such as the banner advertisement or the TV news highlight video clip. Recently unique content for mobile has been emerging, from the ringing tones and ringback tones in music to “mobisodes,” video content that has been produced exclusively for mobile phones.

The advent of media on the mobile phone has also produced the opportunity to identify and track Alpha Users or Hubs, the most influential members of any social community. AMF Ventures measured in 2007 the relative accuracy of three mass media, and found that audience measures on mobile were nine times more accurate than on the internet and 90 times more accurate than on TV.[original research?]

Privacy

Cell phones have numerous privacy issues associated with them, and are regularly used by governments to perform surveillance.

Law enforcement and intelligence services in the UK and the US possess technology to remotely activate the microphones in cell phones in order to listen to conversations that take place nearby the person who holds the phone.

Mobile phones are also commonly used to collect location data. The geographical location of a mobile phone can be determined easily (whether it is being used or not), using a technique known multilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phone.

Restriction on usage

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There exists a growing body within the scientific community which believes mobile phone use represents a long-term health risk, particularly to young children. Certain countries, including France, restrict the use and sale of cell phones to minors for this reason. The telecommunications insdustry rejects such claims, claming there is no proof of long-term adverse health effects. Groups of scientists, however, such as the U.S. – based group “Bioinitiative (see www.bioinitiative.org) argue that because mobile phone use is recently-introduced technology, long-term ‘proof’ has been impossible – and use should be restricted, or monitored closely, while the technology is still new. The very first generation of cell-phone users, for example, are only now entering middle-age. Studies in Europe, for example, are only now emerging which link long-term cell phone use to brain tumours. Other studies link cell-phone use to child-diabetes, concentration difficulty, and sleep disorders.

Use while driving

Main article: Mobile phones and driving safety

Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accident. Because of this, many jurisdictions prohibit the use of mobile phones while driving. Egypt, Israel, Japan, Portugal and Singapore ban both hand-held and hands-free use of a mobile phone whilst many other countries ncluding the UK, France, and many US states ban hand-held phone use only, allowing hands-free use.

Due to the increasing complexity of mobile phones ften more like mobile computers in their available uses it has introduced additional difficulties for law enforcement officials in being able to tell one usage from another as drivers use their devices. This is more apparent in those countries who ban both hand-held and hands-free usage, rather those who have banned hand-held use only, as officials cannot easily tell which function of the mobile phone is being used simply by visually looking at the driver. This can mean that drivers may be stopped for using their device illegally on a phone call, when in fact they were not; instead using the device for a legal purpose such as the phones’ incorporated controls for car stereo or satnav usage either as part of the cars’ own device or directly on the mobile phone itself.

Cases like these can often only be proved otherwise by a check of the mobile operators phone call records to see if a call was taking place during the journey concerned. Although in many countries the law enforcement official may have stopped the driver for a differing offence, for example, for lack of due care and attention in relation to their driving.

Schools

Some schools limit or restrict the use of mobile phones. Schools set restrictions on the use of mobile phones because of the use of cell phones for cheating on tests, harassment and bullying, causing threats to the schools security, distractions to the students and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities, public restrooms and swimming pools due to the built-in cameras that most phones now feature, though some countries and manufacturers have taken steps to protect privacy in such areas by giving their products audible ‘shutter noises’, that cannot be disabled.[citation needed]

A recently published study has reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.
Comparison to similar systems

Car phone

A type of telephone permanently mounted in a vehicle, these often have more powerful transmitters, an external antenna and loudspeaker for hands free use. They usually connect to the same networks as regular mobile phones.

Cordless telephone (portable phone)

Cordless phones are telephones which use one or more radio handsets in place of a wired handset. The handsets connect wirelessly to a base station, which in turn connects to a conventional land line for calling. Unlike mobile phones, cordless phones use private base stations (belonging to the land-line subscriber), which are not shared.

Professional Mobile Radio

Advanced professional mobile radio systems can be very similar to mobile phone systems. Notably, the IDEN standard has been used as both a private trunked radio system as well as the technology for several large public providers. Similar attempts have even been made to use TETRA, the European digital PMR standard, to implement public mobile networks.

Radio phone

This is a term which covers radios which could connect into the telephone network. These phones may not be mobile; for example, they may require a mains power supply, or they may require the assistance of a human operator to set up a PSTN phone call.

Satellite phone

This type of phone communicates directly with an artificial satellite, which in turn relays calls to a base station or another satellite phone. A single satellite can provide coverage to a much greater area than terrestrial base stations. Since satellite phones are costly, their use is typically limited to people in remote areas where no mobile phone coverage exists, such as mountain climbers, mariners in the open sea, and news reporters at disaster sites.

