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An Introduction:
Long Distance Medium Wave Listening

by Steve Whitt

1. Introduction
This booklet is a guide to long distance listening (DXing) on the Medium Wave (MW) band. If you've never tried listening to anything other than your local radio station on MW then this booklet is intended as a "road-map" to this uncharted area of the radio hobby. It will give you an insight into the stations you could hear and how to identify them. Also covered are the types of receivers and aerials you should use and an introduction to signal propagation. Of course once you've caught an interesting station you will probably want a QSL card, so this booklet also includes information that should make this task easier. Naturally a guide like this can only scratch the surface of MW DXing so it needs to act as a pointer towards more information and indeed you'll find up to date listings of suitable books, clubs and sources of specialist equipment.

MW DXing opens up another dimension not covered by most of the shortwave (SW) bands. Although a few MW broadcasts are also available on SW the vast majority are unlikely to be heard on SW frequencies. Indeed many countries (mostly island nations) have no SW operations and only broadcast on MW which means that MW DXing is the only way of logging these elusive parts of the world. Furthermore most MW stations are local in nature and thus can give an interesting insight into what is going on locally; one can hear farm news from the US mid-west, obituaries on Jamaican radio; war reports from the former Yugoslavia, religious salvation from many stations and adventures from ship borne broadcasters on the high seas. The choice is yours!

Good listening.

2 Who goes there?

2.1 Medium Wave Stations

The Medium Wave (MW) band is an internationally agreed band of frequencies primarily set aside for the purpose of broadcasting. It is also known as the AM or MF band or the Broadcast Band (BCB) in various parts of the world. Indeed there are stations using this band in every continent (except Antarctica) and to appreciate the sheer numbers of broadcasters just consider that in the USA alone there are about 5300 stations on 106 channels in the AM band. For many years the MW band has stopped at approximately 1610kHz but it is gradually being extended to 1705kHz in North America. What sorts of signals can you hear on the MW band?

International Broadcasters:

Mostly found in Europe and South East Asia, these stations are designed to target audiences in countries distant from the transmitter and studios. Good examples are high power (500kW and upwards) transmitters operated by the Voice of America, BBC and Radio Moscow. Over the years these stations have been joined by a selection of religious broadcasters such as Vatican Radio, PJB in Bonaire, TWR in Monaco and HLAZ in Korea.

Regional Broadcasters:

These are best exemplified by the Clear Channel stations in North America. These 50000 Watt stations have the exceptional privilege of having a MW channel virtually to themselves. This is a deliberate move to ensure that the vast rural interior can get good radio reception at night when coverage of half the continental USA is typical.

Synchronised Networks:

These are networks of several stations all on one frequency carrying the same programme set up specifically to provide national coverage. Such networks need care in their design and operation to avoid problems with carrier frequency synchronisation and variable delay in the distribution of audio to each transmitter. The most notable examples of synchronised networks are run by the BBC in the UK for distribution of Radio 1 and the news and sports network. The network operated by Virgin 1215, also in the UK, is less successful.

Local Broadcasters:

By far the majority of stations on the MW band fall into this category, characterised by the co-location of the station, its studios and transmitter and its audience. Transmitter powers can range from as little as 1W to 100kW or more, depending on the coverage area and the degree of co-channel interference. Many local broadcasters in North America operate only during daylight hours in order to avoid problems with co-channel interference brought in by the night-time sky-wave.

Navigational Beacons:

Radio signals are an essential means of navigating for most ships and aeroplanes and the frequencies between the Long Wave band and the MW band have been allocated for this purpose. More surprisingly, a sizeable number of aeronautical beacons operate in the MW band interspersed amongst the broadcasters. Over 100 beacons are known, of which the majority are in the former Soviet Union. Beacons are usually low power and intended to give accurate navigational information over 50-100 nautical miles range, however long distancelisteners (DXers) will be able to detect the repetitive Morse code identification messages from beacons over much greater distances.

Clandestines, Pirates and Jammers:

Most signals described so far are more or less permanent features in the MW landscape. However, there are several more transient types of signals which can be heard, the most prominent of which are pirates and clandestine operations. Pirates are stations operating openly with out official licences from any country. They range from one time hobby pirates operating from someone's bedroom to fully financed operations broadcasting from ships at sea. The heyday of the seaborne pirate seems to be gone since the likes of Radio Caroline, Voice of Peace and R New York International have passed into the history books. Just two radio ships are still operational, both in the Mediterranean.

Clandestine stations are usually politically motivated broadcasters often supported by a covert government operation. Operations are complex since stations can pretend to be what they are not and there is always the possibility of the double bluff! These stations come and go, reflecting political changes in their "host" country. Currently the bulk of known clandestines are operating in the Middle East. Long serving examples include National Radio of the Saharan Democratic Republic (since 1975) and the Voice of Iraqi Kurdistan (since 1965).

Clandestine stations, as well as official broadcasters, are often the target of jamming if the government in the area targeted by the broadcaster feels threatened by the message being carried. Jamming usually takes the form of a powerful transmitter broadcasting irritating noise and interference on the same frequency as the station beaming into the country. Jamming on MW has fallen dramatically since the late 1980s and now is confined mainly to the Middle East and the Korean peninsula.

2.2 Long Wave Stations

Though the Long Wave (LW) band (148.5 - 283.5kHz) is not strictly part of the MW Band, many listeners have common interest in the two bands. Long Wave is only used by broadcasters in Europe, North Africa, Mongolia and the Asian part of the former Soviet Union. Elsewhere in the world these frequencies are used mainly by navigational beacons similar to those found between 283.5 and 525kHz. One exception is in the USA where 160-190kHz is also used by experimenters who are allowed just 1W of power to tiny antenna!

3 Getting Started

Let's take a brief look at what's needed to become a MW DXer and how you get started. Firstly, it is important to realise that the MW DXer can start listening with very cheap and simple equipment; any domestic radio will tune the MW band and it is quite easy to hear 50 - 100 different stations at night using just an internal aerial. However, it is probably preferable to use a better quality domestic radio, or a good car radio to get started. With this type of equipment, stations from up to 1500km away will be regularly heard at night. If radio conditions are favourable and you listen at the right time, reception of some stations over 3000km away should be possible. In this way you can have a go at DXing the MW band before committing yourself to any more sophisticated (or expensive) equipment. On the other hand, if you are already an active short-wave listener, all that is needed to get going on MW is a change of waveband. Indeed many SW listeners tend to overlook the fact that their radios can usually tune the MW band and that their outdoor aerials are often effective in picking up distant MW signals. For the SW listener who has grown tired of the mega-watt international stations, a fresh challenge can be found on the MW band.

