DP Tool Club 17/CD_ASCQ_17_101194.iso/dos/fr/radiodx3/guide.txt

Text File | 1994-05-04 | 12KB | 242 lines

                       THE BEGINNER'S GUIDE TO DXing


   LONG WAVE, SHORTWAVE etc...

   When eletricity was first harnessed in the 19th century direct current
   was used. Batteries were the power source, and these small subatomic
   particles called electrons flowed from one part of the battery, through
   wires to do the necessary work, and back to another part of the battery.
   Alternating current is an improvement in which the flow of electrons is
   reversed a set number of times every second. This is the frequency, and
   it's measured either in cycles per second or Hertz ( abbreviated Hz ).
   In both cases it's measurement of how many times the flow of electrons
   in a circuit changes direction and back in one second. In the Americas
   most house current runs at 60 cycles per second, or 60 Hz, while in the
   rest of the world the most common frequency for electricity is 50 Hz.
   Radio came about with the discovery that above a certain frequency waves
   were created that could leave their original circuit and travel away.
   Besides measuring the frequency of a particular wave, you can also
   measure the distance that wave travels during each electric cycle.
   That's wavelenght, and if you multiply it by frequency you'll always get
   the speed of the radio waves, which is the speed of light.
   Frequencies are normally referred to as Kilohertz (Khz) or Megahertz (Mhz)

   Kilohertz is equal to 1000 Hz
   Megahertz is equal to 1000 Khz

   Sometimes frequency referred to in meters which i a measure of the wave
   lenght. Many modern communications reicevers are calibrated only in
   frequency with no markings in meters.

   Formulas equating frequency and wavelenght are as follows:

                        300000                                  300000
   Wavelenght (M) = ───────────────        frequency (Khz) = ──────────────
                    Frequency (Khz)                          Wavelenght (M)

   Shortwave run from 3 Mhz up to 30 Mhz. The bands above shortwave are
   called VHF -- Very High Frequency, UHF -- Ultra High Frequency, and so on,
   up to light waves and beyond. But let's concentrate now on shortwave,
   which is the most important for international broadcasting.

   There is a layer in the Earth's atmosphere called the ionosphere, which
   is charged by the sun. This gives it the ability to reflect some radio
   waves, like a giant mirror in the sky.
   That's what makes radio communication over long distances possible --
   signals are sent up into the air, are reflected by the ionosphere, and
   return to Earth, hundreds, perhaps thousands of kilometers aways.
   Not all radio frequencies will reflect. Those that are too low are
   absorbed. Those that are too hight go right on through the ionosphere.
   These upper and lower limits are constantly varying, depending on the
   relationship of the sun to the Earth -- such factors as time of day,
   season, and the sun's 11 year sunspot cycle.
   Generally it's the shortwaves which reflect, but the constant changing
   of conditions is what makes radio listening an unpredictable and
   fascinating hobby.

                                   -- 1 --
   HOW TO GET STARTED

   The most important tool for a radio listener is the receiver, the box
   you use to listen to the world.
   The fist thing that needs to be said is that often it's not the receiver
   but the amount of experience one has that's most important.
   Radio listening experts can often uncover all sorts of stations on the
   most basic receivers.
   They know what to look for an when to look for it. That said, a receiver
   with advanced features can make things a lot easier, for both the begin-
   ner and the experienced listener.

   In the last few years the microchip revolution has created a new gene-
   ration of shortwave receivers. They're smaller, more sensitive, and
   less expensive than those of the past.
   There's also a bewildering array of new offerings, often widely differing
   in price, so it's important to know exactly what you looking for.

   Size is one consideration -- if you want to take your receiver with you
   trekking in the mountains, don't buy a large desk model suitable only
   for armchair exploring.
   Frequency coverage is another consideration. Does the receiver cover all
   the bands you want ? If you only want to listen to shortwave broadcast
   stations, a receiver that only has those bands will do.
   But it won't do if you want to hear ship-to-shore, airplanes, or amateur
   radio operators...

   The two most important technical standarts are sensitivity and selecti-
   vity. Most of new receivers are very sensitive to radio signals. But they
   often fall down in their ability to select between stations on adjacent
   frequencies.
   Every year the "World Radio TV Handbook" publishes a review of current
   receivers.
   The WRTH is available at many bookshops, or you could browse though
   a recent issue at a local library.
   Radio Netherlands publishes a regular "Receiver Shopping List" free of
   charge. If you'd a copy of the most recent list write to :

                         Radio Netherlands
                         Box 222
                         Hilversum
                         Netherlands

   The next important piece of equipement is the antenna. Fortunately,
   current receivers are often so sensitive that they often work well with
   a built-in antenna. Not always of course -- and if you live inside a
   concrete and steel building you will definately want something out of
   doors.
   The basic rule with antennas is to string up a wire as long as and as
   high as possible.
   While you be very careful about measurements for transmitting antennas,
   receiving antennas are very forgiving about lenght.
   The most important thing to remember is to keep your antenna away from
   power and telephone lines.
   The simpliest thing to do is throw a couple of meters of wire outside
   a window.
   If you want information about more advenced antennas, Radio Netherlands
   also provides a free booklet on the subjet.