IP Phone

This type of phone delivers or receives calls over internet, LAN or WAN networks using VoIP as opposed to traditional CDMA and GSM networks. In business, the majority of these IP Phones tend to be connected via wired Ethernet, however wireless varieties do exist. Several vendors have developed standalone WiFi phones. Additionally, some cellular mobile phones include the ability to place VoIP calls over cellular high speed data networks and/or wireless internet.

See also

Mobile phone radiation and health

Customer proprietary network information

Flexible keyboard

Rotary dial

Push-button telephone

Harvard sentences

Information and communication technologies for development

List of countries by number of mobile phones in use

Mobile internet device (MID)

Personal Handy-phone System

smartphone

Pay As You Go (phone)

SIM card

Mobile broadband

Tethering

PDA

Netbook

laptop

References

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^ Mingtao Shi, Technology base of mobile cellular operators in Germany and China, page 55

^ Facts about the Mobile. A Journey through Time

^ “Switching Plan for a Cellular Mobile Telephone System:, Z. Fluhr and E. Nussbaum, IEEE Transactions on Communications volume 21, #11 p. 1281 (1973)

^ “Data signaling functions for a cellular mobile telephone system”, V. Hachenburg, B. Holm and J. Smith, IEEE Trans Vehicular Technology, volume 26, #1 p. 82 (1977)

^ Cooper, et al., “Radio Telephone System”, US Patent number 3,906,166; Filing date: Oct 17, 1973; Issue date: September 1975; Assignee Motorola

^ “Motorola Executive Helped spur Cellphone Revolution, Oversaw Ill-fated Iridium Project”. The Wall Street Journal, June 2021, 2009, p. A10.

^ “John F. Mitchell, 1928-2009: Was president of Motorola from 1980 to ’95, Chicago Tribune, June 17, 2009, retrieved June 17, 2009″. Chicagotribune.com. http://www.chicagotribune.com/news/chi-hed-jmitchell-17-jun17,0,955426.story. Retrieved 2009-07-29.

^ Shiels, Maggie (2003-04-21). [http://news.bbc.co.uk/1/hi/uk/2963619.stm "BBC interview with Martin CooperCell phones or cellular phones are so called as they cover compartmentalized, cell like areas. The origin of the Cell phone can be traced back to the year 1973 when Motorola came up with World`s first cellular portable telephone which was commercialised as Motorola DynaTAC 8000X. These days, new cell phones are being added at a rapid pace. The parts of them typically consist of following: circuit board; antenna; keyboard; LCD - liquid crystal display; battery; microphone; speaker. In recent times, they are available with a wide range of functions. To list a few functions, depending on the type of cell phone you choose: store contact information; keep track of appointments; set reminders; prepare to-do lists; send/receive e-mail; play games; send text messages (sms); access to internet; watch and enjoy TV; built-in calculator; integration with other devices like GPS receivers, MP3 players, etc. Cell phones, operating on radio frequency, have come up with an innovative cellular approach to counter limited availability of RF spectrum. Now, several cell phone towers are used to cater to a large geographic area. Each tower (base station), covers a circular area called a cell. A large region is split into a number of cells allowing different base stations to use the same channels/frequencies for communication. This enables thousands and thousands of mobile telephone users to share far fewer channels."]. BBC News. http://news.bbc.co.uk/1/hi/uk/2963619.stm. Retrieved 2009-07-29.

^ “Swedish National Museum of Science and Technology”. Tekniskamuseet.se. http://www.tekniskamuseet.se/mobilen/engelska/1980_90.shtml. Retrieved 2009-07-29.

^ Mobile and technology: The Basics of Mobile Phones

^ The cell phone 50 years – facts and numbers

^ UMTS World. “History of UMTS and 3G development”. Umtsworld.com. http://www.umtsworld.com/umts/history.htm. Retrieved 2009-07-29.

^ Gopal, Thawatt (11-15 March 2007). “EVDO Rev. A Control Channel Bandwidth Analysis for Paging”. IEEE Wireless Communications and Networking Conference. IEEE. pp. 32627. doi:10.1109/WCNC.2007.601.

^ a b Young Kyun, Kim; Prasad, Ramjee (2006). 4G Roadmap and Emerging Communication Technologies. Artech House 2006. pp. 1213. ISBN 1-58053-931-9.

^ By RICHARD BROOKSThe Press-Enterprise (2007-08-13). “Donated cell phones help battered women | San Bernardino County | PE.com | Southern California News | News for Inland Southern California”. PE.com. http://www.pe.com/localnews/sbcounty/stories/PE_News_Local_S_helpphones13.3d74734.html. Retrieved 2009-11-04.