3.1 Round The Clock

It is possible to DX on the MW band 24hrs a day (provided you don't need to sleep!) but the band has two distinctly different "personalities" according to the time of day. During daylight hours MW radio signals are absorbed in the lower layers of the ionosphere and only "ground-wave" signals propagate; these signals radiate away from the transmitter rather like ripples in a pond and allow reception at distances up to about 500 km. Daytime is a good time to listen for low power local radio stations since very few distant signals are audible and therefore interference is at a minimum.

At night the ionosphere tends to reflect, rather than absorb, MW signals and thus energy radiated upwards from a transmitter is refracted back down to earth at some point far away from the transmitter. These are known as skywave signals. It is quite possible for night time signals to under go multiple hops with alternate reflections occurring in the ionosphere and off the earth's surface. This mechanism allows reception to take place many thousands of km away from a transmitter. For example Radio Globo in Rio de Janeiro, Brazil is regularly heard in Europe, its signal having to cross 9500km of ocean on the way. You will of course notice that night time sky-wave propagation fills your radio dial up with hundreds of powerful signals, so how is it possible to hear the weak DX signals?

Over the years international broadcasting organisations have agreed a band plan arrangement on the MW band which requires all stations in an area to operate on fixed frequency channels. This has been arranged to maximise the number of broadcasters who can operate and to minimise the degree of interference affecting the listener. Fortunately for the DXer, international agreement is not perfect and as a result different MW band plans are operated in different continents; most European, African and Asian stations use channels that are exact multiples of 9kHz, whereas in the Americas channels are assigned as multiples of 10kHz. This means that, in Europe for instance, by tuning between the 9kHz channels reception of trans-Atlantic stations becomes possible. For example;

1008kHz (112 x 9kHz) NOS Radio 5 Hilversum, Holland

1010kHz (101 x 10kHz) WINS New York, USA

1017kHz (113 x 9kHz) SWF Baden Baden, Germany

This particular example also illustrates the value of knowing a station's timetable. Although reception of WINS is technically possible as soon as a path of darkness exists between New York and Europe, NOS is a pretty powerful signal and will cause interference. However NOS signs off for the night at the unusually early time of 2200hrs (GMT) and knowing this it is possible to tune a virtually interference free signal from WINS before midnight.

Stations on split frequencies are usually the easiest to hear over long distances since they suffer less co-channel interference. Obviously in any part of the world reception conditions vary and different stations are heard. In order to gauge what you are likely to hear or what you are going to have real difficulty catching it is worth joining a local club that includes MW in its remit; even better would be joining a specialist MW club [see Section 6.1] since you will have access to lots of information on MW listening and in particular you'll be able to see what other enthusiasts are hearing.

3.2 Confirming Your Reception & Getting a QSL

These three letters, QSL, are probably a bit of a mystery to the newcomer, so what do they mean? Let us suppose you've just heard Radio Fiji on your pocket transistor radio how are you going to convince everyone that you weren't just dreaming? Wouldn't it be good to have something from the radio station confirming that you really did hear them? Well this is where QSL cards come into the picture; a QSL card is usually a picture postcard (although it can also take the form of a letter, a certificate, or a folder) sent to a radio listener by a radio station confirming that reception actually took place.

In order to get a QSL card from a station there are several things you need to do, but firstly remember that you have to hear the station and then convince station staff that you did hear their signal. Normally one is obtained by sending a station a reception report giving details of how well their signal was received and of the programme material heard, as proof of reception. Naturally you need to say when you were listening (date and times should be in GMT/UTC or in the stations own local time).

Historically, the QSL originated in the days when stations relied entirely on reports from listeners to determine their coverage area. In fact the letters "Q-S-L" are based upon a radio operators shorthand code (Q code) system that evolved during the early days of radio. Nowadays, however, many stations use reports from professional monitoring stations and have more accurate coverage predictions available, and consequently the QSL survives largely as a service, from the station's point of view. Additionally there is a significant difference in QSL policy between the international short-wave broadcaster, which issues QSL cards to maintain contact with and to gauge the size of its audience, and the local medium wave station being heard outside its usual coverage area. At best, the latter will treat a far off reception report with curiosity and will send out a QSL as a public relations exercise. At worst, to a station with few staff and a limited budget, reception reports from DXers can be a downright waste of time. It is therefore vital that MW DXers follow some simple guidelines when sending out reception reports to stations.

Firstly I would suggest a personal letter to the engineer or manager together with a detailed report of reception conditions (was the signal strong? what was interfering?) and adequate programme details to prove that you really heard the station ("music and talking" is not good enough) are the basic requirements. Additionally make a polite request - not a demand - for a QSL card or a letter confirming reception, and remembering that most MW stations are local operations run on limited budgets it is wise to write to them in their own language (or that used in the programme) and to enclose return postage in the form of an International Reply Coupon (available at Post Offices), or appropriate mints stamps.

This may all seem a complicated procedure but if you follow these tips not only should you receive more QSL cards for your own collection, but you will help maintain good relations between radio stations and the DX fraternity in general.

3.3 The Identification Question

If you tune in to your local radio station it soon reveals it identity through a number of clues; its strength, frequency, programme style and most importantly its on air ID (callsign, jingle etc.) which is easily heard since there is no interference. We now need to ask what happens when you are trying to decipher a weak, fading signal from a distant station that may well be using an unfamiliar language. The fundamental question is, at what point is a station identified and how should a station that is not fully identified be described.

The process of identifying stations should be viewed as a broad spectrum of probability. At one end is the completely unidentified station, an example of which is the open or blank carrier with no modulation - although you may have quite a good idea about its identity such a signal really is unidentified. At the other end of the spectrum is the positively (100% probability) identified (e.g. "...the powerful missionary outreach station, the Atlantic Beacon 50000 Watts at 15-70, broadcasting from the beautiful Turks and Caicos Islands in the West Indies..." leaves little doubt about this station's identity!).

Many DX stations fall somewhere between these two extremes; for example you may hear only part of a callsign perhaps in a poorly understood language, or maybe in the midst of heavy interference or jamming. Or perhaps no identification is heard but certain characteristics of the signal or programme content point in the direction of one particular station. Generally speaking, the longer you listen to a station, on one date or over many days, the more clues there are to help achieve successful identification. If you can't ID a station keep listening!

The factors which contribute to the identification of a station are almost without limit. Among them are time of reception, frequency, quality of signal, and programming style. The latter is usually one of the most important clues since valuable information can be gleaned from the languages used and music played, as well as from advertising, weather reports, time checks and so on. It should be appreciated that one's ability to identify a station depends mostly on the ability to interpret what is being heard. And, rather like a detective investigating a crime, it takes experience as a DXer to reach a correct conclusion based upon the limited clues available. Even the most experienced DXer will not be able to identify everything heard, so there needs to be some way of indicating how certain (or uncertain) a particular identification is. Hence the following shorthand expressions have developed as a solution to this problem.

