Wireless Waffle - A whole spectrum of radio related rubbish
Super Signal Holiday HF Antenna Apparelsignal strength
Friday 7 August, 2009, 09:31 - Radio Randomness
Posted by Administrator
August 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.

harrier hf antennaBeing 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

ideal antenna mountIn 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.

bikini hf antennaAfter 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.
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Come Spy With Mesignal strength
Thursday 23 July, 2009, 08:00 - Radio Randomness
Posted by Administrator
It 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.

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
000 000


one time padSo 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.

ukranian spy neighbourHearing 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!
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SatJacking, Brazilian stylesignal strength
Saturday 13 June, 2009, 14:53 - Radio Randomness
Posted by Administrator
ufo fltsatcomOK, 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'.

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.

brazilian birdsThe 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...!
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Don't Wave Goodbye to Short-Wavesignal strength
Tuesday 28 April, 2009, 07:22 - Radio Randomness
Posted by Administrator
wave goodbye to shortwaveThe threat to short-wave reception caused by PLT (a.k.a. BPL) devices is something that has been covered on Wireless Waffle on numerous previous occasions.

Whilst it hasn't reached the point of naked protestors parading along the streets of London just yet, a while ago the technical group trying to curb the spread of these devices petitioned the UK Government to do something about it. The Government's response was rather lacklustre:
As with all electrical and electronic products sold in the UK, Power Line Technology (PLT) equipment is required to meet the relevant regulations before it can be placed on the market. In particular, it must comply with the Electromagnetic Compatibility Regulations 2006 (the EMC Regulations) ... and any person who places such products on the market ... must ensure that the products comply and apply the ‘CE’ mark.

The Department for Business Enterprise and Regulatory Reform (BERR) is responsible for the EMC Regulations. Enforcement powers are delegated to local Trading Standards offices, and to Ofcom where there is a radio spectrum protection or management issue. Ofcom estimates there are around 500,000 pieces of PLT equipment in use in the UK. Ofcom have received around 84 individual complaints of interference attributed to PLT equipment. All of these complaints are in the process of being investigated or have been successfully resolved. Each complaint is investigated on its own merits. We do not believe an outright ban of all powerline adaptors is justified.

A lot of buck-passing with the end result that nothing happened. But not to let a roaring lion lie, the good people at UKQRM have submitted a second petition:
We the undersigned petition the Prime Minister to require the relevant regulatory authority namely Ofcom to take active and speedy measures to test samples of all makes and types of PLT device and to remove from the UK market all those devices where the sample is found to be non compliant with the requirements of the Electromagnetic Compatibility Regulations 2006. And to take all practicable and necessary steps to prevent anyone placing non compliant PLT devices on the UK market now and in the future.

Wireless Waffle believes that the spread of PLT devices is something which needs to be checked and that the more cage rattling that is done, the better the chances of some real action being taken.

If you are a UK radio user, listener or someone who depends upon the radio spectrum for your profession or livelihood in the UK, whether you are interested in short-wave or not, we would urge you to sign the petition. The slow march of PLT devices represents what will no doubt be the first of many attacks on the precious raw material which underpins so many UK jobs and with the credit crunch already hitting people's employment, anything which protects future generations has to be good.

Please go and sign the petition at http://petitions.number10.gov.uk/SaveShortwave2/ and add your name and voice to ensure that future voices will be able to hear each other!

Let nation (be able to continue to) speak peace unto nation... as someone once said.
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