Enthusiast Page.

On this page we are offering advice for the beginner and aviation enthusiast who wishes to know more about listening to aircraft transmissions. Look at the bottom of the page for more information as to how to improve the listening performance on your scanner. We have split the information into several sections:

1) Airband advice.
2) Buying your first radio.
3) Selecting an antenna.
4) Advice on "Real time Radar" Systems

If you do not find the information you want, feel free to e-mail Ken at kencothliff@airsupply.co.uk or click on the "contact us" button.

1) Airband Advice for Listening Enthusiasts.

This advice is for those using airband radios and scanners to listen to the airwaves. Airband scanners can add a whole new dimension to visits to airports and air shows, and the airband radio will allow you to listen to frequencies throughout the world of aviation.

Aircraft radio frequencies throughout the world are normally based on the standard of 25kHz spacing between frequencies, but in recent years there has been a move to introduce spacing of 8.33kHz to allow for the 'freeing' of more frequencies to be available. At the time of writing this text, this is not yet widespread in the UK, but there is the chance of those frequencies being introduced as more aircraft are fitted with radios that can operate in those bands. Many airband scanners now incorporate the new 8.33 kHz step. Presently the Military have shown no interest in 8.33kHz spacing whatsoever. Also note that if you choose a scanner on which the 'Mode' can be varied - all aircraft radios operate in amplitude modulation - AM Mode.

REMEMBER: LISTENING TO AIRCRAFT FREQUENCIES IS ILLEGAL, owning and using a scanner is not.

Airband scanners vary in functionality and ultimately cost, with the ones at the cheaper end of the scale being less accurate and harder to tune to specific aircraft, approach and tower frequencies than the more expensive scanners. If you are unable to tune your scanner to specific frequencies you will find it much harder to hear operational frequencies and therefore more difficult to spot aircraft registrations and become a true spotter.

Airports and airshows are probably the best places to use your airband scanner. Busy airports are good because they have tower frequencies (which can be a regional control tower or international control tower) and approach frequencies, frequencies from air traffic control as well as aircraft frequencies from planes taking off. Airports can be an aircraft registration spotter's paradise.

WARNING: Always check airport bylaws before taking a radio onto Airport property as authorisation may be required. Listening to certain frequencies requires a licence.

What you can hear, and in turn relate to aircraft you see flying overhead obviously depends on the position of your location relative to airports and air lanes. Since VHF radio waves follow approximate lines of sight, the higher the aircraft, the farther away you can hear the messages from it. Transmitter power is also a factor, but generally speaking, high flying aircraft can be received up to 200 miles away. As a rule of thumb, frequencies below 123MHz are allocated to Air Traffic Control Centres (ATCCs) these can have regional control or control over a wider area although there are now many exceptions to this.

Some scanners also receive short wave aircraft frequencies as well as those on UHF and VHF aircraft bands. This short wave listening is not restricted to short range transmission like the other frequencies so you could find yourself listening to short wave transmissions from the other side of the world.

Ground stations may be screened by hills, buildings and other obstructions, so you may not be able to pick up the replies from a tower or approach unit if you live more than 10 miles away from it. The coverage for the ATCCs at London and Prestwick and the Sub Centre at Manchester is very much better, however there are a few places in the flatter parts of the British Isles out of range of one or more of the powerful transmitters. This is because they are sited some distance from their associated ground stations, usually on high ground. There may, however, may be some blind spots in reception for no apparent reason. The first thing to do is establish which ground stations are within range and which can help you identify aircraft flying in your local area. If you are fortunate to own a scanning receiver, you can set up the appropriate frequencies and monitor them when required. With experience, you will soon know which station an aircraft is likely to be 'working' : its height being a good clue as to whether it is talking to the local airfield, ATCC, radar unit etc. Unfortunately, in an area such as the Midlands there are so many ATCC units capable of giving a radar service that it may be difficult to discover to which a transit aircraft is talking. A flight on air lanes or airline routes in the South Midlands, for example, might be in contact with regional control in Bristol, Bedford or Brize Norton Radar Units or simply the London Flight Information frequency. Of course, the pilot may not be talking to anyone, nor does he need to if he keeps clear of aerodrome traffic zones and other restricted airspace.

Airband scanner users will find that there are two main types of airspace controlled and uncontrolled. When listening to aircraft frequencies you will find that listening to controlling airspace will offer more operational frequencies as this is where radio contact is mandatory. These controlled airspaces can be scattered all over the airspace and can be controlled regionally and nationally but are likely to be found near airports with busy air lanes and airline routes where planes approaching planes and planes taking off create an overcrowded airspace.