Identified: Implies that the listener is 100% certain of a station's identity since a full announcement by the station was clearly heard.

Presumed: When a station is listed as presumed it means that the listener has had sufficient clues to the station's identity to be almost (90-99% probability) certain of its true identity. About all that is missing is a formal ID announcement.

Tentative: This term usually describes a situation where the listener is fairly certain that a particular station is being heard - indeed that the probability is substantially greater than 50%, typically from 75%-90%. It is important, however, to note that a tentative logging is not just a pure guess since there still have to be a number of clues pointing in the right direction.

Unidentified: Anything short of tentative is called "unidentified" and the DXer should resist the temptation to classify loggings as tentative if there is insufficient evidence. When there is any doubt about a logging, it is wise to err on the side of caution and list it as unidentified; however it may be worth indicating which station you think it might have been if you have an idea.

At this point a word of caution is probably in order with regards to station listings. All DXers use lists of one sort or another to help them in their hobby (e.g. WRTH, club bulletins etc.) but it is dangerous to rely on a list (even the most up to date) as the sole means of identifying a station. That is not to say that lists should not be part of a DXers "tools of the trade", but just that caution should be exercised in their use.

Lists are invaluable to help narrow down the range of possibilities when it comes to indentifying a mystery station; they can also guide a listener to the right place on the dial to possibly hear a particular station, but they cannot actually identify a station - only the station itself can do that.

Over reliance on lists and a bit of related "wishful thinking" results in the practice known as "list logging" which can be sometimes observed as anomalous loggings reported in the DX logs of some magazines and club bulletins.

3.4 DXing in Your Sleep!

The easiest way to identify a MW DXer is if they fall asleep during the day. Since the fundamental characteristics of the ionosphere favour long distance MW radio reception at night this hobby will be the province of the shift worker, the insomniac or the outright fanatic. There is one solution and that is to DX in your sleep!

All you need apart from the standard aerial and receiver is a tape recorder and a timer and a fairly methodical approach to listening. Neither the tape recorder nor timer should be expensive and indeed I don't know any serious DXer (SW or MW) who doesn't already use a recorder. Depending on your selection of equipment there are two ways of DXing in your sleep.

If you have an ordinary radio and a separate cassette recorder you'll need to buy a mains timer unit (get one with a digital display since these can be set precisely to the minute) which will cost about £15 - £20 (US$20-40). With such a timer connected in series with the mains lead of the recorder you are able to make a recording at any time of the day or night when you're not around. Just make sure that your radio is tuned to the frequency of the station you want to hear. Unfortunately such remote control is trickier for really tough DXing since in these circumstance you will want to be making continuous adjustments to your receiver or aerials to improve reception. However, for less marginal conditions this technique is very valuable particularly for night after night monitoring of one frequency. I use it, for example, for monitoring 1440kHz after R. Luxembourg closes down. In this case it would be impossible for me to be awake every night and I soon would get put off by the DX-less nights. Indeed taping for an hour each night allows me to quickly find the nights that are particularly good for DX (just 5-10% say) and to then examine the tape more closely for DX signals. In this way on 1440kHz I've heard several North American and a couple of Latin American stations that I would not have otherwise heard.

If you have a receiver with a built in programmable timer (e.g. SONY 2001D) you do not necessarily need a separate mains timer. It might be possible to activate the cassette recorder from the radio or if this is not directly practical an external unit called a VOX or voice activated switch might be the answer. This piece of equipment connects in the audio lead from radio to cassette and detects when audio starts i.e. when the internal timer has turned on the radio. It then switches on the recorder for as long as sound is present. So if you have the equipment but have not tried this before why not give it a go.

3.5 Interference

Interference is a topic that affects not just the MW DXer but just about every radio listener. In fact it is usually the level of interference rather than any other factor that limits the reception of weak and distant stations on the MW band.

Interference is usually taken to mean any unwanted signal (or noise) that, by adding to the desired signal, degrades reception of the wanted information. It is usually the case that the interference most often encountered on MW is man-made in origin. Whereas there is very little one can do about naturally occurring interference, it is possible, theoretically at least, to eliminate man-made sources of interference. The first step to suppressing interference is in fact recognising it and identifying its origin. Having identified a source of interference it is an unfortunate fact of life that it may prove impossible to do anything about it. The following are the most common forms of man-made interference to affect MW reception:

Co-channel interference:

Since the MW band is operated in a channelised manner and because there is only 1080kHz of available MW spectrum, there are inevitably several stations transmitting simultaneously on each channel. Normally the powers and locations of stations allocated to a particular frequency are chosen to ensure that a low level of co-channel interference occurs within the target area of each transmitter.

However, listeners outside the target area will experience this form of interference which generally gets worse at night as interfering signals propagate further via the "sky wave". In fact it is the acceptable limit of co-channel interference (also known as the protection ratio) that defines the target area boundary for a particular transmitter.

Modulation Splatter:

Splatter or adjacent channel interference can be recognised as unintelligible modulation or programmes heard mixed with the desired programme with the interfering signal originating from a station transmitting on a channel adjacent to that of the desired station. Given that stations are adhering to their local channel bandplan, there are two main causes of modulation splash. Firstly, splash can be the result of a station not limiting the bandwidth of its transmitted audio which results in components of the transmitted sidebands interfering with signals on adjacent channels; this form of splash can also result from a poorly maintained or over-modulated transmitter. Secondly a form of adjacent channel interference can be generated within a receiver with insufficient selectivity when receiving very strong signals. To test if adjacent channel interference is in fact receiver generated an aerial attenuator should be used to reduce the strength of the incoming signal; if the relative degree of interference reduces, a receiver effect should be suspected but if no change is observed then it is possible that the interference is actually being transmitted.

Heterodyne Interference:

A heterodyne is an audible beat note or whistle that is generated in a receiver when two signals on slightly different frequencies are received simultaneously. In a perfect world where all MW stations operated exactly on their allocated channels, heterodyne interference would not be a problem. However since different channel plans are used in different parts of the world it is possible to hear heterodynes on the MW band. Occasionally, within one radio planning region it is possible to find off channel stations either because the station has failed to conform with planning guidelines or a technical problem has arisen in the transmitter. In 1978 the frequencies of the European Asian and African channels were aligned to all be exact multiples of 9kHz, and every station was expected to retune their transmitter to the new channels. However quite a few African stations did not make the move and even today a number of off channel stations are audible. Their presence can cause heterodyne interference to other stations but the keen DXer can use the presence of a heterodyne tone as a good guide to a weak distant station. For example 1395kHz is an official channel used in Europe and Africa but Radio LomŽ in Togo never moved from the old frequency of 1394kHz. So if the listener is hunting LomŽ the presence of a strong heterodyne interfering with stations on 1395kHz indicates that the path to West Africa is open.