^ By Christy Oglesby CNN (2008-01-11). “Cells, texting give predators secret path to kids”. CNN.com. http://www.cnn.com/2008/CRIME/01/11/teachers.charged/index.html. Retrieved 2009-11-04.

^ Goodyear, Dana (2009-01-07). “Letter from Japan: I Novels”. The New Yorker. http://www.newyorker.com/reporting/2008/12/22/081222fa_fact_goodyear. Retrieved 2009-07-29.

^ “UK | Millions keep secret mobile”. BBC News. 2001-10-16. http://news.bbc.co.uk/2/hi/uk_news/1602044.stm. Retrieved 2009-11-04.

^ Donner, Jonathan, and Steenson, Molly Wright. “Beyond the Personal and Private: Modes of Mobile Phone Sharing in Urban India.” In The Reconstruction of Space and Time: Mobile Communication Practices, edited by Scott Campbell and Rich Ling, 231-250. Piscatawy, NJ: Transaction Publishers, 2008.

^ Hahn, Hans and Kibora, Ludovic. “The Domestication of the Mobile Phone: Oral Society and New ICT in Burkina Faso”. Journal of Modern African Studes 46 (2008): 87-109.

^ Reardon, Marguerite. “Nokia demos bendable cell phone”. CNET News, February 25, 2008. Retrieved 20 July 2009.

^ “You Witness News”. News.yahoo.com. 2009-01-26. http://news.yahoo.com/you-witness-news. Retrieved 2009-07-29.

^ goingcellular.com Powermat wireless charger now available

^ EUROPA – Press Releases – Harmonisation of a charging capability of common charger for mobile phones

^ “GSM World agreement on Mobile phone Standard Charger”. http://www.gsmworld.com/newsroom/press-releases/2009/2548.htm.

^ pressinfo (2009-10-22). “Press Release: Universal phone charger standard approved One-size-fits-all solution will dramatically cut waste and GHG emissions”. Itu.int. http://www.itu.int/newsroom/press_releases/2009/49.html. Retrieved 2009-11-04.

^ Daily Mail

^ “Swapping SIM cards”. reviews.cnet.com. 2006-08-08. http://reviews.cnet.com/4520-3504_7-6625604-1.html. Retrieved 2009-09-04.

^ “By the Numbers: Top Five Mobile Phone Vendors in the Third Quarter of 2008 – RCR Wireless News”. Rcrwireless.com. 2009-07-21. http://www.rcrwireless.com/article/20081030/WIRELESS/810309997/. Retrieved 2009-07-29.

^ “Downloads_Guide”. Netsize. http://www.netsize.com/Ressources_Guide.htm. Retrieved 2009-07-29.

^ McCullagh, Declan; Anne Broache (December 1, 2006). “FBI taps cell phone mic as eavesdropping tool”. CNet News. http://news.cnet.com/FBI-taps-cell-phone-mic-as-eavesdropping-tool/2100-1029_3-6140191.html. Retrieved 2009-03-14.

^ Odell, Mark (August 1, 2005). “Use of mobile helped police keep tabs on suspect”. Financial Times. http://news.ft.com/cms/s/7166b8a2-02cb-11da-84e5-00000e2511c8.html. Retrieved 2009-03-14.

^ “Tracking a suspect by mobile phone”. BBC News. August 3, 2005. http://news.bbc.co.uk/1/hi/technology/4738219.stm. Retrieved 2009-03-14.

^ Miller, Joshua (March 14, 2009). “Cell Phone Tracking Can Locate Terrorists But Only Where It’s Legal”. FOX News. http://www.foxnews.com/story/0,2933,509211,00.html. Retrieved 2009-03-14.

^ de Waard, D., Schepers, P., Ormel, W. and Brookhuis, K., 2010, Mobile phone use while cycling: Incidence and effects on behaviour and safety, Ergonomics, Vol 53, No. 1, January 2010, pp 30 – 42.

^ “VoIP Support in Nokia Devices”. http://www.forum.nokia.com/Technology_Topics/Mobile_Technologies/VoIP/Nokia_VoIP_Framework/VoIP_support_in_Nokia_devices.xhtml. Retrieved 2009-08-16.

Further reading

Agar, Jon, Constant Touch: A Global History of the Mobile Phone, 2004 ISBN 1840465417

Ahonen, Tomi, m-Profits: Making Money with 3G Services, 2002, ISBN 0-470-84775-1

Ahonen, Kasper and Melkko, 3G Marketing 2004, ISBN 0-470-85100-7

Fessenden, R. A. (1908). “Wireless Telephony”. Annual Report of The Board Of Regents Of The Smithsonian Institution: 161196. http://books.google.com/books?id=gtQWAAAAYAAJ&pg=PA161. Retrieved 2009-08-07.

