Friday 7 August, 2009, 09:31 - Radio RandomnessAugust is almost universally, the world over, the month when schools are out and people head off on their well deserved and hard earned summer vacations. However, here at Wireless Waffle have received a number of worried e-mails from radio lovers who are concerned that whilst they are away on holiday they will not be able to enjoy listening to their favourite short-wave radio transmissions, whether the news on their favourite international broadcaster or the messages from their friendly neighbourhood secret service spy numbers station.
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Being equally worried, we have been searching for an answer to this annual seasonal dilemma and think that we have stumbled across the perfect solution. Study, if you will, the picture on the right. This is one of the Royal Air Force's fabled Harrier Jump Jets. If you look closely you will notice that strung from the rear tail-fin to a point just behind the pilot's cabin on the fuselage is a thin wire antenna. Normally this wire is too thin to be seen in such a small picture but we have enhanced it to make it more visible. This is an HF (a.k.a. short-wave) antenna which is used for air to ground communication. Similarly strung aerials can be found on civil aircraft and on many warships, stretching from the top of the radar tower to somewhere close to the deck.
These antennas actually work quite well and though a decent antenna tuner is needed to provide a good match at the range of frequencies on which military HF communications normally take place, they produce relatively good results because:
* the sloping nature of the antenna offers a degree of mixed polarisation, increasing received and transmitted signal strengths compared to a horizontal or vertical antenna (as with an inverted-V antenna)
* the position of the antenna above the body of the aircraft means that the aircraft acts as a reflector, directing signals upwards towards the ionosphere
* the antenna can be reconfigured to use part of the aircraft body to form a loop antenna where this is more effective
In a flash of inspiration, the Wireless Waffle team realised that a very similar antenna could be constructed and tied to a tree on a Caribbean island. However, though a practical and realisable solution, this idea failed to address some of the main difficulties in a number of very important ways:
1. not all holiday makers carry a roll of suitable wire
2. not all Caribbean beaches have a suitable tree on which to string an antenna
3. where trees exist, the holiday makers with wire may not be able to climb the tree
4. not all summer holidays take place in the Caribbean
Deflated but still keen to find a way forward, the team decanted to the local travel agency to study holiday brochures for alternative antenna mounts. Whilst wandering down the high street, one of the team happened to glance into a sports shop and inspiration struck: what if a suitable antenna could be built into an item of beach apparel such that it went on hoilday with the person concerned without needing to carry wires or tree climbing apparatus.
After much development, we are therefore very proud to present the 'Wireless Waffle Super Signal Holiday HF Antenna Apparel' (we are still working on a snappier title). In the same vein as the aircraft HF antenna, the wire is strung between the tail-fin of the wearer and a point below the fuselage where their head joins their body. As you will see, it bears a remarkable similarity to the one mounted on the Harrier Jump Jet.
Our thorough tests have shown that the antenna works exceptionally well and is very good at picking up signals. We managed to receive a strong Voice from America (saying something about a drink at the bar), whistles from the military and several numbers. Encouraged by these results, we are currently in discussion with a major radio manufacturer about the sales opportunities for our device and the outlook seems quite positive. Keep an eye open on beaches in your area and please send us pictures of any devices you find in use. If we receive enough we'll post a gallery so that others can see how to assure maximum performance.
Thursday 23 July, 2009, 08:00 - Radio RandomnessIt may come as a surprise to the more ICT literate that in this day and age, short-wave radio is still being used for secret communications from various security organisations to their field agents. No encrypted e-mails or messages hidden on web-pages, no images hidden in jpeg files or microdots or secret domain extensions. Nope, many agencies transmit messages over short-wave using standard AM modulation which can be received on every day, off-the-shelf radios.
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You may have even heard these transmissions and not known what they were. Known as 'numbers stations', the transmissions consist of a series of numbers being read out in a mechanical fashion, often repeated several times and often preceded by a specific piece of music. The numbers are usually in English, German, Spanish, Arabic or a slavic language (eg Russian) which may give an indication of the source of the signals (though it is known, for example, that some of the transmissions in English are from the Israeli secret service, Mossad).
Unlike most short-wave transmissions, the source of these signals is often elusive and as such, receiving any kind of acknowledgement of their reception is nigh on impossible. This does not stop, though, a band of enthusiasts monitoring and recording these signals and exchanging information between likeminded individuals. Probably the largest such group is known as 'Enigma 2000' who publish a regular monthly newsletter which can, thankfully, be obtained for those who are interested without the need to join the group (which has strict membership criteria) from the Numbers and Oddities site.
