What affect is there of vertical *resistance* variations are the common 4-square boxes?
N6LF’s QEX article shows quantitatively the performance hit associated with using non-resonant elevated radials. Which is interesting because non-resonant radial lengths reduce the sensitivity of individual elevated radial variations from ideal. However, by altering the relative lengths of the vertical/radial, the feedpoint R moves around. I ran a simple test case pair in EZNEC. First was the resonant radial case (length is the same as the vertical radiator). Second was shortened radials (about 10%) with the vertical lengthened to restore the same X=0 frequency. The feedpoint R moves from 32 ohms in the symmetric case to about 40 ohms in the short-radials case. The R has got to translate into a drive impedance shift - but I am wondering what the expected impact to the array should be? 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie _________________ Topband Reflector