Unwanted heterodynes are annoying but fortunately they are easily removed with an audio notch filter. DXers often purchase such an accessory [see Section 6.2] since it improves reception and reduces listener fatigue.

Electrical Interference:

This title covers a multitude of interference sources which will tend to affect listeners living in built up areas, particularly near industrial zones. Man-made electrical interference comes in all shapes and sizes but can be classified as intermittent or long term. It can be difficult to track down intermittent sources of interference but fortunately their nuisance value is not long lasting.

Common examples are engine interference from the poorly suppressed spark plugs of passing cars, and arcing of electrical contacts in thermostats and switches. If the source is identified it is generally not too difficult to suppress this sort of interference. Other examples are caused by faulty street lights and faulty insulators on overhead power lines and in both these cases the solution is to inform the relevant authority. The longer lasting variety is commonly due to harmonic radiation from television (TV) and visual display unit (VDU) timebases. TV interference is audible as a rough buzzing located at precise intervals across the MW band of 15.625kHz (in Europe) or 15.750kHz (in N. America). VDU interference can appear with a frequency separation in the range of 14-18kHz. Unfortunately this form of interference often restricts any serious DXing to outside TV hours. Generally as more and more electrical equipment enters the home and office the greater the level of interference and the less chance there is of suppressing it. Among the more recent sources of (very potent) interference are computers and electronic telephones and office exchanges. Regrettably there is usually little a DXer can do cure this affliction unless they own the offending piece of equipment.

Jamming:

This is a deliberate attempt to interfere with reception and is usually a transmission of man-made noise intended to blanket another programme to make it unintelligible. The amount of jamming present tends to reflect the degree of political unrest in the world and today there is relatively little to bother the MW listener. The extensive jamming associated with Eastern Europe and the former USSR is now consigned to history, but jammers are still active in the Middle East and Korea.

Even if one lived in a world without any man-made interference, one would still notice a whole range of noises that limit reception of very weak signals. Of these the least significant (for the MW listener) is the thermal noise and other electrical noise components actually generated within the components of the receiver. This is because the level of other naturally occurring noise sources picked up by the receiver's aerial is many times greater. Common examples of these types of interference are atmospheric static, which manifests itself as a continuous crackling noise and lightning discharges which are heard as a loud crashing noise. The distinguishing feature of these signals is their broadband nature; namely the noise will be heard at all frequencies in the MW band although the intensity will decrease at higher frequencies. It is interesting to note that the radio wave emitted by a lightning flash behaves as any other radio wave and therefore can propagate over considerable distance; in fact one of the great sources of interference worldwide is the noise generated by the large numbers of daytime tropical thunderstorms. It is for this reason that many broadcasters in the tropics choose frequencies between 3 and 6MHz for local broadcasting where the effect of thunderstorms is much reduced.

4 The Next Step

4.1 Receivers

The choice of a receiver for MW use is nearly always a compromise between performance and price. Even if money were no object, finding a truly "no compromises" MW tuner is probably the "Holy Grail" of the hobby. Nowadays, however, there are some extremely good value for money receivers available that leave earlier generation units in the shade when it comes to features and price. That is not to say that a thirty year old valve receiver is no use, but older receivers lack some of the convenience features like digital frequency readout and memories.

For the DXer there has never been a better time to buy a new receiver than today since, like all things electronic, prices have fallen dramatically in real terms over the years. If we take stroll down memory lane to look at what a typical basic DXers receiver would have cost in Europe, as an example, we find;

1953         Eddystone 750;  Eleven valves       £68        (US$100)    
             R1155 ex Air Ministry; Ten valves   £12        (US$18)     
1964         Codar CR66; Six valves              £24        (US436)     
             HE30; Eight valves                  £41        (US$60)     
1968         Trio 9R59DE; Eight valves           £39        (US$60)     
1971         Eddystone EB35; transistors         £99        (US$150)    
             Eddystone EC10; transistors         £75        (US$110)    
1980         Yaesu FRG7; transistors             £199       (US$300)    
 

In 1994 the choice of receivers has never been wider and the DXer could pay anything up to a couple of thousand dollars (!) for a semi-professional unit. If sheer value for money is top of your list then there is probably not much around that will beat the Sangean ATS803A which isold by a number of dealers under different model numbers: e.g. as the Matsui MR4099 in the UK for under £100. This receiver is a portable with digital readout, synthesised tuning, no gaps tuning from 150-30000kHz, selectable bandwidth, BFO and signal meter. Actually the ATS803A, which was based on the more expensive Sony ICF2001, is built in Taiwan by Sangean. In the 14th edition of Radio Netherlands Receiver Shopping List, the radio was awarded ****, the joint highest rating awarded to a portable receiver.

What is a Communications Receiver?

Many listeners ask "what is a communications receiver and how do I chose one?". There is no simple definition of a communication receiver but often what sets such a device apart from an ordinary radio is its need for an external aerial as opposed to the internal ferrite rod or whip fitted to the majority of domestic units. For virtually all other forms of DX listening (such as short-wave or VHF) a specialised receiver will be needed, but fortunately for the MW enthusiast it is possible to get started with even the most basic of domestic receivers since they all tune the frequencies of interest i.e. 520kHz - 1605kHz. Using this sort of equipment it is possible to look for the weak signals that are found all the way down the dial between the strong locals, but after a while the newcomer to the MW band will start to appreciate the limitations of a basic domestic receiver and want something better. That is not to say that under the right conditions real DX cannot be heard on a simple receiver, but a communications receiver will make it a lot easier to hear. Why? Well there are several areas in which such a receiver is superior to its domestic cousin.

In the main a communications receiver is distinguished by its sensitivity, its selectivity and the accuracy of its frequency readout. Sensitivity is the measure of a receiver's ability to pickup and render audible weak signals. This is not so much a problem on MW since many stations use such vast transmitter powers. Furthermore the limit to weak signal reception is rarely the receiver itself since the background noise on the MW band due to atmospheric static and man-made electrical interference is so high. A good receiver will be sensitive but not overly so, since excessive sensitivity is often accompanied by the unwanted tendency to overload on strong signals.

The ability of a receiver to separate two radio signals on two different, but closely spaced, frequencies is termed its selectivity. This is a vital parameter if good MW performance is to be had from a receiver (domestic radios are usually very weak in this area) since the keen DXer will be trying to separate stations that may be as little as one or two kHz apart on the dial. This is very much the case if you are hunting transatlantic DX on split channel frequencies. A good communications receiver will have several different switch-selectable bandwidths ranging typically from 2 to 10kHz.

It is pointless for a receiver to be able to separate closely spaced signals unless the user is able to identify which frequency is being resolved. This is why most communications receivers will have accurate dials or frequency readouts; either mechanical scales or dials or the more modern digital frequency readout. Readout to 1kHz accuracy or better is highly desirable on MW.

