The Pine Valley Repeater Amateur Radio Club
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The Pine Valley Repeater Amateur Radio Club |
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Ever since Marconi and Jagadish Chandra Bose transmitted the first radio signals about one hundred years ago, amateur experimenters have played an important role in the development of radio communication.
In the first part of the twentieth century, radio experimentation by members of the public was tolerated by the governements and radio amateurs were confined to bands which were considered 'useless' for commercial or public use. After World War II, the vast amounts of surplus equipment, which became available, greatly stimulated amateur radio.
Now, new developments in computers, microcircuits and materials offer amateur radio a bright new future.
One of the most fascinating aspects of amateur radio, is making radio contacts with other radio amateurs all over the world. And sometimes in remote locations.
Very often friendships for life are made between radio amateurs, carrying out experiments with various equipment and modes, and often with advanced communication techniques.
The Shortwave Listeners ( SWL ), may also contact these amateurs by sending them a QSL card, a postcard-size report which confirms the reception of a radio contact made by two amateur stations.
A large percentage of the amateurs prefer experimenting with components and circuits. Others use the computer as an entry point to the hobby. A great variety of equipment is used.
Many of the older radio amateurs will perhaps recall with nostalgia 'the good old days' before the existence of computers. Back then the only equipment in a 'radio shack' was a radio receiver, a transmitter, and a keyer.
In many countries, radio amateurs have founded Amateur Societies which provide forums to exchange ideas and also to protect the interests of the Radio Amateur Service. This is , in principle, not very different from the role of learned societies which cater for the interests of electronics professionals.
Furthermore, since many professional electronics engineers and technicians are also radio amateurs, the distinction between 'amateur' and profession can become very much blurred.
Those who pass a written exam - no Morse code is required - is issued a license by the FCC. This license is unique, and is issued by the licensing authority, usually a government department.
The callsign is issued by the FCC at the time of granting a licence.
A licence can only be obtained after successfully passing an amateur radio examination, also conducted under the scrutiny of the licencing authority. The licence permits the radio amateur to carry out experiments in communications by radio, subject to a set of conditions which can be quite complex.
Many radio amateurs started their hobby listening to shortwave radio. Starting with radio broadcasts from distant countries, they become interested in receiving weak or distorted radio signals on congested frequency bands. A very popular aspect of his hobby is to monitor radio communications on the many frequency bands, allocated by international agreement to amateur radio.
Receiving other kinds of radio transmission, like standard time signals and police scanners, may sometimes be very interesting. The reception of signals from radio beacons can provide usefull information about the propagation of radio waves.
The SWL individual very often builds his own equipment, from antennas to receivers and signal processors. And with the availability of personal computers, other communication modes, such as weathermaps, radio telex bulletins, slowscan television and PSK31 have become increasingly popular.
Radio communication - including communications by radio amateurs - is regulated on an international level by the International Telecommunication Union, ITU, a United Nations body. This organization has assigned to each country in the world a unique code to identify the radio stations which it administers. The code consistes of a short number of characters.
Each amateur radio station is assigned a station identifier - the callsign - which is unique for the entire world.
The call sign consists of two or three parts. For instance: The callsign W9PVR is composed of a prefix (W), a number (9) representing the call area in the U.S. in which the radio station is located, and the suffix (PVR). In the case of W9PVR, the call is a "vanity" call especially requested by the Pine Valley Repeater Amateur Radio Club. So:
In some countries short wave listeners are also issued with an identifying code. The identification is assigned by the association with which they are affiliated.
In the Netherlands, for instance, the issuing government body distributes NL-numbers. In Belgium distributes ONL-numbers and the GOS-listeners (from the former Soviet Union) are identified by U-numbers. So, you may be confronted with 'NL8800', 'ONL2820' or 'UA3-170-112', indicating SWL's from Holland, Belgium and GOS respectively.
APRS is different from regular packet in four ways. FIRST by the integration of maps and other data displays to organize and display data, SECOND, by using a one-to-many protocol to update everyone in real time, THIRD, by using generic digipeating so that prior knowledge of the network is not required, And FOURTH, since 1997, a worldwide transparent internet backbone, linking everyone worldwide. APRS turns packet radio into a real-time tactical communications and display system for emergencies and public service applications (and global communications). Normal packet radio is useful in passing bulk message traffic (Email) from point- to-point, but it does not do well at real time events where information has a very short life time and needs to get to everyone quickly.
APRS is a LOCAL RF network. Although the Internet monitors APRS worldwide, this is not the primary objective. But like all of our other radios, how we use APRS in an emergency of special event is what drives the design of the APRS protocol. Although APRS is used 99% of the time over great distances, and benign conditions, the protocol is designed to be optimized for short distance real-time crisis operations on RF.
APRS provides universal connectivity to all stations in the net by avoiding the complexity and limitations of a connected network. It permits any number of stations to exchange data just like voice users would on a voice net. Any station that has information to contribute simply sends it, and all stations receive it and log it. Secondly, APRS recognizes that one of the greatest real-time needs at any special event or emergency is the tracking of key assets. Where is the Event Leader? Where are the emergency vehicles? Whats the Weather at various points in the County?
To answer these questions, APRS transmits and captures the location and status of all stations. It can be used over any 2-way radio system including HAM, CB, Marine Band, etc.
APRS is on 144.39 throughout the North American Continent. Other countries may use other frequencies. Check locally.
Here are a couple of interesting sites as suggested by Chris, KC9CMD: Google Maps APRS or More about APRS
With the explosive growth of computers and miniaturised electronic systems, one may ask if there is still a future for amateur radio. The answer is an unqualified YES.
It is also pointed out that commercially available transceivers can outperform the home-made equipment at considerably lower cost. Furthermore congestion in the amateur frequency bands and interference caused by illegal broadcasting stations (often funded by national sources), make it hard for the beginning amateur operator to make radio contacts.
The advent of multi-media computers, low cost microwave transistors, complex integrated circuits and new materials and components, has expanded possible remedies a great deal.
Special digital modulation techniques, such as 'spread spectrum', can be used for point-to-point transmissions. A new domain for people who prefer to replace complex hardware by programming a personal computer.
Small size and low weight of equipment nowadays and the almost unlimited possibilities to travel to any place on earth, should appeal to the young adventurer.
Working at even higher frequencies is a challenge to the technically oriented amateur. Generating stable frequency at microwave frequencies can be very difficult. Commercial interest in these frequencies is usually broadband, whereas amateur radio mostly use narrow bandwidth systems.
New electronic components can be used in sensitive ultra high frequency transceivers, which can be used to bounce radio waves off natural obstructions, such as the moon (EME) or ionized layers in the atmosphere
Space communications, using amateur satellites, should appeal to the amateur with modest skills in communication practice and technology.
It may occur that an amateur payload is sent on an interplanetary mission. This will require the efforts of a great many amateurs. The constructing of a ground station is comparable with that of an EME station and many of these will have to work under remote control, in a manner comparable to that of a radio telescope. This poses a challenge for the computer programmer as well as for the amateur oriented on radio techniques.
The Internet opens up this new field for radio amateurs who enjoy using their multi-media computer. The added value to Amateur radio could be great.
Other functions of ham radio are: Distribution of general information, radio bulletins, articles
Training and education.
Publishing club activities.
Remote and 'real-time' operation of equipment for experimental purposes.
