Una pregunta..... en 140 khz +- 500 hz escuchas algo? porfa si escuchas una señal tipo RTTY podrias mandar el audio para comparar si es lo que escucho algunas veces??? tks Claudio
--- El jue 18-jun-09, juan jose <[email protected]> escribió: De: juan jose <[email protected]> Asunto: Re: [ondalarga] sabeis que es esto? A: [email protected] Fecha: jueves, 18 junio, 2009, 6:58 pm ok, muchisimas gracias. no sabia que hubiera un sistema como este en onda larga. gracias por vuestra ayuda, e encontrado la web http://www.datatrak .ws/services_ datanetworks. asp que habla del tema nuevamente gracias 2009/6/18 Claudio Periolo <radioclaudio@ yahoo.com> Es Datarack. Datatrak is a medium-area LF automatic vehicle location (AVL) system operating in the UK, Benelux countries, Germany and Austria. It is operated by Securicor Information Systems in the UK and by Siemens-Datatrak in mainland Europe. It was originally developed to fulfil a need for the monitoring of Securicor's own parcel and security vehicles, however it is now marketed to a number of other customers. The system is a conventional hyperbolic positioning system where a number of stations making up a chain transmit in sequence on a common pair of frequencies in the band 130 to 170 kHz. The receiver calculates it's position and communicates this back to the control centre (Swindon in the UK) by means of a UHF radio system that provides similar coverage to the LF network. The system is enhanced by the provision of Event Activated Tracking (EAT) or 'Trak Bak' as Securicor call the product. This allows a stolen vehicle to be tracked and aprehended. Also, the UHF component may monitor various inputs from the vehicle, providing a telemetry function. There are apparently 14 sites in the UK but their location is unknown. The sequential transmissions are clearly audible at around 145 kHz in the UK, the interesting thing about them is that they 'warble' as if FSK modulated at around 20bps. Using Manchester coding, the transmission would still be usable for positioning as long as the phase were averaged over many symbols. Buscando en listas los vas a encontrar de donde son, si los encuentro lo envio. 73's Claudio --- El jue 18-jun-09, juan jose <eb3...@gmail. com> escribió: De: juan jose <eb3...@gmail. com> Asunto: [ondalarga] sabeis que es esto? [2 Attachments] A: ondala...@yahoogrou ps.com Fecha: jueves, 18 junio, 2009, 7:23 am hola, escuchando por la onda larga me e encontrado con esto, sabeis que es? es en 133,78 y 147,04 khz saludos ¡Obtén la mejor experiencia en la web! Descarga gratis el nuevo Internet Explorer 8 http://downloads. yahoo.com/ ieak8/?l= e1 ____________________________________________________________________________________ ¡Obtén la mejor experiencia en la web! Descarga gratis el nuevo Internet Explorer 8. http://downloads.yahoo.com/ieak8/?l=e1