A typical numbers transmission consists of the following elements:
* A piece of music or other 'tuning signal' to enable the transmissions to be easily identified
* A set of numbers or letters to identify which agent the message is addressed to
* A message identifier (so that the agent knows whether this is a new message or one already received)
* The encryption key (page in the one time pad - see below)
* The message itself
It might end up looking something like this:
131 1 445 137
40169 89117 20298 35013 41171 11312 63536 93396 46878 16093
29358 33200 82800 62186 11396 84614 82364 31802 82184 13856
76542 20793 72496 02687 56367 66812 18736 23959 33356 29647
21272 04668 08563 59079 71771 45056 59223 74346 70438 99776
45393 22483 06897 74008 87564 11186 28378 86003 16942 77970
So how does the agent decode this message? It is suggested by those in the know, that they are unravelled using something called a 'one time pad'. The agent looks up the page in his book of one time pads which has a set of figures which allows the numbers to be translated into letters or words to decode the message. Once decoded, the page in the pad is burnt, eaten or otherwise destroyed. Without access to the pad, the message cannot be decrypted (eg by opposing security agencies) which makes it singularly secure. If the agent is captured and his pad falls into enemy hands, as long as the HQ is aware, they can stop sending messages to that agent. As each agent's pads are different, they cannot decode messages sent to other agents.
That such messaging systems are still used is, perhaps, not that surprising. That they should still rely on short-wave radio to send these messages to agents perhaps is. An e-mail could do the same job much more quickly and for less money. The advantage, however, of short-wave is that no specialist equipment is required to get hold of the message (short-wave radios are available in markets and bazaars around the world for a handful of dollars) and has the real advantage that the location and identity of the agent are not revealed by the transmission as they might be if an e-mail was traced by the authorities.
Hearing these transmissions is relatively easy. Mossad in particular seems to pepper the airwaves with transmissions, usually in the hours of darkness in Europe when local propagation is more straightforward (and presumably when agents are not out doing their day job!) Common frequencies include (though these change seasonally) 3840, 4270, 4880, 5435, 6840 and 9130 kHz from around 1800 GMT to at least 2000 GMT and later.
So, if you catch your Ukranian neighbour sunning herself in the garden whilst listening to seemingly random sets of numbers being read out on the radio, thanks to Wireless Waffle you now know exactly what is going on!
Saturday 13 June, 2009, 14:53 - Radio RandomnessOK, so Wireless Waffle was wrong about the real story behind the Brazilian use of the US FLTSATCOM military satellites (and their sister satellites, the UFO series). We thought it might all be innocent but it appears that there are groups of Brazilian truckers and similar using the satellites as their own personal CB radio. Calling the satellites 'Bolinho' (small ball), their activities have recently been brought to the fore by a raid by the Brazilian authorities on around 70 suspected 'hijackers'.
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The story has been reported on various web-sites and it seems that the equipment being used by the Brazilian pirates was relatively widely available and manufactured from standard PMR radios. The transmitters, it is claimed, were normal 144 - 174 MHz VHF devices with their transmitter outputs run through (varactor diode) frequency doublers to produce outputs in the range 288 - 348 MHz which ties in with the uplink frequencies of the satellites which are in the range 292 - 317 MHz. A simple downconverter can then be used to receive the signals.
The US spectrum regulatory authorities (the NTIA and FCC) clearly put pressure on the Brazilian spectrum authority (Anatel) to force them to act. Legally speaking, the Bolinho hijackers are guilty of operating a radio transmitter without a licence but whether or not they can be charged with any additional crime resulting from their use of the US satellites is unclear. It is unlikely that the use of the satllites represents any further crime in Brazil as the satellites are not Brazilian owned.
Various of the news stories which have covered the raids have suggested that the US satellites are now abandoned and are only in orbit in the case of emergencies and even go on to purport that the US may now decommission the satellites to put paid to any future Brazilian (or indeed other - it is known that there was some interference to the satellites from a radio station in the Philippines) piracy. This may be true but there are plenty of recent recordings of military traffic from these satellites. These might just be exercises but clearly the US military do still use the Bolinho Birds, despite claiming they are only used in emergencies. Then again, would you admit that your multi-million dollar military space hardware had been attacked by a group of mischievous miscreants using modest modified machinery?
P.S. The idea of a graphic depicting what is commonly known as 'a Brazilian' did cross our minds but that is, perhaps, cutting it too fine...!
Wednesday 6 May, 2009, 22:45 - BroadcastingThere is currently much ongoing debate, and some might suggest ensuing debacle, taking place to ensure that there is sufficient radio spectrum available for the London Olympic Games to be held in 2012. However, Wireless Waffle has uncovered the official Government plans for the use of the radio spectrum for the last Olympic Games held in London in 1948. Interestingly, these were before the main legislation relating to the use of the spectrum, the Wireless Telegraphy Act of 1949 were brought into power and thus predate any previous attempt to specifically control radio use in the UK.
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Let us step back to 1948... Much of London was still in ruins and rubble strewn streets were not uncommon. The budget for the games was £600,000, a figure which today would just about pay the salary of the organising committee for about a month. Food was still being rationed (indeed rationing did not end until 1954), King George VI was on the throne and Frankie Laine, Perry Como, Al Jolson and the Andrews Sisters topped the charts.
The Olympic games were televised using the EMI 405-line black and white system selected by the BBC before World War II as its preferred technology (having beaten the Baird 240 line system in trials). Only one transmitter in London was operative but an estimated 80,000 people had television receivers and were able to view the 64 hours of coverage that was broadcast. Radio coverage was also provided by the BBC and broadcast around the world using short wave.
