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On Tue, 26 Aug 2003 09:28:53 -0600, "Ken Bessler"
wrote: 2.330 mhz, 1:1 8.040 mhz, 1.8:1 13.630 mhz, 1:1 new! 23.615 mhz, 1.2:1 I didn't add any coax to make the turns - I simply used the slack in the line I had to wind the turns. I can't wind any more without adding coax at this point..... I have 8-1/2' of rg8x between the coil and my Z11 autotuner. Anyone know what's going on here? FYI the antenna is a 153'2" dipole wrapped closely around a brick building. The feedpoint is on the third floor window, the ends are 1) chest height and 2) 10' high. Everything is very well grounded (covered here before)...... Hi Ken, One of several things going on, barring more data. I have 8-1/2' of rg8x between the coil and my Z11 autotuner. How much distance between the choke and the feedpoint? How much distance between the auto tuner and your station? If considerably less then that means you and your domicile are immersed in the very near fields of the antenna. This complicates matters and certainly offers the prospects of Common Mode issues galore (simply through imbalances offered by life in the 'burbs). How near is too near? For 160M you cannot escape being part of the radiator by living in the conventional house in a conventional tract. Higher frequencies only reduce this prospect by degrees. For 20M the near field, by various assessments, extends as little as 20M away from the antenna to more conservative expectations of 100M to 200M. How much does it matter? You seemed to have reduced what Common Mode issues you could perceive enough. This doesn't mean you completely removed them, just reduced them below your thresh hold of detection. So, in that sense, mattering is an issue of detection and if your neighbors do not detect your activity, nor do you burn yourself on equipment ground, then there is no "problem." If you want to increase your thresh hold of detection, break a ferrite bead in half (to get a C shaped, half torus) and wrap the leads of a high output LED around it once (same thing as shorting the leads and inserting the half torus through them). Red LEDs rated at 1 Candela or better are very suitable and can be found at Radio Shack. Hold the half torus near conductors and check for a glow. This should offer 10 to 100µA sensitivity and something new to worry about. ;-) 73's Richard Clark, KB7QHC |