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The amateur
radio is as hobby equally old as the radio's history. In the
radio's childhood contributed the radio amateurs to the fast
technical development within wireless communication.
The
knowledge and the technical conditions for wiresless transfer
of messages through radio waves, allowed in the verry beginning only
that “radio energy” was generated or not. Therefore, same
traffic method was used as by the wired connected telegraph
- the Morse alphabet with combinations of short and long signals.
These so-called Morse alphabetic was generated from the start with spark transmitters that gave
a radio frequent signal with a lot of wavelength's -
/frequencyspread. This traffic way had of course big
restrictions, both what it concerned the possibility that on a
simple and fast way transfer long messages. Some strong stations could block the whole
wavelength's - /frequencybands for others stations.
In order to
the society and especially the defence authorities in different nations would have good access to well skilled operators. Therefor frequency
bands was transfered for enthusiasts, licenced radio amateurs. They
would in this way amuse their skills in telegraphy and radio
technology.
Later the
amateurs found out how to generate exactly wavelengths /frequencies and modulate (to govern) these
so also speech could be transfered. Here can be mentioned the the
so-called amplitude modulation (AM), that gave the radio one rise and allowed
speech transfers to the general public. It
became during 1920´ popular to build own crystal receivers.
It was used the silicon crystal to detect and equal
aim/demodulate the audio frequent. On that way could the audio frequent
be heard
in earphones.
The radio amateurs
were at this time in full journey with developing
an amount of different circuit - solutions to improve the radio receivers' and the transmitters' properties.
Circuit solutions were developed also to ensure that a certain
transmitting frequency could be hold
with big precision.
The radioamateurs were from the authorities reduced to short
radio waves, as on that time was found as not practicable. The pioneer work the amateurs then done, contributed strongly
to that the so called short wave band came to use
for as well broadcasting as commercial purposes.
Today
offers the hobby a many different activities. It is not only
telegraphy or speech communication on the short wave bands. Also
sofisticated communication with computer transfer via
satellite on high frequency bands is on
advance.
The amateurs
low in the technical front line and participated in the
development during early 1960 so the modulation method Single Side
Band, SSB, might one huge penetration. Just it,
penetration in range possibilities. A amplitude modulated
transmitter emitted one berry wave that be modulated with the
speech frequency. This berry wave has two so-called side bands.
Through to only modulate one side band and moreover eliminating the berry
wave can the transmitter's all energy
better be concentrated to a smaller bandwidth. Hereby can also
more transmitters operating within a frequency area.
Examples on
other partial areas within the hobby is picture transmission according to
SSTV-principle (Slow Scan TeleVision),
RTTY RadioTeleTYpe, Faxes, Packetradio
(digital computer transfer, text transfer, through tonmodulation).
The
enthusiastic amateur builds still today a
part of its equipment, but it becomes all more common that factory
built radio stations constitute the amateur's starts out in the
space. These radio stations build on the last technology
and is often digitized in its circuit build up and
proves to have unique properties for frequency stability,
selectivity (average different frequencies),
noise reduction of disturbances and of course possibility to
different modulation methods and traffic ways.
The
radio waves does not take considerations to country borders and
the hobby is global. This does it necessary for a international cooperation.
IARU - international Amatörradio the union
is the body for
the national Amateur radio societies. IARU issues recommendations for how the frequency bands will be
used. They monitor the amateurs' interests vis-à-vis authorities. Overall body for all global tele - and radio communication is
ITU- international Teleunionen
ITU has
established which frequency areas that the radio amateurs
have right to send on.
A majority
of the the Swedish radio amateurs are socketed to SSA,
SSA is a
special interest organisation open for all persons that are
interested of amateur radio. The association works to
take the members' interests vis-à-vis authorities
and as cooperation body with advice and service to the members.
The total number radio amateurs in the country is about
ten thousand.
SSA deals also
with the distribution of QSL-card in all
countries. One QSL-card is a letter card with information about
the the own radio station and with which other station one has had
contact with. One confirmation card. Hard working radio amateurs can often show thousands
of QSL-cards from all the world.
Amateur radio
certificates and
admission
One
radio transmitter in the short wave bands (1,8 - 30MHz) can
at good radioconditions easy reach to others continents. Therefore, the important is that they that manages this equipment
also is surely skilled in how it functions and how
one behaves on these international frequencies. In other cases
would a few operators disturb all radio traffic over one big
area. Of this reason, each radio amateur has one own unique
callsign
as he is obliged to
send with regular intervals in order to identify itself.
Each radio amateur, irrespective of nationality, must samples on as well radio technical knowledge as traffic
rules in order to become certified of the authorities. Variations
occur, but most countries have the last years introduced one
certificate class after that the previous mandatory skill in
Morse telegraphing has ceased. Hereby has the hobby been opened
for international radio contacts also for they who earlier did not
hold the mandatory Morse skills for access of the short waves bands
The wireless
transmission conditions be issued in Sweden of
Post and Telestyrelsen PTS.
PTS prepares
regulations for among other thing amateur radio communication.
Each radio amateur be allocated a personal identification
through one “callsign”. All Swedish radio amateurs' callsigns begin with
SM, what cold for country
prefixes. (2004 was taken also the series “the prefix” SA
in use) Then, a district figure follows. Sweden are divided in districts from 0 to 7. Södermanland, Västmanland, Uppland and
Östergötland constitutes for example a district and has the figure
5. Then, it follows individual radio amateur even unique
letter combination on two to three letters.
fFrom 2004 has also the association Sweden's
Sändareamatörer got rights to certify new amateurs.
The radio in the
society's service
The radio amateurs be engaged of the society at for example
by organized search of people
and at others occasions then general communication means can be
beaten. Radio amateurs also often, been the first to heard
emergency signals from boats in distress at sea or other
expeditions in all over the the world. For all of us is the signal SOS
with the aid of the Morse alphabet well known. Three short, three long and three short signals in a
consequence. The letters be claimed to last an abbreviation of
Save Our Souls. At emergency call on telephony used
often Mayday or Emergency.
Satellite communication has already taken over the bigger part
of as well emergency traffic that commercial radio within the shipping.
For coast
near traffic like for our big lakes is used higher frequency
bands, the
VHF-band (Very High Frequenzy)
channel 16 (156,800MHz). The emergency frequency on so-called boundary
waves 2182kHz.has since some years (2002) back been replaced of
GMDSS, Globe Maritime Distress Safety System. To that comes satellite
based telephone system for commercial use.
Club activity and education
is one of the more active
clubs in Mälardalen. The club has almost one hundred members. Each Thursday evening is it “open house” in
the the club cottage located just outside of Torshälla. The club
has a modern radio equipment. Moreover contributes the club with
radio networks by various commitment as for example car rally competitions.
The club tries regularly to organize course activity for amateur
radio certificates for new members.
©2004 Anders's Svensson |