So, with that in mind, here is the previously unpublished Government document which details usage of the spectrum. The original is not that easy to read (click on the image on the right to see it in full size) in pictorial format so here is the actual text.
Be it hereby enacted by the King's Most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the commandment of the same aforementioned, as follows:-What stands out from this is:
(1) No sporting personage, radio announcer or visual televiser shall establish or use any station for wireless replication of Olympic events or install or use any apparatus for wireless tomfoolery except under the authority of a licence in that behalf granted by the Postmaster General hereinunder purported to, and any person who establishes or uses any station for wirelessness of any nature or installs or uses any apparatus for wireless purposes except under and in accordance with such a licence shall be guilty of an offence of the most serious nature which shall be punishable by flogging, booting or in any such manner as is seen fit by His Most Excellent Majesty or his appointed Government torturer or executioner.
(2) A licence granted under this section (hereafter in this Decree referred to as an olympic wireless licence or 'owl') may be issued subject to such terms, provisions and commandments as the Postmaster General may think befitting, including in particular and in peculiar in the case of a licence to establish an olympic wireless station, limitations as to the positionality and nature of the station, the purposes for which, the circumstances in which, and the persons by whom the station may be used, and the manufactory of the apparatus which may be installed or used therein therefor, and, in the case of any other licence, limitations and hampering as to the apparatus which may be installed, operated or used, and the places or locations where, the purposes for which, the circumstances in which and the person or persons by whom the apparatus may be used for such purposes thereafter.
(3) Nothing or no item in this section shall authorise or approve the inclusion, in any olympic wireless licence relating solely to apparatus not designed or adapted for emission or transmission (as opposed to reception), of any term, item or provision requiring any person to concede any form of right of entry into any private dwellinghouse, manufactory, residence or abode.
(4) Through jurisdiction of this Decree, the commandment of the use of those radio wavelengths perporting to emissions authorised herinunderafter by an olympic wireless licence shall be designated for usage and utility as per the identification and categorisation indicated in the ensuing remainder of this document.
(5) Notwithstanding these categorisations and registrations of wireless lengths subscribed to by His Majesty's Government at the International Telecommunications Union 1947 Atlantic City Plenipotentiary Conference howsoever agreed, and in cognisance of the need to control and restrict miscreant emissions of wireless stations to other wireless stations, all emissive equipment of a nature requiring a licence under this Decree should be designed, manufactured, construed and operated in ways in which other wireless stations shall be safe from explosion and other maleficent discreation.
Wavelengths of below 1 metre (over 300 Mega Cycles per second) are reserved exclusively for secret Government use. The use of these wavelenghts shall remain secret and the fact that such wavelengths exist and the fact that the use of them is secret is also a secret and should be treated accordingly.
Wavelengths of between 3 metres and 1 metre (between 100 and 300 Mega Cycles per second) may be used for televisual distribution of motion or stationary pictorial information between private wireless stations which are fixed in location and fortitude.
Wavelengths of between 10 metres and 3 metres (between 30 and 100 Mega Cycles per second) may be used for televisual distribution of motion or stationary pictorial information between a public wireless station and domestic or official wireless receptors.
Wavelengths of between 100 metres and 10 metres (between 3 and 30 Mega Cycles per second) may be used for audible distribution of broadcast material to His Majesty's Overseas Territories and other fuzzy wuzzy lands to whom the English language is comprehensible. The use of some wavelengths within this range are reserved for secret Government use, the provisions of which are secret as described above therein.
Wavelengths larger than 100 metres (below 3 Mega Cycles) may be used for audible distribution of broadcast material to the United Kingdom of this marvellousness nation hereover. Some wavelengths within this range may also be used for the exchange of message between shipping and shipping or between shipping and port establishments for the perfunction of safety and maritime information exchange and for other safety matters as may be permitted in the olympic wireless licence therein permittivised. The use of some wavelengths within this range are reserved for secret Government use, the provisions of which are secret as described above therein.
* There is a clear division between different bands and their uses - this no doubt stems from the work ongoing at the ITU at the time in establishing the international frequency registration board.
* The highest frequencies were reserved for Government use. At the time, this was largely for radar and navigation tools that had proven invaluable in the success of the war effort.
* Some bands are shared between users (though the wording of the document would imply that within any given band, frequencies were only assigned to one use or another and that no true 'sharing' as we recognise it today was authorised).
* The operation of a wireless transmitting device permitted the authorities to access your property.
* There was nothing much on television tonight and so this drivel got written.
Note: one or more of the above may be substantially or materially inaccurate.
This document (erstwhile the 'Olympic Wireless Station Commandment of Licence Neccessity and Specifity Decree, 1948') clearly sets the framework for what became the WT Act of 1949 the following year and established the groundwork for spectrum regulation in the UK that still exists today and which will continue to apply until the London Olympics of 2012 and even after that. Perhaps.