Glotz, Peter & Bertsch, Stefan, eds. Thumb Culture: The Meaning of Mobile Phones for Society, 2005

Katz, James E. & Aakhus, Mark, eds. Perpetual Contact: Mobile Communication, Private Talk, Public Performance, 2002

Kavoori, Anandam & Arceneaux, Noah, eds. The Cell Phone Reader: Essays in Social Transformation, 2006

Kopomaa, Timo. The City in Your Pocket, Gaudeamus 2000

Levinson, Paul, Cellphone: The Story of the World’s Most Mobile Medium, and How It Has Transformed Everything!, 2004 ISBN 1-4039-6041-0

Ling, Rich, The Mobile Connection: the Cell Phone’s Impact on Society, 2004 ISBN 1558609369

Ling, Rich and Pedersen, Per, eds. Mobile Communications: Re-negotiation of the Social Sphere, 2005 ISBN 1852339314

Home page of Rich Ling
Nyri, Kristf, ed. Mobile Communication: Essays on Cognition and Community, 2003

Nyri, Kristf, ed. Mobile Learning: Essays on Philosophy, Psychology and Education, 2003

Nyri, Kristf, ed. Mobile Democracy: Essays on Society, Self and Politics, 2003

Nyri, Kristf, ed. A Sense of Place: The Global and the Local in Mobile Communication, 2005

Nyri, Kristf, ed. Mobile Understanding: The Epistemology of Ubiquitous Communication, 2006

Plant, Dr. Sadie, on the mobile the effects of mobile telephones on social and individual life, 2001

Rheingold, Howard, Smart Mobs: The Next Social Revolution, 2002 ISBN 0738208612

Singh, Rohit (April 2009). Mobile phones for development and profit: a win-win scenario. Overseas Development Institute. p. 2. http://www.odi.org.uk/resources/odi-publications/opinions/128-mobile-phones-business-development-private-sector.pdf.

External links

Look up mobile phone in Wiktionary, the free dictionary.

Wikimedia Commons has media related to: Mobile phones

How Cell Phones Work at HowStuffWorks

Number of Mobile Subscribers by Country and per 100 people interactive world map.

Cell Phone, the ring heard around the world video documentary by the Canadian Broadcasting Corporation

“The Long Odyssey of the Cell Phone”, 15 photos with captions from Time magazine

Mobile Phone Buying Guide

http://www.worldtimezone.com/gsm.html

http://www.itu.int/dms_pub/itu-t/opb/sp/T-SP-E.164D-2009-PDF-E.pdf

http://www.itu.int/publ/T-SP-E.164C-2008/en

http://www.gsmworld.com/roaming/gsminfo/

v d e

Mobile phones

General

History GSM Development Features OS

Networking

Network operators Standard comparison Frequencies Mobile VoIP SIM WAP XHTML-MP Mobile phone signal

Generations: 0G 1G 2G 3G 4G

Devices

Manufacturers Camera phone Smartphones Form factors

Applications and services

Banking Blogging Commerce Content Email Gambling Gaming Health Instant messaging Learning Location tracking Marketing Music News Payment Publishing Search Text messaging SMS MMS Telephony Ticketing Web

Culture

Charms Comics Dating Novels Ringtones Phantom rings Japanese mobile phone culture

Health and environment

Electronic waste Radiation and health Blackberry thumb

Law

Driving Legality of recording by civilians Photography and the law Texting while driving

v d e

Mobile telephony and mobile telecommunications standards

0G (radio telephones)

MTS MTA MTB MTC IMTS MTD AMTS OLT Autoradiopuhelin

1G

NMT AMPS Hicap Mobitex DataTAC TACS ETACS

2G

GSM/3GPP family

GSM CSD

3GPP2 family

CdmaOne (IS-95)

Other

D-AMPS (IS-54 and IS-136) CDPD iDEN PDC PHS

2G transitional

GSM/3GPP family

HSCSD GPRS EDGE/EGPRS

3GPP2 family

CDMA2000 1xRTT (IS-2000)

iDEN family

WiDEN

3G (IMT-2000)

3GPP family

UMTS (UTRAN) WCDMA-FDD WCDMA-TDD UTRA-TDD LCR (TD-SCDMA)

3GPP2 family

CDMA2000 1xEV-DO (IS-856)

3G transitional

3GPP family

HSDPA HSUPA HSPA+ LTE (E-UTRA)

3GPP2 family

EV-DO Rev. A EV-DO Rev. B

Other

Mobile WiMAX (IEEE 802.16e-2005) Flash-OFDM IEEE 802.20

4G (IMT-Advanced)

3GPP family

LTE Advanced

WiMAX family

IEEE 802.16m

Related articles

History Comparison of standards List of standards Spectral efficiency comparison table Cellular frequencies Cellular network theory Mobile broadband

