Experimental Vertical Repaired and Tuned • Experimentation Begins Tonight
This morning I corrected the problem and retuned the test vertical in the marsh, as seen below.
"Radial-less" Saltwater Marsh Vertical SWR Sweep
52 Ohm feedpoint impedance at resonance,16 Ohms ground loss.
50% efficient without radials. SWR under 1.2 across band.
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Remember, a 50 Ohm feedpoint impedance on a 1/4 WL vertical means about 14 Ohms of ground loss since the optimum feedpoint impedance for such an aerial is 36 Ohms. So what we learned thus far is that four (4) short ground rods (2.5 feet long) spaced 4' apart around the vertical produced 16 Ohms of ground loss at resonance. Another finding is that it is possible to resonate the vertical against the ground rods, e.g. the reactive component is manageable at resonance. The only other thing to find out is whether or not the aerial will survive high winds. So we are looking forward to A/B comparisons between the two verticals on-the-air..
Once again, here she is. Standing tall and proud. The center of her is double-walled aluminum stiffening her in the winds.
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