To get started on the MW band with a communications receiver could set you back anywhere from £50 to £5000 depending on the sort of equipment chosen. Over the years hundreds of different receivers have been made, all with their pros and cons and to do them all justice would soon fill a book with detail. There are some general tips worth bearing in mind when choosing a receiver. Broadly speaking communications receivers have gone through three phases, namely the valve based units of the 1950s and 60s, the early solid state receivers of the 60s and early 70s and finally the transistorised receivers developed since about 1975. For the DXer on a budget the best bet is one of the receivers in the first category, some of which have justifiably become quite famous such as the RCA AR88D, Murphy B40, Marconi R1155 or the Eddystone, Hallicrafters or Hammarlund range of receivers. In general one can expect these units to be heavy and robust with good dials and very good reception on MW. If they have one limitation it is that they tend to run out of steam above 20MHz but this is of little concern to the MW DXer. Typically receivers of this class can be bought quite cheaply second-hand but you may end up paying more if you purchase 'professional' receivers from this era such as the Collins R390A, Drake R4, or the Racal RA17.

Quite often you will see receivers such as the Eddystone EB35 or EC10 or the Realistic DX-300 advertised quite cheaply second hand - steer clear of these as they represent the second category. A problem that afflicted the vast majority of early transistorised receivers was their susceptibility to overload. By the mid- seventies transistorised receiver designs were beginning to match the performance of the valved receivers of the fifties. OK they had all the extras such as digital readout, frequency synthesis and many other facilities to make the DXers life easier but in terms of true DX hunting ability they were still no better. The latest developments, since 1980 say, have almost entirely been driven by the Japanese companies (except for recent military equipment which probably won't be surplus for at least another decade!). Some of these receivers are ideal for the serious MW DXer (e.g. Icom R71 or NRD525) but be prepared to part with the sort of cash that would buy a second hand car!

One parameter which has often been overlooked in the design of receivers for the hobby market is their strong signal handling characteristics. This single characteristic actually is an amalgam of several underlying parameters such as reciprocal mixing due to oscillator noise, mixer intercept point and r.f and i.f filter performance. For the MW DXer good strong signal performance is probably the most important feature to look for when choosing a receiver.

Once you have a good receiver, you may well be tempted to improve it some way or other. Most commercial receivers are designed to a target price rather than an specification and often surprising improvements in performance can be realised for very little cost. The trick is knowing what to do and a good starting point is the experiences of other users of the same receiver. Many tips and enhancements have been published by DX clubs [see Section 6.1] in their journals.

Since 1985, when Sony introduced their ICF2001D/2010, there has been a growth in the number of communications receivers offering synchronous detection of AM signals. Simultaneously synchronous detectors as add-on modules have also proliferated. Conventional diode detectors used for AM reception for the best part of 70 years have several limitations. In particular they cannot handle signals suffering from the selective fading associated with signals arriving via sky-wave propagation paths. Synchronous detectors perform much better in this respect and therefore can produce much better quality audio. Certain designs of synchronous detector also allow the user to independently chose to listen to either the upper sideband or the lower sideband. Since both sidebands in an AM signal contain the same information they should both sound the same, however one sideband is usually less affected by interference than the other and so selectable sideband can be very valuable.

4.2 Antennas
DIY MW Loop Aerial

This is the commonest "specialist" antenna used by listeners to MW frequencies because it is usable indoors, readily home-built and low cost. The loop possesses a very predictable directional receiving pattern which allows signals from different transmitter locations to be selected by carfully rotating the antenna about its vertical axis. In addition most loops are designed to be resonant on MW frequencies and therefore are tunable. This is often a very valuable introduction of selectivity before signals even reach the receiver. A good loop tuned to 1MHz will easily reject most signals more than + or - 50kHz away from the desired frequency, thus virtually eliminating any images or 2nd order intermodulation products generated within the receiver.

There are numerous designs for loops. Some are tuned, others are broadband; some are compact indoor models, others are massive outdoor devices, but the commonest design is based on a 1m square wooden frame on which 7 turns of wire have been wound. This inductance is then parallel tuned by a variable capacitor with a maximum value of about 400-500pF. The loop is mounted on a base supported by a wooden broom handle which acts as its axis of rotation. For full constructional details of loops it is best to seek out some of the specialist publications listed in Section 5 since there is not enough room here to cover the construction in detail.

Figure 1 illustrates the all important directional pattern of the loop, which clearly exhibits two symmetrical nulls and peaks which can be directed to undesired or desired stations by physical rotation. In this way the loop is very capable of separating two or more co-frequency stations provided the signals are not arriving from the same (or directly opposite) directions. If the direction of arrival of two signals is separated by 60¡- 120¡ then the loop really excels.

DIY Beverage Aerials

The second key aerial, and probably the best, for MW listeners is the Beverage. This aerial is one of the simplest and oldest designs around, having been developed by Harold Beverage in the 1920s. In fact an aerial of this type, 12km long, was used by Beverage in 1922 for the reception in the USA of some of the first low frequency (approx 1.2 MHz) transmissions from Europe.

Figure 1: Directional properties of a Loop Antenna

For a Beverage to be reasonably effective it needs to be between 1 and 10 wavelengths long, which on the MW band implies lengths between 200 and 5000 metres. The longer it is relative to the wavelength of interest, the more directional the aerial becomes. Remember that a Beverage has its maximum signal pick-up along its length and that the aerial should point along the great circle path towards the desired reception area (Figure 2). The Beverage is even cheaper than the loop to build. It is a broadband antenna (i.e untuned) and so effective over the whole MW band, but by virtue of its size it always points in one direction. This means that its reception nulls cannot be easily targetted on unwanted signals. Professional receiving installations (with bigger budgets than DXers) often construct whole arrays of Beverage antennas radiating out like spokes on a wheel from the listening site. The radio monitor of course is able to chose the antenna which gives best quality reception.

Figure 2: Directional properties of a Beverage Antenna

Over the last half century considerable research into the Beverage has been conducted and detailed design rules exist but for the radio enthusiast this is one aerial design that is very tolerant of design imperfections. Here's what you need to do to put your own Beverage aerial together and to have a go:

Location: Unfortunately the Beverage is a large aerial but it doesn't really need much space and it can often be a "secret" aerial erected unobtrusively. Ideally you need to have a large field or woodland at the back of your house but a long straight fence can be used to support the wire. If you have lots of space you have the freedom to chose the beam direction but if you are just taking advantage of local geography then you may have to accept the limitations imposed on you. If you lack any significant space at home a good alternative is to find some open land nearby.