Airports with a control tower are known as controlling airports and it is here that you will find a good mix of tower frequencies and approach frequencies to listen to. Approach frequencies are used to line up approaching aircraft in the air lanes on airline routes.

These areas of airspace can be aircraft frequency hotspots where aircraft registration spotters could be kept very busy.

If you have the good fortune to live beneath an airway or airline route, and even better, close to one of its reporting points, the relevant airway's frequency can be selected and you can sit back and wait for something interesting to appear. Alas, rare aircraft seem to have a tendency to fly over when there is a solid cloud layer and only a tantalising droning rumble can be heard. Unfortunately, it is not just a simple case of listening in, running outside at the right moment and filling in one's notebook. Aircraft do not always use their registrations or serial numbers as call signs; the trend in commercial flying is for more and more companies to use a callsign totally unrelated to what is painted underneath the aircraft. The airlines have been doing this for years, but the practice has now spread to even taxi aircraft. Useful books on these are the annual editions of "Flight Routings" for civil and "Callsign" for military and civil.

The answers to any questions arising from this practice for the most part are to be found in the network of enthusiasts' magazines which keep most airfields under surveillance and publish detailed lists of visitors, usually tabulated by callsign as well as registration letters. The information is normally acquired by courtesy of the airport management or ATC, the ranks of which are riddled with enthusiast 'moles'. Some private airfields such as those run by British Aerospace, which operate military aircraft are understandably less cooperative, but there is often a local spotter who makes notes and passes them on. Since most trans-Atlantic flights from north-west Europe have to cross Britain at some point, even those anonymous airliners on contrails can be identified as there are several publications available which match the callsign and the registration of most of them.

Identifying military aircraft is very difficult as few use the actual serial number; USAF Transports being one of the few exceptions. Military aircraft generally use the UHF frequencies to talk to their own aircraft, but UHF receivers, hitherto unobtainable, are now commonplace. Unfortunately, the call signs of first line aircraft are changed frequently for security reasons.

Bearing in mind that air traffic has its rush hours too, certain times of the day can be particularly rewarding for airband listeners. For example, the Heathrow peak period for arriving traffic is mid morning, reflected in the increased landing fees at this time. Late afternoon, particularly on Fridays, sees an even larger volume of traffic in the congested United Kingdom airways system as the entire British Executive fleet seems intent on making for home.

For insomniacs, there is plenty going on even in the smallest hours of the night as aircraft flying the mail, wend their way towards Liverpool and East Midlands five nights a week from all points of the compass and fan out again some time later. Heathrow has a virtual ban on traffic after midnight because of noise restrictions; but Luton, Manchester, Glasgow and others send load after load of holiday makers to the Mediterranean and beyond, particularly on summer weekends. Mixed in are the cargo traffic, most of them scheduled, but occasionally including an extra service rushing some urgently needed parts for the motor industry.

High in the wide blue skies flies an aeroplane. Even in this endless expanse, there are invisible flight paths, along which aircraft are controlled for safety. This supervision of the sky highways is handled by the Air Traffic Service. From the cockpit, the pilot communicates with air traffic controllers on the ground for information to fly the aircraft.

This critical exchange of messages can be received moment to moment via the airband.

Some Short Wave (SW) frequencies between 2.85 & 18MHz and between 118 & 137MHz on VHF frequencies are generally assigned to the airband. Your receiver may monitor the SW frequencies used by international flights to communicate with overseas control centres as well as the VHF frequencies used between airports and domestic civil aircraft.

With your Air Supply receiver, you can experience the excitement of the cockpit.

AIRBAND LISTENING AND THE LAW : Legally there is no question about it. AIRBAND LISTENING IS AGAINST THE LAW. We understand that listening to airband does require a licence. However, persons are allowed to listen to such transmissions providing any information heard is not passed to a third party. Many of the scanners we sell can be tuned to the Police band and you are warned.

LISTENING TO THE POLICE AND CARPHONE BANDS IS NOT PERMITTED. ANYONE FOUND WITH SUCH FREQUENCIES IS LIABLE TO PROSECUTION AND SCANNERS CONFISCATED. YOU HAVE BEEN WARNED!

CLEARANCE (Air Traffic Clearance) : Instructions for the flight route, altitude and other necessary items must be received by an aircraft in order to take off. Airports do not assigned clearance frequencies, clearance is done by ground control.

