In a message dated 6/22/2008 9:21:37 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes:
A typical high-power FM transmitter will generally produce between 25-50Kw of RF output power, and through the magic of focused antennas we can boost this to an effective horizontal radiation of 100Kw maximum. That's 100Kw right at the "effective center of radiation". Now, ever heard of the inverse square law? Basically, each time you double your distance away from a point-source, the energy which previously was falling upon a surface with the size X is now spread out over a surface with the size X2. So, build an imaginary sphere with a radius of 1m around a point-source antenna spitting out 100Kw. The sphere has a surface area of 12.56m2, so each square meter is receiving 7.96Kw of power. Now, move 1 meter further away, and the power drops to 1.99 Kw. Move another meter away, and the power drops to 884 watts. Move 1 more meter away, and the power is down to 497 watts. And bear in mind, we're only 13 feet down an 800 foot tower. Now, I'd consider a 150cc scooter to be just about the minimally practical motorized vehicle for in-town commuting. Depending upon exactly which manufacturer's spec you believe, such engines generally produce somewhere in the vicinity of eight HP. That's 6Kw. So, assuming you are always operating in an area where you are continuously exposed to the maximum permissible RF radiation at all times (ie: your commute to work takes you past a hundred full-power FM and VHF transmitters) you could power your scooter by mounting an antenna on the back with an area of three square kilometers. Who volunteers to go first? You're assuming that the radio waves must be broadcast, that the frequencies must be what they are today, and that the waves would be the primary source of "power" or "fuel" for the vehicle. As mentioned several times, if the waves were used to power/generate light, the light could power photovoltaic cells to produce electricity. As a Radio Engineer, you're aware of the progression in electronics capbilities today from that of only 40 years ago. What may not seem possible today is only development-time away. Jerry aka LGO **************Gas prices getting you down? Search AOL Autos for fuel-efficient used cars. (http://autos.aol.com/used?ncid=aolaut00050000000007)
_______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