Wire: Hard-drawn copper wire is best for a permanent aerial since it won't break, but it is not cheap and is quite heavy. I tend to use 7/0.2mm multi-stranded insulated wire for temporary DX-pedition type aerials. A continuous barbed wire fence (galvanised steel) is OK also as long as it's not too rusty to make good electrical connections. If you want to put up a cheap and disguised aerial use thin transformer wire (eg 40 guage); you can lay this along a hedge row. Whatever wire you chose you'll need to be prepared for breaks and repairs; "chocolate block" connectors are very useful accessories when working with Beverages.

Supports: Gardeners-style bamboo canes (4-6 feet tall) are cheap and good for the job. Just cut a slit at one end with a penknife or junior hacksaw to hold the wire. Lightweight wire (eg 7/0.2mm) needs a support every 15metres or so. If a straight hedge-row or fence runs in the desired direction you can dispense with the bamboo canes; likewise it is possible to support wire in trees or bushes as long as a reasonably constant height (between 4 and 10 feet) above ground can be maintained.

Earth stake and terminating resistor: If a Beverage is operated just as a long wire it will be directional but will pick up signals from both ends of the wire but if the end of the wire furthest from the receiver and nearest the target reception area is terminated with a non-inductive (eg carbon) resistor equal in value to the aerial's characteristic impedance (usually about 500 - 600 ohms) the aerial becomes unidirectional. For best results it's good idea to experiment with the resistor value but even a fixed resistor of, say 560 ohms, connected between the aerial and the ground stake will do the job. One good way to produce the terminating resistor is to solder in series a dozen 1watt 47ohm resistorswhich are then encased in either heat-shrink plastic tubing or self-amalgamating tape. The use of many low value resistors makes the whole combination less prone to moisture affecting the total resistance value. Do not forget that for best results a good earth stake is needed at both ends of the aerial, one for the terminating resistor and the other for the receiver.

Receiver: If you aren't operating from a permanent home installation, or planning a full scale DX-pedition from, for example, a farmhouse, you'll need portable equipment. One good portable receiver that performs very well on the MW band is the Sony ICF2001D. This radio can run off its internal batteries but alternatively a communications receiver that runs off 12V could be used. To make the most of the 2001D (and many other receivers) it is usually essential to place an aerial tuning unit between the Beverage and the radio to avoid overload problems caused by strong local signals. Just imagine the simplicity of driving up to your aerial, parking in a lay-by off the road, and then all that you need to do is pass the aerial wire through the car window, connect it to the receiver and you are ready to go! With a bit of ingenuity you could be DXing with your very own Beverage aerial; you certainly don't need to own several acres of land.

In fact recently I erected a Beverage on a piece of waste land not far from my home. To find the location I did a little browsing of local maps and then surveyed the sites by driving around the neighbourhood. I guess I was lucky but I only had to visit four locations before I found an almost ideal site. Furthermore the site was derelict and deserted so I put up a 330metre run of wire through the bushes. The receiver end terminates on a fence post with some large nails to which I simply connect the receiver with crocodile clips. whilst at the other end I installed the terminating resistor between the aerial wire and a copper earth stake driven deep into soft earth in a ditch. In my case a good ATU is essential since I have a local MW transmitter on 1170kHz.

4.3 Propagation
Normal Propagation of MW signals

To make the most of MW listening you'll need to have a basic understanding of how a radio signal arrives at the receiver from a distant transmitter. A great deal of scientific work has been under-taken investigating the propagation of radio waves, but fortunately for the MW DXer things can be greatly simplified by considering just two dominant propagation modes. MW propagation takes place by means of two different and distinct mechanisms, namely groundwaves and skywaves.

GROUNDWAVES: The groundwave, as its name implies, travels along a path close to the earth's surface. How far such a signal goes is dependent on a number of factors, principally transmitter power, operating frequency and earth conductivity. Groundwave propagation is heavily dependent on the frequency, with low frequency signals travelling greater distances. In fact, every thing else being equal, groundwave signals from a station on 550kHz will travel twice as far over land as those radiated by a station on 1500kHz. The earth conductivity is also a very significant factor and it is found that the better the conductivity the further the signal travels. Sandy or rocky soil is the worst terrain whilst sea water is best and in regions such as the Caribbean, where the sea is particularly saline (and therefore more conductive), groundwave reception of stations up to 1000 miles distant is possible. In contrast, a similar signal travelling over rocky terrain would carry only about one quarter of this distance. Groundwave propagation is very stable resulting in consistent reception conditions. It is, however, usually only associated with daytime (although equally present at night) since at night long distant reception is predominantly via the sky wave. Because of its stable daytime behaviour, radio stations usually optimise their aerials to radiate as much of their signal as possible via the groundwave in order to improve coverage.

SKYWAVES: There exists a rarefied region of the earth's upper atmosphere that absorbs the intense solar ultra-violet radiation thereby protecting life on the earth's surface. This radiation results in a region of ionised gases known as the ionosphere, which, depending on diurnal and seasonal variations, consists of several fairly distinct layers of high ionisation (Fig. 1). These layers have a profound effect upon radio waves approaching them from transmitters on the ground below. Under certain conditions refraction of waves occurs, resulting in the "reflection" of signals back down to the earth, whilst at other times signals can be totally absorbed by the ionised gases. During daylight hours solar radiation penetrates the atmosphere far enough to form the lowest layer of ionisation, the 'D' layer roughly 60km above ground. The 'D' layer so completely absorbs signals on MW frequencies that any radio signals radiated by a station other than those parallel to the earth's surface are completely lost.

With the approach of sunset, however, the 'D' layer absorption decreases rapidly and within a few hours MW signals are being reflected back to the ground from higher regions of the ionosphere; depending on circumstances reflection occurs in the E region (about 100-120km up) or in the 'F' layer (225-300km).

Figure 3 & 4 illustrate this process and shows the skip distance which for MW frequencies turns out to be about 100 to 500 miles. Longer distance reception is possible when multiple reflections occur between the ionosphere and the earth's surface. This occurs with least signal loss over ocean paths hence the possibility of good reception of Brazilian stations here in Europe.

Figure 3: The Ionosphere and MW Propagation

Whilst the skywave enables good MW DX at night, it also leads to a deterioration in reception quality for the normal broadcast listener. Firstly there is a region about 50-100 miles from a transmitter (Figure 4) where the groundwave and the skywave signals are received with roughly equal (but varying) strength, leading to severe distortion. Additionally all skywave signals are affected by fading as a result of the continually changing characteristics of the ionosphere.

Figure 4: Skywave / Groundwave Interference
Anomalous Propagation

A previous section examined some of the basic factors governing MW (and LW) reception, in particular the effect of the ionosphere and the influence of solar radiation and ground effects. We deliberately restricted the subject to effects of a regular or predictable nature; the sort of parameters that a planner takes into account when planning the reception area for a new station.