GROUND (Ground Control) : Motion of aircraft and all vehicles in areas of the airport other than the runways are controlled by the Ground. Clearance to taxi towards the runways for departure or to a parking spot is also given by the Ground.

TOWER (Tower Control) : The main role in aerodrome control service is executed by the Tower who operate on tower frequencies. The clearance for approach and departure (taking off), and the control of all traffic near the airport (within a radius of 9km) are relayed by the tower. No aircraft can take off without clearance from the Tower.

DEPARTURE CONTROL: After the aircraft takeoff is verified visually, guidance is transferred to Radar Control. The function of Departure Control is to guide an aircraft into the airway which is an aerial highway. If the aircraft makes a sudden entry into the airway before reaching its assigned altitude, it may be on a collision course with other airborne vehicles. For this reason, all airports provide transition routes which are similar to the acceleration lane on a motorway. When the aircraft reaches the required altitude, guidance is transferred to the Area Control Centre (ACC).

AREA CONTROL CENTRE: An aircraft which moves beyond the range of the airport is guided by the nearest ACC. The ACC monitors the aircraft by radar to see if it is flying at the correct altitude and on the prescribed route. More than the required distance (Separation) is maintained between an aircraft and the aircraft flying before or after it on the same airway. This is done by ACC to avoid dangers such as near-miss accidents.

When it is necessary to change the route or altitude during flight, the pilot is required to ask for clearance from the ACC. Due to the development of the Automatic Pilot and other sophisticated devices for the aircraft, many pilots request a direct course to the destination without using the airway. The main role of the ACC is to adjust the distance between aircraft.

When the aircraft approaches the destination airport, it must gradually descend from its altitude. ACC guides the aircraft to its landing approach while maintaining distances from other aircraft and transfers control to Approach, which the destination airport's radar.

Small or mid-sized airports not equipped with radar depend on ACC radar for the aircraft to be guided to the low altitude zones of these airports. In such cases, the ATC and ACC issues the approach clearance (known as 'permission to start approach")

APPROACH CONTROL: When the aircraft starts descent, guidance control is transferred from ACC to the airport's Radar Approach Control. Approach Control guides the aircraft by radar towards the runway. The approach course is changed everyday according to wind direction, and this is interesting to listen to. If you tune in to the approach frequencies of big city airports during rush hours, this affords uninterrupted listening pleasure for hours. It gives you a real understanding of the dilemmas experienced by air traffic controllers.

TOWER GROUND: The aircraft guided by Approach to the runway is transferred to the Control Tower. Here, the landing clearance is requested. After the aircraft touches down, the Tower frequency is changed to the Ground frequency which guides the aircraft to is parking spot. The flight is now complete!

There may be some differences depending on the size of the airport or the existence (or lack of it!) of radar facilities, but the basic air traffic control flow has been explained.

Besides the above, departing and arriving aircraft information can be obtained over the airways from the Automatic Terminal Information Service (ATIS). ATIS in some airports is broadcast by tape recordings. The ATIS Information is generally updated every 30 minutes. The ATIS covers almost the same worldwide :

1. Airport Name;

2. Runway to be used and approach method;

3. Atmosphere phenomena, wind direction, wind speed, visibility, weather, cloud conditions, temperature, dew-point, altimeter sub-scale setting (Sea Level Atmospheric Pressure = QNH);

4. Any additional items.

The meteorological broadcasts provide information about weather, visibility, temperature, wind direction and wind speed from major airports to aircraft in flight. There are many VOLMET stations in the world. For example, the Shanwick VOLMET station broadcasts every 30 minutes (at hr:10 and hr:40) on the following frequencies : 3413KHz, 5505KHz and 8957KHz. SW and 13.264 MH2 SSB (LSB) mode are also used.

2) Choosing your first Airband radio.

First of all we have a responsibility to remind you that listening to air band transmissions is illegal; however the Authorities here in the UK to tend to ‘turn a blind eye’ to what most people regard a harmless hobby that brings much enjoyment to many people. For the sake of all listening enthusiasts we ask you to act sensibly especially when on Airport Property – use an earphone and don’t discuss the transmissions you hear.

 

We are often asked what is the best radio to buy. This mostly depends on what the user wants to listen to and the budget you have in mind. This section is designed to help the first time buyer come to a decision.

