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.
Posted by Administrator
Posted by Administrator
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.