I want to replace the 450 ohm ladder line for my two DXE 720 ft long bi-directional beverages with two lengths of WD-1/TT field telephone wire. The wires will be secured only at the ends, but will be suported along their length by ceramic insulators mounted on 4x4 posts spaced every 60 ft. The spacing between the parallel wires will be about six inches. Here are my quesetions: First, does anybody know what the likely impedance is of this configuration, or if not, how to measure it? Second, if I keep the DxE matching trnsformers used with the 450 ohm ladder line, will beverage performance be degraded noticeably with the new wures if, say, the impedance of the new line turns out to be 600 ohms or so? In other words, as a practical matter how important to performance (e.g., F/B ratio and low-noise) is it to make sure impedances are matched.
Finally, a mechanical question. I want to have a pulley at one end of the parallel wires to equalize the tension in the wires. I've not been able to find a good pulley with a five or six inch diameter, except for nylon pulleys used for clotheslines. Do you think one of these could be used. There will be no motion of the pulley, since it is only used to equalize tension. The field telephone wire is rated at 200 lbs maximum tension, and I'm guessing the actual tension will be about half that. Thanks! Jim W8ZR _________________ Topband Reflector Archives - http://www.contesting.com/_topband
