4 metres
Encyclopedia
The 4-metre band is an amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

 frequency band in the lower Very High Frequency
Very high frequency
Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...

 (VHF) spectrum.

Before World War II, British radio amateurs had been allocated a band at 56 MHz. After the war ended, they were allocated the 5-metre band (58.5 MHz to 60 MHz) instead. This only lasted until 1949, as by then the 5-metre band had been earmarked for BBC Television broadcasts.

In 1956, after several years of intense lobbying by the Radio Society of Great Britain
Radio Society of Great Britain
First founded in 1913 as the London Wireless Club, the Radio Society of Great Britain is the United Kingdom's recognised national society for amateur radio operators. The society's patron is Prince Philip, Duke of Edinburgh and it represents the interests of the UK’s 60,000 licensed radio amateurs...

 (RSGB), the 4-metre band was allocated to British radio amateurs as a replacement for the old 5-metre band allocation. For several years the 4-metre band allocation was only 200 kHz wide—from 70.2 MHz to 70.4 MHz). It was later extended to today's allocation of 70.0 MHz to 70.5 MHz.

A small number of countries in Europe and Africa have also allocated the 4-metre band to radio amateurs as a result of the decline in VHF television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 broadcasts on the 4-metre band. Movement away from the old Eastern European VHF FM
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

 broadcast band and migration of commercial stations to higher frequencies have led to slow but steady growth in the number of countries where 4-metre operation is permitted.

The 4-metre band has a unique character and because very few countries have an allocation there, very little dedicated commercial amateur equipment is available. Therefore most amateurs active on the band are interested in home construction or modification of private mobile radio (PMR) equipment. As a result there is a lot of camaraderie on the band and long ragchews are the norm, as long as there is some local activity.

Allocations and propagation

It ranges from 70 MHz to 70.5 MHz in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, with other countries generally having a smaller allocation within this window. The 4-metre band shares many characteristics with the neighbouring 6-metre
6-meter band
The 6-meter band is a portion of the VHF radio spectrum allocated to amateur radio use. Although located in the lower portion of the VHF band, it nonetheless occasionally displays propagation mechanisms characteristic of the HF bands. This normally occurs close to sunspot maximum, when solar...

 band. However, as it is somewhat higher in frequency it does not display the same propagation
Wave propagation
Wave propagation is any of the ways in which waves travel.With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves....

 mechanisms via the F2 ionospheric
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...

 layer normally seen at HF
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...

 which occasionally appear in 6 metres, leastwise not at temperate latitudes. However, Sporadic E is common on the band in summer, tropospheric propagation is marginally more successful than on the 6-metre band, and propagation via the Aurora Borealis and meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

 scatter is highly effective.

While Sporadic E permits Europe wide communication, it can be a mixed blessing as the band is still used for wide bandwidth, high power FM broadcasting on the OIRT FM band in a declining number of Eastern European countries. Although this is has lessened in recent years, it can still cause considerable interference to both local and long distance (DX
DXing
DXing is the hobby of tuning in and identifying distant radio or television signals, or making two way radio contact with distant stations in amateur radio, citizens' band radio or other two way radio communications. Many DXers also attempt to receive written verifications of reception from the...

) operation.

, no communication has taken place on the 4-metre band between Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and Southern Africa
Southern Africa
Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...

, although theoretically this ought to be possible by stations with amateur power and antenna sizes around the equinoxes. It is to be hoped that the increasing availability of the band in Mediterranean
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

 countries, where the trans-equatorial path is less difficult than from the bands traditional strongholds in Britain and Ireland, might spur such interest.

First ever TEP qso on 70mhz took place on 28 March 2011 between SV2DCD Leonidas Fiskas and ZS6WAB Willem Badenhorst

Equipment and power

Access to the 4-metre band has always been limited by access to suitable 4-metre transceivers.
A limited number of transceivers were purposely built for amateurs on this band while converted Private Mobile Radio equipment is in widespread use e.g. Phillips FM1000 and the Ascom SE550

In most countries the maximum power permitted on the band is lower than in other allocations to minimise the possibility of interference with non-amateur services, especially in neighbouring countries.
Some low power FM commercial equipment is available for the band although it is of relatively simple specifications as generally suitable for communication of up to around 50 kilometres (31.1 mi) or so with simple antennas.