Categories: Embedded systems | Mobile telecommunications | Mobile telecommunication services | Mobile phonesHidden categories: Wikipedia semi-protected pages | Articles needing additional references from July 2009 | All articles needing additional references | All articles with unsourced statements | Articles with unsourced statements from November 2009 | Articles needing additional references from September 2009 | Articles with unsourced statements from March 2009 | All articles with specifically-marked weasel-worded phrases | Articles with specifically-marked weasel-worded phrases from July 2009 | All articles that may contain original research | Articles that may contain original research from August 2009 | Articles needing additional references from January 2010 | Articles with unsourced statements from July 2009

I am an expert from China Quality Lighting, usually analyzes all kind of industries situation, such as paint pump sprayer , aeg power tool.

Prepairing your yacht or boat for transport overland or international shipping

admin — Sun, 18 Jul 2010 02:36:21 +0000

Take the time to plan for your boat move.

Proper preparation of your boat for transport requires careful planning and attention to detail on both the part of the owner and the boat transport service companies involved. Proper preparation of the boat for transport is the responsibility of the owner.

Boat Transport companies do not typically prepare boats for transport. Marinas and boat yards personnel prepare boats and yachts for transport and typically will only allow their employees to prepare boats while on their property.

Communicate with your Boat Transportation Company. These boat transporting companies are grateful for…

Having the boat ready to load when the truck arrives at its scheduled time. Besides having to pay the driver for unnecessary delay, this also causes the boat transporting company to get behind on the other boats they have scheduled for transport. Transport companies do their best to deliver the boat at the estimated time. However, this is an approximation only due to the many factors beyond their control such as weather, traffic, permitted re-routes, and availability of marina operations for loading and offloading schedules.

Your consideration that if your boat is being moved at 60 miles per hour into a 14 mile per hour head wind, it is experiencing hurricane force conditions, as well as any inclement weather that may be encountered en-route. Please expect normal road dirt on the boat

Properly Measure Your Boat for Transport

When requesting a quote to transport your boat, the dimensions are extremely important. Please follow these guidelines for measuring your boat accurately. In order to transport your boat for the lowest possible price, boat transporters try to carry more than one small boat going in the same general direction at the same time. That is why it is important for the boat transporter to know the full overall length of your vessel in order to know what boats will fit on the trailers.

OVERALL LENGTH: Include bow pulpits, swim platforms, outboard motor brackets, outboard motors themselves (the length of the motors or out drives in the raised position). If on a trailer, include from the tip of the tongue to the end of the motor.

OVERALL HEIGHT: The maximum height of many overpasses is 13 feet 6 inches. Many oversized yachts require wide-belly low-boy trailers in order for the keel to set down low. Using these type trailers for tall yachts can sometimes be low enough to avoid using a pole car if the boat loaded is less than the state-by-state height restraint (the New England area has many low bridges and re-routes may be dictated by the Department of Transportation. Boats with an overall height greater than 13.6′ loaded on the trailer require special handling and routing. It is critical to measure from the bottom of the keel to the highest non-removable part of the boat.

The draft (from the waterline to the bottom of the keel) + clearance (from the waterline to the highest part of the vessel) equal the total standing height. Pending on your model, if the fly or command bridge may need to be removed. It is important to measure the vessel without the bridge and also provide bridge dimensions to ensure appropriate transport space. Remember measure twice – cut once!!!

The bridge should be placed somewhere suitable on the boat and make certain it is safely secured. If it must be placed on the trailer, a frame should be prepared for it to rest upon. If your radar arch is removed, it should be secured against your boat. You might consider using carpet to protect areas where surfaces may “touch”.

Electronics such as radios, Loran Systems, etc., should be shipped separately or securely stowed in your cabin, with all cabin doors, windows, and any other access, locked.

OVERALL BEAM/WIDTH: The beam of your boat is the measured as the widest point of the boat including anything attached to the boat.

Remove and properly store the following items. WHEN IN DOUBT…PULL IT OUT!!!

This includes valuables, all exterior electronics, Anchors, Antennas, Propellers, Flagstaffs, Outriggers, any item that extends beyond the stated length, width or height of your vessel, all canvas, screens, cushions, and weatherboards, radar transmitters, hailers, and dinghies.

Check the drain plugs. There should not be any water in the bilge while it is being transported.

Drain fuel and water tanks as much as possible. Be sure the tank is no more than ¼ full. During winter months, water should be drained from water systems, pumps, and air conditioners.

The batteries should be disconnected and the cables tied off to prevent contact.

If engine hatch covers are battery operated, they should be secured to prevent their opening while in transit.

Check for any loose items or items that could become loose

Additional instructions for transporting your wood boat.