There are however many other occurances that have a bearing on radio propagation at these frequencies; each with a greater or lesser degree of unpredictibility. Although it is nice to be able to predict when good DX will be heard on the MW band, it is the possibility of the unusual occurring that adds a touch of excitement to the DXing hobby. One of the overriding features of MW propagation is the effect of solar radiation on the upper regions of the earth's atmosphere. Predictable effects of solar radiation can be seen as diurnal and seasonal variations in MW propagation as well as in the influence of the 11 year sunspot cycle.

Less predictable events include ionosperic storms, shortwave fadeouts and polar disturbances. These somewhat esoteric events result from disturbances occurring in the sun, which is, under such circumstances, referred to as 'active'. The mechanisms behind such events are both complex and in some instances not yet fully understood but fortunately the average DXer is likely to be more interested in knowing the effect rather than the cause. In addition it could be very helpful to know when such an event was in progress and to be able to gauge its possible effect on DXing. A number of institutes around the world keep a watch on the sun and the ionosphere but the DXer is faced with the problem of obtaining (and interpreting) this extensive scientific information.

Fortunately the American National Bureau of Standards provides this information via the standard time and frequency broadcasts of station WWV. This station, which is most likely to be heard on 5.0, 10.0 or 15.0 MHz, transmits regularly up-dated radio propagation data during the 18th minute past every hour. It is also possible to obtain the same message by phoning a pre-recorded announcement: the US phone number is +1-303-497-3235.

One piece of information transmitted via WWV that is particularly interesting, is the Fredericksburg 'A' Index (more properly called the Fredericksburg Index of Geomagnetic Activity in the Earth's Magnetic Field) which can be used as a simple guide to propagation on the MW band. It is a simple matter to construct a daily graph of the A indices from which basic propagation predictions can be made. High values (above 20) indicate that MW signals in high latitude paths are likely to be absorbed, leaving signals propagating via paths closer to the equator to dominate. Low values over a period of time indicate a likelyhood of improved reception via higher latitude paths. Long periods of very low (6 or less) values are needed to raise the possibility of good high latitude reception throughout the entire MW band.

4.4 Make Reception Reports Really Work

If you are one of the many MW DXers who not only likes to hear a station but wants to collect a verification or QSL to "prove" that reception actually took place, then you'll appreciate that hearing the station in the first place is only half the problem. I'm sure that you've wondered why not every station replies to your letters or reception reports. Perhaps only around 50% of MW stations reply; what can be done to increase this ratio? Many MW broadcasters (in contrast to their SW counterparts) are not interested in audiences in far flung places since their double glazing advertiser is unlikely to extend his sales overseas!

Firstly imagine yourself in the position of the station engineer and then imagine you received a letter from a faraway listener asking for a QSL card. Could you be bothered to reply if you've already received a hundred similar items in your in-tray that week? I know of station engineers that have commented "... some of the reports we get are terrible..", "... we only now reply to reports containing IRCs as the postage was getting rather expensive..", and "... I always reply to DX reports but never know if my letters are received.."

What a listener needs to do is to convince the station that reception really took place and that the report is not just being made up. In addition you need to make the station's task in replying as simple as possible and it always helps to make your reception report stand out from the crowd so that perhaps it won't end up in the "round file". Try these 10 steps to good reception reports:

1) Convince the station: Include full details of commercials and public service announcements that you heard since virtually all stations record these details in their logs. Station slogans won't on their own convince anyone since they are often well-known and widely reported and also lists of records heard are not always very useful since details aren't always kept in station logs. Worst of all is something like "man talking.." or "music" which won't help convince anyone! The golden rule is the more detail the better.

2) Make their job easier: Use the station's local time in reception reports so that they don't have any tricky time zone conversions to do. The only exception is if the station is an international broadcaster that has been announcing a different time zone (e.g GMT or UTC) on air. It is often wise to note down the actual time announced in time checks rather than what your watch says since many stations have somewhat inaccurate studio clocks!

3) Make their job easier: Send return postage with your letter. Best of all include mint stamps from the station's country but since this is easier said than done you could send International Reply Coupons which are obtainable from the Post Office. Unfortunately some countries do not accept IRCs for exchange into local postage stamps. For the USA and many other countries you can instead send a US$1 bill since hard currency is often appreciated.

4) Make their job easier: Enclose a prepared sticky label with your return address already on it.

5) Make their job easier: Write in the station's natural language unless it is a big international broadcaster with various language departments. The natural language may not be the main language of the country they are in (e.g. Spanish speaking stations located in the USA).

6) Help the station: local MW stations don't need listeners thousands of miles away; certainly they don't attract more advertising because of this. So if you can help the station with constructive comment on programmes (what you liked and disliked) and on technical quality (eg modulation, audio quality or frequency stability) or by identifying interference, so much the better.

7) Make your letter stand out: BE POLITE and request a QSL card - never demand one.

8) Make your letter stand out: Introduce yourself and your location; maybe include a local picture postcard or some stickers from your local radio stations.

9) Make your letter stand out: use commemorative or unusual stamps on the envelope; there maybe a philatelist at the station. Unfortunately in some parts of the world this might also make your letter attractive to thieving hands in the postal system.

10) Make your letter stand out: Give a realistic and detailed decription of reception conditions in words that are not too technical (remember it's not always the engineer reading your letter). Never use SINPO style codes on their own.

If you follow some or all of these tips you should not only increase your chances of getting a reply from a station but you will help contribute to good relations between DXers and broadcasters. Finally, if you receive a reply from a station it is an often over-looked basic courtesy to thank them. It is simple and quick (and not too expensive) to send a postcard direct to whoever wrote from the station letting them know that their letter arrived safely and thanking them for their trouble. Research during a Radio Netherlands Media Network edition revealed that very few bother to say "thanks", and yet it makes all the difference.

5 Moving On

5.1 Specialist Clubs for MW/LW DXers


N America               Publication                 Contact Point                 
National Radio Club     DX News;  30 times per      DX News Subscription Centre,  
                        year                        Ron Musco, PO Box 118,        
                                                    Poquonock, CT 06064-0118,     
                                                    USA                           
International Radio     DX Monitor;  34 times per   11300 Magnolia #43,           
Club of America         year                        Riverside, CA 92505, USA      
Europe                                                                            
MW Circle               MW News;  10 times a year   Club Secretary, Harold        
                                                    Emblem, 137A Hampton Road,    
                                                    Southport, Lancs., PR8 5DY,   
                                                    England                       
Arctic Radio Club       mv-eko;  12(??) issues per  Box 5050, 350 05 Vaxjo,       
                        year                        Sweden                        
UmeΠKortvaggskubb      Distance;  16 issues per    Box 117, 90103 Umea, Sweden   
                        year                                                      
Oceania                                                                           
Australian Radio DX     Australian DX News          Box 227, Box Hill, Victoria   
Club                    (monthly)                   3128, Australia               
 


Most other radio clubs that concentrate on shortwave radio also include sections on Medium and Longwave listening. However not being specialists their coverage of this topic is generally not as comprehensive.