 

There are basically two types of radio on the market – the air band “receiver” and the air band “scanning receiver” – more regularly abbreviated to ‘scanner’. The difference between the two types of set is the ability of the scanner to memorise a considerable number of frequencies within the internal processor memory of the set, scan them and broadcast the voice transmission as it is received. The receiver will only broadcast one frequency at a time, and then has to be tuned to a second frequency to hear the alternative conversation. An analogue type receiver such as the “Multiband” or “Aircontrol M8”, has a dial tuner and no memory; it is the most basic type of Air Band radio.

 

However some of the newer receivers do have preset memory ‘pre-sets’ which enable a few frequencies to be pre-stored, and be brought into action by pushing the appropriate button on the dashboard of the set. Those type of sets, such as the Steepletone SAB2006, are the “halfway” stage between the analogue tuner type of receiver and the scanner. All the basic receivers will listen to Civil Air Band only – voice transmissions between 108.00 and 135.975 Mhz.

 

For the listener who is serious about their hobby, then the scanner is the answer; its ability to store frequencies in a logical order considerably increases the efficiency of the set and aids the user to plan the storage and use of those frequencies. In addition to the facility to listen to Military air band frequencies on some models (225 to 390.Mhz.), scanners come in two basic types. The ‘direct key entry’ type with conventional alphanumeric keypad, and the more recent ‘menu’ driven type with fewer buttons and employing cell-phone technology. We will not go into detail on each of the types here; that would take too much time, suffice to say that you should be familiar with the workings of a Computer, or mobile cell-phone and ‘texting’ to use the smaller sets such as the Maycom, or Alinco DJ-X3/7, and Icom IC-R5. Generally the ‘keypad’ sets are much more user-friendly.

 

Most scanners, though not all, store their frequencies in ‘channels’ and ‘banks’. The analogy here that we use to explain the storage system is to think of the banks as the ‘filing drawers’ in a cabinet, and the channels as ‘files’ within the drawers. Depending on the number of channels in the memory, and the ‘bank’ system of the set, the user can store the frequencies is his or her personal filing system, according to type, range or geographical locality. Remember the more organised you are the more efficiently the scanner will perform for you.

 

There is now the ‘budget’ to consider. As a rule, the more you spend the better the “buy package”. The more expensive sets generally include batteries or a battery pack, and other accessories. The cheaper sets usually only have the set itself, priced to keep the price as low as possible. A good option to include when purchasing is a protective case that will help protect your set, and there are many any other accessories to improve the set’s performance.

 

A further word of advice; BEWARE Transceivers, if buying from an unknown source, especially second-hand. These are air band radios that transmit, as well as receive and are intended for use by pilots who have a CAA radio licence and are thereby authorised to use them. Using one of these without a licence WILL lead to prosecution in the strongest terms.

 

We hope this advice will help you to come to a decision on the type of set you wish to buy.  We at Air Supply pride ourselves on our knowledge of air band radios so do feel free to telephone us at any time for more assistance. There is more advice on this section of the web-site about buying an aerial to improve the performance of your set. 
 

3) Selecting the best antenna.

More than anything else, we at Air Supply get asked for advice on the best aerial to use on a scanner. There is one simple reply to this, “Get a good one and put it up as high as you can!” That might be flippant but it’s the truth. The problem is for many people there are the financial implications to consider, as well as the practicalities. There is more “rubbish” talked about aerials than anything we sell.

Whatever aerial you choose, the most important consideration is the geography of your location; hills, buildings and even the curvature of the earth will have an affect of what you can listen to. Aircraft are easy, because they are up in the sky, but don’t be surprised if you can’t hear the ground controllers. If they are the other side of a hill you never will. Barometric pressure can make a difference too – usually, though not always, the higher the pressure the better the reception

Most scanners, though not all, are supplied with a rubber-cased ‘helical’ antenna, often known as a “rubber duck”. This is a practical aerial, easy to use especially when out and about, but for better reception, especially at home or in the garden, away from your local airfield, a telescopic antenna will give a better performance, and this can be adjusted in length to get the best result. REMEMBER – to pull it all the way out is NOT necessarily the best for performance. As a rough indication, about 21” (533mm) is the best for air band (118-137mHz.). The higher the frequency, the shorter the aerial needs to be; the lower the frequency the longer the aerial, which is why Citizen Band radio aerials (27mHz.) are always about 38-40” long. Some telescopics have a “Coil” built into the base of the aerial, so there may be adjustment required.