In the Sporadic E seasons communication around Europe is possible with such equipment.
Currently, the only Japanese-made, "mass-market" amateur radio transceiver to cover the Four metre band as standard is the UK specification Yaesu FT-847 which was discontinued in 2005.
Because of this, many 4-metre users gain access to the band by using converted "Low band" VHF ex-PMR (Private Mobile Radio) transceivers but invariably these only have either AM or FM and those users who prefer to have a multi-mode capability but can't afford a second hand Yaesu FT-847 normally use transverters, either purposely built home builds or sometimes even converted 6-metre or 2-metre versions.

In recent years there have been extensive imports of Chinese PMR transceivers such as the Wouxun KG-699E 4m (66 MHz-88 MHz) and KG-UVD1P1LV DUAL BAND (TX/RX 66-88 Mhz /136-174 Mhz) Handheld Transceiver to Western countries mainly so far in the UK and mainland Europe.

But in recent months Qixiang Electronics, the makers of the AnyTone and MyDel transceivers have exported the AnyTone 5189 PMR 4m (66 MHz-88 MHz) transceiver from China to the UK and to Europe.

Both Transceivers have been selling extensively well in the UK and in Europe.

There also have been rumours about a 4m/6m dual band multi-mode transceiver being released in late august or early September. It is not known at this time who is manufacturing this transceiver.

Activity

In some parts of the UK the band is little utilised, while in others, notably Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...

, Bristol
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

, South Wales
South Wales
South Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...

, North London
North London
North London is the northern part of London, England. It is an imprecise description and the area it covers is defined differently for a range of purposes. Common to these definitions is that it includes districts located north of the River Thames and is used in comparison with South...

 and Hertfordshire
Hertfordshire
Hertfordshire is a ceremonial and non-metropolitan county in the East region of England. The county town is Hertford.The county is one of the Home Counties and lies inland, bordered by Greater London , Buckinghamshire , Bedfordshire , Cambridgeshire and...

, there is extensive local FM operation. There is considerable AM
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

 activity in the Dublin area. As band occupancy is relatively low, FM operation tends to take place on the calling frequency, 70.450 MHz, and AM operation on that calling frequency, 70.260 MHz. In the UK, the band is also used considerably for emergency communications, Internet Radio Linking Project links (IRLP), data links and low powered remote control.

In continental Europe the band is still primarily used for more serious DX operation. Cross-band working between the 6-metre band or the 10-metre band is common to make contacts countries where the band is not allocated.

Countries in which operation is permitted

Countries with a known band allocation:
  • Bahrain
    Bahrain
    ' , officially the Kingdom of Bahrain , is a small island state near the western shores of the Persian Gulf. It is ruled by the Al Khalifa royal family. The population in 2010 stood at 1,214,705, including 235,108 non-nationals. Formerly an emirate, Bahrain was declared a kingdom in 2002.Bahrain is...

     (69.900 - 70.400 MHz)
  • Belgium
    Belgium
    Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

     (69.950 MHz center frequency)
  • Croatia
    Croatia
    Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

     (70.000-70.450 MHz)
  • Czech Republic
    Czech Republic
    The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

     (70.100-70.300 MHz)
  • Denmark
    Denmark
    Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

     (69.9875-70.0625, 70.0875-70.1125, 70.1875-70.2875, 70.3125-70.3875 and 70.4125-70.5125 MHz)
  • Estonia
    Estonia
    Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...

     (70.140-70.300 MHz)
  • Faroe Islands
    Faroe Islands
    The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...

     (69.950-70.500 MHz)
  • Finland
    Finland
    Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

     (70.000-70.175 and 70.225-70.300 MHz)
    • Åland Islands
      Åland Islands
      The Åland Islands form an archipelago in the Baltic Sea. They are situated at the entrance to the Gulf of Bothnia and form an autonomous, demilitarised, monolingually Swedish-speaking region of Finland...

  • Germany
    Germany
    Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

     (69.950 MHz center frequency)
  • Greece
    Greece
    Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

     (70.200-70.250 MHz)
  • Greenland
    Greenland
    Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

     (70.000-70.500 MHz)
  • Ireland (Republic of) (70.125-70.450 MHz)
  • Italy
    Italy
    Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

     (70.0875-70.1125, 70.1875-70.2125 and 70.2875-70.3125 MHz)
  • Luxembourg
    Luxembourg
    Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...