A good list of clubs can be found in the World Radio TV Handbook (pages 59-62 in the 1995 Edition). The following are only a small selection of established clubs with regular publications containing good MW/LW columns:

Europe:
  • British DX Club;126 Bargery Rd, Catford London SE6 2LR, England
  • World DX Club; 17 Motspur Drive, Northampton NN2 6LY, England
  • Play DX; via Davanzati 8, 20158 Milano, Italy

N America:

  • Ontario DX Association; Box 161, station A, Willowdale, Ontario M2N 5S8, Canada

S America:

  • Conexion; Casilla de Correo 465, 1900 La Plata, Argentina
  • The Radio News; PO Box 3551, El Trigal, Valencia 2002, Edo. Carabobo, Venezuela

Africa:

S African DX Club; PO Box 72620, Lynnwood Ridge, Transvaal 0040, S. Africa
5.2 Sources of Equipment

Audio Accessories

Datong             Switched capacitor  Clayton Wood Close,      +44-532-744822      
Electronics Ltd.   noise and tone      West Park, Leeds LS16                        
                   filters             6QE, UK                                      
JSP                DSP noise and tone  Box 97757, Rayleigh, NC  +1-919790-1011      
Communications     filters             27624-7757, USA                              
Inc                                                                                 
I-Com.             DSP noise and tone  793 Canning Parkway,     +1-716-924-0422     
                   filters             Victor, NY 14564, USA                        
 

Antennas

Kiwa Electronics   large air cored     612 South 14th Avenue,   +1-509-453-5492      
                   loops               Yakima WA 98902, USA     or 1-800-398-1146    
                                                                free                 
Graham Maynard     large air cored     16 Woodford Avenue,                           
                   loops, outdoor      Newtownabbey, N Ireland                       
                   designs and         BT36 6TL, UK                                  
                   phasing units                                                     
Palomar Engineers  ferrite cored       PO Box 462222,           +1-619-747-3343      
                   small loops         Escondido CA92046, USA                        
 

Receivers

Hundreds of models are widely available new and secondhand so I will only list receiver types that are particularly popular with top MW DXers, selected primarily for good performance with MW AM signals.

  • Collins (or Motorola) R390A/URR (only second-hand, ex-military; rare; valves, heavy)
  • Lowe HF225 Europa (upgraded basic HF225, current product) [optional synchronous AM]
  • Sony ICF2001D/2010 (current product) [synchronous AM is standard]
  • JRC NRD535 (current product) [phase locked ECSS fitted]
  • JRC NRD525 (second-hand) [synchronous AM accessory needed]
  • Drake R7A (second-hand) [synchronous AM accessory needed]

5.3 Bibliography


Books you must have   Author         Publisher, date;    Notes                     
                                     ISBN                                          
World Radio TV        Editor: A.G.   Billboard           Good for MW but limited   
Handbook              Sennitt        Books.1995 49th     USA coverage;  600+pages  
                                     edition.            annual                    
                                     ISBN 0-8230-5926-X                            
Recommended Books                                                                  
MW; A Practical       Graham         MW Circle 1988      22pp                      
Approach              Maynard                                                      
Getting Started in                   National Radio                                
MW DX-ing                            Club 1987                                     
Antenna File Vol. 1   various        MW Circle 1993      26pp                      
Receiver Shopping     Jonathan       Radio Netherlands   Regular publication;      
List                  Marks et  al.                      back issues also very     
                                                         useful                    
The Wave Antenna for  Walter J       Wilhelm Herbst      36pp                      
Reception of Medium   Schulz         Verlag, Kšln. 1985                            
and Long Wave                        ISBN 3-923 925                                
                                     10-7                                          
WRTH Equipment        Jonathan       ISBN 0-8230-5949-9  Receivers, antennas,      
Buyers Guide 1993     Marks Willem   (new edition due    software etc.             
edition               Bos            mid-1995)                                     
The Beverage Antenna  Victor A       Misek;  Hudson NH   39 pages very good,       
Handbook              Misek          03051, USA 1977     maybe out of print        
Receiver File Vol.1   various        MW Circle 1993      Modifications & tips by   
                                                         experts                   
Proceedings           various        Fine Tuning, c/o    Excellent compedium of    
                                     John Bryant, RRT#5  articles on receivers,    
                                     Box 14,             antennas, and features    
                                     Stillwater, OK      written by experts; each  
                                     74074, USA          issue is completely       
                                                         different (biennial)      
DXers Technical                      IRCA; 2nd Edition   120pp                     
Guide                                1983                                          
Recommended but with regional bias                                                 
NRC AM Radio Log                     NRC (annual) 15th   Most comprehensive list   
                                     Edition in 1994     of all US & Canada MW     
                                                         stations; annually        
                                                         updated 440pages          
99 Nights on MW       Wilhelm        Wilhelm Herbst      European                  
                      Herbst Verlag  Verlag              Good introduction to MW   
                                     ISBN 3-923          DXing                     
                                     925-04-2                                      
Dial-Search 1992/94   George Wilcox  G. Wilcox, 9        UK/Europe (biennial)      
                                     Thurrock Close,     48pp + maps               
                                     Eastbourne, BN20    ISBN 0-9508575-5-6        
                                     9NF, England                                  
                                     7th Edition; 1992                             
MW Guide to Asia,                    Australian Radio    Oceania                   
Australia & the                      DX Club                                       
Pacific                                                                            
IRCA AM-FM Almanac                   IRCA  5th Edition   General station/network   
                                     1991                data; USA + some Canada   
                                                         200+ pages                
 



Books to Avoid                                                                     
Whites Radio Log                     Worldwide           136 page three way list   
                                     Publications In.,   of all MW, FM and TV      
                                     P.O Box 5206,       stations in Canada &      
                                     North Branch NJ     USA; BADLY OUT OF DATE    
                                     08876 USA                                     
 


NB: There are many books that contain listings and information about stations, their frequencies and programme schedules. Although the rate of change of MW stations is less than on shortwave (where frequencies are often changed several times a year) books can rapidly become out of date. Those published annually are the best and even these rely on quarterly update bulletins to maintain a reasonable degree of accuracy.

Copyright notice: This publication is copyright and may not be copied without permission. Publications wishing to reproduce sections of this medium wave guide should contact us at

Radio Netherlands

attn: Jonathan Marks

P.O. Box 222,

1200 JG Hilversum,

The Netherlands .

FAX: +31 35 724352

© April 1994 Steve Whitt 4 Radio Netherlands. Updated April 1995

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