It is highly recommended that wood boats be transported on their own custom cradle. This is suggested because there may be inherent structural weaknesses that are not readily visible or detectable. A well designed cradle will spread the weight of the boat over a much wider contact area. Wooden boats can be expected to dry out. A coat of linseed oil will help. Most boat transport companies will ask you to sign a release of liability for wood boats.

Additional Instructions for Sail Boat Transporting.

Make certain that all Mast Poles are un-stepped and de-rigged. All cables and spreaders should be bound to the pole. ALL rigging, winches, wind indicators, and lights must be removed from the mast. The strongest side of the mast should be left on our trailer. Wrapping of poles is optional, but should be considered. Carpet should be provided for the mast at the points of tie down. Expect some chafing at these points. If the mast is painted, it is almost impossible to keep the paint from chafing. The carrier will not pay to repaint masts if chafing occurs. Do not secure the mast to the boat, as there is a space on the carrier’s trailer for the mast. Should the mast be secured to the boat, the carrier will not be responsible for any resulting damage to the mast or the boat.

Life lines, stanchions, bow and stern pulpits should be removed if they render the boat over height. On center board sailboats, make sure the board is secured and will stay up in transit. Keel sailboats may expect some separation where the keel joins the hull. This is not structural damage, but rather is the paint or filler cracking at the joint. Light built or racing sailboats can expect some hull indentation from the support pads. These indentations generally disappear when the boat is returned to the water.

Rudders, sticks, ladders, outboards, and anything else that can turn or flap in the wind, should be removed and/or well secured.

Now that you have an idea of how to prep your boat for transporting internationally or demoestic stop by our website at http://www.yachtexports.com and lets us take it from there.

Justin Linder is part of the Yacht Export Group. Check us out at http://www.yachtexports.com

2009 Toyota Corolla Review a Review of the 2009 Toyota Corolla Automobile

admin — Mon, 12 Jul 2010 12:12:12 +0000

The 2009 Toyota Corolla is both innovative and reliable, with several new options that allow for safety and convenience. Impressive new features on the Corolla include a DVD navigation system with speakers to make trips more enjoyable, and also, the available Vehicle Stability Control, to allow for better control in adverse conditions. Combined with the Corolla’s traction control, these features make the Corolla ride a safe one.

The 2009 Corolla offers several standard safety features, including anti-lock brakes with brake assist and rear disk brakes. Its novel tilt and telescoping steering wheel make for an adventurous ride.

An integrated rear in-glass antenna adds to the Corolla’s novel look, while an acoustic noise-reducing windshield adds convenience to the model.

Interior comfort is provided with the Corolla’s standard air conditioning, near-flat rear floor and sliding center console. An enhanced design from previous model years provides the same amount of room, but has enhanced usability and storage. The model includes, for entertainment, the available JBL 6-disc in-dash CD changer with satellite radio capability. Bluetooth capability, an auxiliary audio jack and electronic power steering also are available.

Features such as independently illuminating map lights for the driver and front passenger show that the Corolla has advanced in its technology from previous years.

The Corolla, offering the same reliability, now comes with a new body style and increased interior and luggage room. The Corolla’s torque also is up with a 132-horse power, 1.8-liter dual engine keeps the Corolla riding fast, while in style.

Toyota’s 2009 all-new Corolla is a vehicle that combines technology, safety and affordability, making it a tough car to pass up when shopping for a new ride in the coming year.

Be sure to visit the Car Forum at http://www.TheAutomobileForum.com today! We hope that you enjoyed this 2009 Toyota Corolla review!

Radio Astronomy Centre

admin — Sun, 11 Jul 2010 23:07:32 +0000

Radio Astronomy Centre

Tata Institute of Fundamental Research

Ooty

CONTENTS

Introduction
Construction
Electronic systems
Electrical systems
Protection systems
Data acquisition system

INTRODUCTION

The Radio Astronomy

Radio astronomy is the study of universe with the help of radio waves emitted by celestial objects. Radio waves are mostly coming from highly energetic charged particles moving with velocities close to that of light in presence of magnetic fields with the help of directional antenna or telescope the strength of radio waves received from different directions from sky can be determined and a map of the radio signals from the sky can be made.

Radio Astronomy Centre at Ooty

The radio astronomy is one of the research institutes under Tata Institute of Fundamental Research(TIFR) proposed the hail tool of radio astronomy. A large structure radio telescope was designed in July 1963. A suitable site was

Selected in Nilgiri hills. The work that started in 1965 was completed by 1969. the co-ordinate latitude:11 22′ and co-ordinate longitude:-76 40′.

