>> If I assume that the top loaded antenna acts as a quarter wave stub, that is it is extremely efficient at radiating all the power presented at the base and not reflecting any back, and if I further assume this is CB band or higher (essentially at or above 30 MHz), then 600 Watts 5 meters away (one car length behind) yields 47 V/m (70 mA drive). <<
Actually, I stopped an engine at about 3.5 Mhz, with only 100 watts. A good mobile antenna at 80 meters will see some few ohms of loading resistance, perhaps 10 ohms of ground loss, and have a radiation resistance on the order of one ohm. But assume the higher power as representative of a typical mobile amplifier. The fields near the auto are high and ground loss will not be as large a component in the near field for another auto that is close enough. One of the famous stunts is to walk around the car with a fluorescent lighting tube in one's hand, illuminating the area without any direct connection. Cheers, Cortland (The firm for which I work does not Know what I choose to write, Therefore be warned, they do not say What chances to your sight.) ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