     (70.150-70.250 MHz)
  • Monaco
    Monaco
    Monaco , officially the Principality of Monaco , is a sovereign city state on the French Riviera. It is bordered on three sides by its neighbour, France, and its centre is about from Italy. Its area is with a population of 35,986 as of 2011 and is the most densely populated country in the...

     (70.000-70.500 MHz)
  • Namibia
    Namibia
    Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

     (70.000-70.300 MHz)
  • Norway
    Norway
    Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

     (70.0625-70.0875, 70.1375-70.1875, 70.2625-70.3125, 70.3625-70.3875 and 70.4125-70.4625 MHz)
  • Portugal
    Portugal
    Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

     (70.1570-70.2125 and 70.2375-70.2875 MHz)
    • Azores
      Azores
      The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...

    • Madeira
      Madeira
      Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...

  • Romania
    Romania
    Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

     (70.000-70.300 MHz)
  • Slovakia
    Slovakia
    The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

     (70.250-70.350 MHz)
  • Slovenia
    Slovenia
    Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...

     (70.000-70.450 MHz)
  • Somalia
    Somalia
    Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...

     (70.000-70.500 MHz)
  • South Africa
    South Africa
    The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

     (70.000-70.300 MHz)
  • Spain
    Spain
    Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

     (70.150 and 70.200 MHz)
  • UAE (70.000-70.500 MHz)
  • United Kingdom
    United Kingdom
    The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

     (70.000-70.500 MHz)
    • Gibraltar
      Gibraltar
      Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...

    • Guernsey
      Guernsey
      Guernsey, officially the Bailiwick of Guernsey is a British Crown dependency in the English Channel off the coast of Normandy.The Bailiwick, as a governing entity, embraces not only all 10 parishes on the Island of Guernsey, but also the islands of Herm, Jethou, Burhou, and Lihou and their islet...

    • Isle of Man
      Isle of Man
      The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...

    • Jersey
      Jersey
      Jersey, officially the Bailiwick of Jersey is a British Crown Dependency off the coast of Normandy, France. As well as the island of Jersey itself, the bailiwick includes two groups of small islands that are no longer permanently inhabited, the Minquiers and Écréhous, and the Pierres de Lecq and...

    • St. Helena

Countries with past or current experimental operation

In "experimental" countries, authorities authorized amateur radio experiments on the band for a limited period of time.
  • Hungary
    Hungary
    Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

     (70.000-70.500 MHz)
  • Sovereign UK bases in Cyprus
    Sovereign Base Areas
    The Sovereign Base Areas are military bases located on territory in which the United Kingdom is sovereign, but which are separated from the ordinary British territory....

     (70.000-70.500 Mhz)
  • An automatic beacon has also been authorized in Austria
    Austria
    Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

     & Cyprus
    Cyprus
    Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...



Other
  • United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

     has one experimental transmitter in Virginia transmitting CW on 70.005 MHz. Call sign is WE9XUB.
  • Poland and the Netherlands will soon gain access to the 4-metre band around January 2012
  • Glen Zook, K9STH, the Head Moderator of QRZ.com and a longtime magazine writer on VHF related topics, filed a petition with the U.S. Federal Communications Commission on 27 January 2010 to create a new U.S. 4-Meter amateur radio allocation at 70 Mhz to parallel those in Europe and other parts of the world.

Common Uses of the 4-meter band

  • FM
    Frequency modulation
    In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

     Simplex
    Simplex communication
    Simplex communication refers to communication that occurs in one direction only. Two definitions have arisen over time: a common definition, which is used in ANSI standard and elsewhere, and an ITU-T definition...

  • AM
    Amplitude modulation
    Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...

     Simplex
  • Packet radio
    Packet radio
    Packet radio is a form of packet switching technology used to transmit digital data via radio or wireless communications links. It uses the same concepts of data transmission via Datagram that are fundamental to communications via the Internet, as opposed to the older techniques used by dedicated...

  • SSB
    Single-sideband modulation
    Single-sideband modulation or Single-sideband suppressed-carrier is a refinement of amplitude modulation that more efficiently uses electrical power and bandwidth....

     voice operation
  • Morse code
    Morse code
    Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...

     (CW) operation
  • DX
    DXing
    DXing is the hobby of tuning in and identifying distant radio or television signals, or making two way radio contact with distant stations in amateur radio, citizens' band radio or other two way radio communications. Many DXers also attempt to receive written verifications of reception from the...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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