Ooty Radio Telescope (ORT)

ORT is located on the hill slopes close to muthorai village in Ooty. The unique feature of telescope is that it is stepped in the north to south direction down a natural hill slope of about 11 equal to the ideal latitude of the observatory. This arrangement ensures the axis of the telescope is parallel to the earth axis. This enables the ORT to track celestial objects for about 9.5hours by simply rotating the telescope mechanically in east to west direction.

CONSTRUCTION

The following are the building blocks of ORT:

Reflector
Dipole feed
Receiver

Reflector

The antenna reflector of ORT is the parabolic cylinder with its surface formed by 1100 stainless steel wires. Each fine stainless steel wire is of .38mm in diameter. These stainless steel wires are stretched along the length of cylinder.

Dipole Feed

The dipole feed consists of 1056 half wave dipoles hacked by a corner reflector and placed along the focal line on feed tracks. The physical aperture of antenna is 530 m long and 30 m wide.

Receiver

The local oscillator signal at 296.5 Mhz is generated in the receiver room that is located near adjacent to the telescopic antenna. The signal is carried in the transmission line to a central part where it branches into two parts. One branch is for the northern element modules and the other for the southern element modules. The RF amplifier is followed by a mixer which down converts the RF band to an intermediate frequency(IF) band centred at 30 Mhz. the IF signal from each module is transmitted to the receiver room through a separate coaxial cable.

ELECTRONIC SYSTEMS

Low Noise Amplifier(LNA)

The LNA, which comes immediately after the dipole, plays major role in determining the system temperature, and thus the overall sensitivity of the telescope. It should have a lowest noise figure at the frequency of operation with a noise figure of .06 db at 2 Ghz was chosen for LNA.

GaAs FET devices are generally used at microwave frequencies for optimum gain and low noise performance using high gain, high frequency gas FET at VHF and UHF frequencies however possess special problems.

A simple technique broadband loading of FET drain, was used to ensure stability over the wideband.

Phase shifters

Scanning the beam of a radio telescope consists of an array of antennas electronically switchable phase shifters employing PIN diodes are commonly used.

Types of phase shifters:

Phase lead-lag type
Micro strip line type

The second type is used in ORT. The characteristic impedance is 50 ohm. Here extra loss of .1 db and .05 db are provided in the direct path.

Image rejection filters

It is basically a band reject filter. The o/p of 326.5 Mhz from RF amplifier is fed to this filter. The o/p is obtained is in the band region of 15 Mhz.

Mixer

The mixer is generally an adder or subtractor circuit. The o/p’s from IRF and local oscillator phase shifter to produce the sum and difference o/p of the two frequencies.

Intermediate Frequency amplifier

It is a tuned amplifier tuned to 30 Mhz and bandwidth is limited to 4 Mhz to avoid unwanted signals. The receiver gain around 100 db. The receiver system is known as Super-heterodyne receiver.

ELECTRICAL SYSTEMS

The main functional units are as follows:

Power Supply
Rotation
Protection

Power supply

the incoming supply for RAC is 22 KVA from the sandynalla substation. There are two lines which are provided in case of failure from any one of the lines. One supply is given to current transformer and to the protection circuit. From this, it is stepped down to measuring device. Since the three phase power lines have to travel a large distance before reaching the centre. From 220 KV supply –stepped down to 440V. The transformer contains oil cooling and silica gel to observe moisture. The 440V is taken to distribution board and is given to various loads. If there is no need of heavy loads, a small generator of 40 KVA is used.

ROTATION

The telescope can rotate in East-west direction.

Before rotation

After rotation

There are two modes of rotation

Slew circuit
Track circuit

Slew circuit

It employs 12.5 hp induction motor at 1440 rpm located at 4 trusses (N4,S4,N10,S10)
Induction motor’s speed torque is converted to 75 rpm using gear trails.

Track circuit

Used to track the object continuously.
It employs 3-phase 5 hp motors that rotates the shaft at 3 rpm with the help of gear trails.

Usually the motors brought to a stop, the telescope strips further away from the required position due to momentum. This is a positional error.

PROTECTION SYSTEMS

Overspeed tacho circuit(need)

The telescope (ORT) is rotated at a speed of 75 rpm. Due to any fault conditions such as shaft breakage or motor failure, the telescope is subjected to overspeed. If the telescope is subjected to overspeed then the entire system would fail and telescope will be damaged, so to prevent the damage, overspeed tacho circuit is used. When the overspeed occurs, it is identified by the overspeed Tacho circuit that activates a relay.

Misalignment loop:

If any trusses are not rotated or twisted misalignment may takes place. To avoid this circuit rings are at the alternate trusses and a wire is connected in between them with a 30-v dc supply. When any misalignment occur to wires will touch the ring, which will then ac the relay to switch off supply.

Differential Synchro

The system is used to detect the misalignment in the main shaft of the ORT.