When using the scanner in the car, a “Magmount” or window mounted aerial is needed to bring the signal within the metal body of the vehicle. There are several types here for receiving different ranges of signals, from the standard type with a 3½ ” (90mm) magnet to the new “Micro-Magnet” types which are ideal for the person not wishing to keep the aerial on the car permanently.

The best performance of all will come from a base aerial mounted on the roof, or in the loft of your home. Again remember - the higher the better, so outside is always better than in the loft, though often the latter is the only possibility. There are several types here that can be split up into different specifications.

The white “Pole type”, with the aerial inside a plastic casing, the least obtrusive type, and dedicated to the frequency you want.

The “Discone type” – looking rather like a ‘naked’ umbrella – usually with a wide band reception range. Visually very prominent, and subject to the vagaries of the weather. (Note – always buy a stainless steel version if you live within 5 miles of the coastline.)
The “Yagi” directional type, similar to the widely used TV aerials one sees around. Good for picking up a specific distant ‘target’ such as an airport, but useless for “omni directional” or all-round listening like the other two.
Finally there is just an opportunity, to mention the “portable” base aerials. The ‘Nomad’ range of antennas allow the user to have the advantage of almost the performance of a base aerial, but portable for use on holiday or in the garden, shed or conservatory. We often sell this type of aerial to flat owners or tenants who are not able to use a fixed aerial. Just tie the aerial up top a high point and away you go – these are available in three different types as shown in our on-line shop.

Now proceed to the shop to select the aerial of your choice, or contact us for more detailed advice. Order items online.

4) Information for "Radar" Enthusiasts.

Whatever aircraft you listen to there is always some doubt as to where it is located. The new PC based systems, the Kinetic SBS1e and the AirNav Radar Box, now add another new dimension to the hobby of aircraft spotting. These systems use the information transmitted on 1090 mHz by the transponder in the aircraft that helps Air Traffic Control identify the aircraft on their screen. This radio transmission is received by a specialist receiver and interpreted by a programme onto a computer screen. As you can see from the photograph taken of our lap-top in the shop, this produces a really effective 'synthetic' radar picture. The scale of radius of the information is easily adjusted, and a second screen can be brought up which indicates the height of the various targets. In addition the track of the aircraft through the airspace can be shown, and colouring on the track indicates whether the aircraft is level, climbing, or descending.

There are now two quite different systems, The 'Kinetic SBS-1e' illustrated above in photos taken from our shop PC, or the later 'Air Nav Radar Box'. Both systems now use a small radio receiver (slightly bigger than a pack of playing cards), with SMA aerial connection. There is not sufficient time to detail all the differences, but one of the main ones is that the AirNav can be networked with other operators around the world, to pick up action at many other airports around the globe. The later version of the SBS (the "e" vervsion), now has an internet module built in also enabling connection to the internet. MY opinion is that the SBS-1 has a clearer screen, but the Air Nav  gives more information to each reading on the screen, with added information such as ICAO designators for the flight in question, and aircraft registration, if the transponder on the aircraft is send out that much detail. The AirNav has better visual definition of the screen readings as, opposed to the SBS, they move apart, as the aircraft position indicators close up on the screen. The AirNav also puts up a photograph of the target aircraft, taken from the database on the disc supplied. This can be updated by subscription.

Each has an information screen, nominally on the right of the main screen, (position can be changed) that can be quickly brought up, which can add more detail on the aircraft being tracked when highlighted as you can see on the second picture. This screen also  adds extra infomation on the aicraft, including Flight number and nationality flag. This part of these systems is really a 'Pandora's Box' of information. Both can be linked via the Internet to various information sites - a good one is that run by the Gatwick Aviation Society - which can add even more detail, such as the aircraft's history, construction details, and even a photograph of the aircraft in question, if it is on record. In addition such web-sites as these can also add to the screen more information such as topography and the various reporting points on the air lanes. It really depends on the size of your computer screen as to how much information it can collect, bearing in mind the definition required for the viewer. 

Finally, like most radio receivers, the performance depends the aerial. A Magmount aerial is supplied with the set, but if you are going to use the system in a downstairs room of your house or flat an outdoor aerial with a good quality low-loss cable, such as Westflex W301, is vital to get the best range. A Discone, or other wide band aerial, just WILL NOT DO! We at Air Supply have worked with one of our suppliers to offer a specialised aerial and less cost that that recommended by the manufacturer. However the correct cable could still cost a budget about £50.00, depending on cable length for this.

When used in conjunction with your scanner, "Real Time Radar" systems add a whole new dimension to the hobby of Aircraft spotting and Air Band listening.

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