                                   -- 2 --
   WRITING TO STATIONS

   While most radio communication is two-way, radio broadcasting is generally
   a one-way activity. They make programs, you liten ...
   Fortunately there are means for listeners to contact stations,by mail for
   example.
   If there is station you want to listen to, or if you hear a broadcast and
   want to know the entire time and frequency schedule, the easiest thing
   to do is to write the station and ask for a schedule.
   International broadcasters are usually delighted to send you one, and may
   even put you on the mailing list to receive regular copies.
   Stations usually gives their addresses on the air.
   Otherwise you can consult a "World Radio TV Handbook", at the library
   if you don't have one at home.

   Often the simpliest thing to do is to write the name of the station, the
   city it is in -- which in the case of large international broadcasters
   is usually the capital city -- and the country.
   In most cases that's enough. Most stations you hear on shortwave are
   supported by national governments, and can afford return postage. But
   smaller independent stations, an especially medium wave and other
   domestic outlets, often can't afford postage to listeners abroad.
   If you write to such stations, it is best to include one or two
   International Reply Coupons, which are available at local post offices
   in most countries outside of Eastern Europe.

   When shortwave broadcasting began, it was hard for stations to know if
   they are being heard. They encouraged listeners to send reception reports
   and these were usually rewarded by letters or cards known as QSL cards.
   QSL is an old telegraphy abbreviation for "I confirm", and QSL cards
   confirm that you the listener have indeed heard a particular station.
   Nowadays, with monitors and monitoring agencies to advise stations, the
   need for reception reports is far less. A number of stations have
   discontinued sending QSLs in order to save money, but most continue to
   provide them, as courtesy to listeners.
   Many listeners no longer bother to collect the cards. Nevertheless, many
   smaller and independent stations stillwant reception reports, and QSL
   cards are needed for contests or DX diplomas.

   If you send a reception report to a station, remember to include : Date
   and Time in GMT (or UTC), the frequency of the broadcast, notes on
   reception conditions, and some program details.
   Many reports just said "man talking" or "local music". That isn't enough
   -- you have to prove you heard the station.
   If the program is in a language you don't understand, try to find some
   details anyway, perhaps the sponsor of a commercial, the subject of a
   talk,or news datelines.
   Conditions are often given in the SINPO code, on a 1 to 5 scale, from
   worst to best :

                          S = Signal strenght
                          I = Interference
                          N = Noise (static)
                          P = Propagation (fading)
                          O = Overall

   Remember 5 means a station sounds as good as a local, so don't just give
   out a 5 because you want the station to like you. Honest reports are
   most appreciated.
                                   -- 3 --

   In the case of smaller stations without external services you should
   probably try to write in the country's own language and use local time
   rather than GMT.
   Many clubs provide reception report forms in several languages.
   For more information about Radio DX Clubs see the DXCLUB.LST file ...
   The most important thing to most stations is that you think of programs.
   Stations want to make better programs, and actually appreciate it more
   if you criticise and tell them what you didn't like than if you just
   write and say you think they are wonderful.


   KEEPING UP-TO-DATE

   Because of changing propagation conditions, most international broad-
   casters change frequency schedules four times a year. In addition,
   stations often make adjustements to schedules at other times.
   Local stations often stay on the same frequency for years, but with so
   many radio stations in the world, there's always something happening
   -- a new frequency, a time shift, a new language, a new station appearing
   or an old one disappearing.

   The standard reference is the "World Radio TV Handbook". This annual
   publication lists virtually every radio and TV station in the world.
   No one in the radio listening hobby can be without it.
   It is sold at many bookshops and by many radio clubs.

   There are also a number of magazines sold at newsstands in different
   countries with columns for shortwave listeners.

   The most recommended programs in English are Radio Netherlands "Media
   Network" on thursdays, Swiss Radio International's "Swiss Shortwave
   Merry-Go-Round" two saturdays a month...

   Don't forget "Media Scan" (formerly Sweden Calling DXers) presented by
   Radio Sweden International 1st and 3rd tuesday...


   BIBLIOGRAPHY

   THE BEGINNER'S GUIDE TO DXing

   RADIO SWEDEN INTERNATIONAL
   S-10510 STOCKHOLM   SWEDEN


      I hope this guide  will help you to get more enjoyment from your
      listening ...

                          Best 73's

                                           Maurice SCHOCH







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