The synchro motor is fixed at both the ends of the shaft and the differential error W is fed to an electronic circuit, which operates a relay. The relay is set to trip the main supply when the misalignment goes beyond 150 in either direction.

Braking

After a track or slew operation, brakes are used to place the antenna at desired position without failing. The braking is in nature and when given a DC supply pushes the brake shoes and stops the rotation of the shaft.

Data Acquisition System For Eas At Grapes-III

Introduction

The Cosmic Ray Laboratory(CRL) is situated jus few meters above the RAC. The CRL constructed with more than 700 detectors arranged in hexagonal manner, to detect the cosmic showers from the sky by giving very high voltage to plastic scintillation squares.

Description

The very high voltages in range of 2450-volts are given to detectors,

then the output signal will given to controller section.

In this section the total signal is processed in the form of ,

TDC
ADC

Possible Radio Interferences

Spurious effects as a result of the sun appearing through distant side lobes of the telescope.
The radio interference is generated when faulty television booster amplifiers are in function.
Also potato insecticides sprayers used by farmers , will produce radio interference.
Hence to avoid it the observations in these are temporarily suspended.

CONCLUSION

The IPT which we underwent gave us a new great experience at RAC, Ooty. This training program will surely help us in our future. We would like to thank everyone at RAC, Ooty for their support and encouragement through out the training period.

here i jus gave my experience which i got through an inplant training at RAC,ooty. i got permission through Mr.K.KALYANASUNDARAM, who is working there. It is useful for those who are interested in space science and astronomy science.

Radio Astronomy Centre

admin — Sat, 10 Jul 2010 17:14:59 +0000

Radio Astronomy Centre

Tata Institute of Fundamental Research

Ooty

CONTENTS

Introduction
Construction
Electronic systems
Electrical systems
Protection systems
Data acquisition system

INTRODUCTION

The Radio Astronomy

Radio Astronomy Centre at Ooty

Selected in Nilgiri hills. The work that started in 1965 was completed by 1969. the co-ordinate latitude:11 22′ and co-ordinate longitude:-76 40′.

Ooty Radio Telescope (ORT)

CONSTRUCTION

The following are the building blocks of ORT:

Reflector
Dipole feed
Receiver

Reflector

Dipole Feed

The dipole feed consists of 1056 half wave dipoles hacked by a corner reflector and placed along the focal line on feed tracks. The physical aperture of antenna is 530 m long and 30 m wide.

Receiver

ELECTRONIC SYSTEMS

Low Noise Amplifier(LNA)

A simple technique broadband loading of FET drain, was used to ensure stability over the wideband.

Phase shifters

Scanning the beam of a radio telescope consists of an array of antennas electronically switchable phase shifters employing PIN diodes are commonly used.

Types of phase shifters:

Phase lead-lag type
Micro strip line type

The second type is used in ORT. The characteristic impedance is 50 ohm. Here extra loss of .1 db and .05 db are provided in the direct path.

Image rejection filters

It is basically a band reject filter. The o/p of 326.5 Mhz from RF amplifier is fed to this filter. The o/p is obtained is in the band region of 15 Mhz.

Mixer

The mixer is generally an adder or subtractor circuit. The o/p’s from IRF and local oscillator phase shifter to produce the sum and difference o/p of the two frequencies.

Intermediate Frequency amplifier

It is a tuned amplifier tuned to 30 Mhz and bandwidth is limited to 4 Mhz to avoid unwanted signals. The receiver gain around 100 db. The receiver system is known as Super-heterodyne receiver.

ELECTRICAL SYSTEMS

The main functional units are as follows:

Power Supply
Rotation
Protection

Power supply

ROTATION

The telescope can rotate in East-west direction.

Before rotation

After rotation

There are two modes of rotation

Slew circuit
Track circuit

Slew circuit

It employs 12.5 hp induction motor at 1440 rpm located at 4 trusses (N4,S4,N10,S10)
Induction motor’s speed torque is converted to 75 rpm using gear trails.

Track circuit

Used to track the object continuously.
It employs 3-phase 5 hp motors that rotates the shaft at 3 rpm with the help of gear trails.

Usually the motors brought to a stop, the telescope strips further away from the required position due to momentum. This is a positional error.

PROTECTION SYSTEMS

Overspeed tacho circuit(need)

Misalignment loop:

Differential Synchro

The system is used to detect the misalignment in the main shaft of the ORT.

Braking

Data Acquisition System For Eas At Grapes-III

Introduction

Description

The very high voltages in range of 2450-volts are given to detectors,

then the output signal will given to controller section.

In this section the total signal is processed in the form of ,

TDC
ADC

Possible Radio Interferences

CONCLUSION