Cortland Richmond wrote: > This is the kind of question that will get you in trouble, Kevin. The > message thread may never die! Like relativity, sometimes I think I understand baluns, and soon after that I know I don't... Magic!
> Do you have a particular application, or are you looking for information to > build your own antenna? I need to build an antenna for field strength measurements, for values probably of the order of 1-10mV/m. (This is not for compliance tests.) At present, I only need a fairly narrow band system, but future measurements would require something wider, say just over an octave from 900MHz up. I started looking at something like the Marchand balun, (see, eg. "Exact design of the Marchand Balun", Cloete, Microw. J., May, 1980), which I could re-use on other dipoles. The balun looks fairly expensive to manufacture, though. Its a difficult question, of what would be the correct way to make good field strength measurements. A resonant dipole will affect the fields I'm trying to measure, in any case. I am trying to follow the rules of minimising re-radiation from current on the feed cable due to imbalance, having the proper orientation of the feed while measuring, etc. Good polarization is not really an issue, as I am only after the maximum field values. Regards, Kevin -- ----------------------------------------------------------------------- Kevin Williams, MIEEE Electromagnetic Software and Systems (EMSS) [http://www.emss.co.za] Technopark, Stellenbosch, South Africa email: [email protected] tel/fax: +27 21 880-1880 +27 21 880-1727 ----------------------------------------------------------------------- --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], or [email protected] (the list administrators).
