Dr. David Kirkby wrote: Another RF engineer, who I don't know from working with antennas, said to me that antennas are a still a charlatan's paradise.
Those words rang true to me. I have yet to see a yagi type antenna that, in practice actually produced the gain it was specified to produce. True, I don't have a proper chamber in which to test antennas. I can only do real world comparisons. I have a pretty large collection of various 900 mHz antennas and on occasion, I set up my home made antenna test range and do measurements. This consists of a 900 MHz handie talkie with power turned down as low as it will go and PTT fastened down with a rubber band. Several hundred feet away, on a deck attached to my house at a height of about 10 feet, I have an HP 8924C to measure levels. First, I measure a home made groundplane for reference. Then the antennas to be tested are attached and measured. I realize that there are multiple places where error can and does creep in. But, I have found that when I actually try to use the antennas tested, the results are pretty accurate for real world conditions. I haven't found a good way just yet to test GPS antennas. There are just too many things besides gain to be considered. Many of which are beyond my capabilities. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
