Rap 'n Tap
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From: Charlie Cotterman
Date: 11/12/00
Time: 10:24:22 PM
Remote Name: 131.238.48.96
Gerald - from what I've read in your post, the key phrase is 'serious'. You may not have room to go out - but have you tried up? A nice design in "Radios That Work For Free" is a helically wound vertical ("...All that is important is to get 425 feet of wire wrapped (no overlapping) on a length of support no less than 8 feet and put this up as high as possible..."). The formula given is 20ft of PVC 2" pipe and 850 turns at 1/4" spacing (425 ft total, resonant at mid-BCB). Something I'm going to be trying is three steel slinkies (you know, the spring toy) connected, and hung vertically. There's 180 feet of wire right there only 22' tall (this will take a bit of work to keep the spacing on the rope correct). If hung with the right spacing, the necessary number of slinkies for BCB resonance will be 100 ft long. (Because of their coiled configuration, the 66ft of wire per slinky in that 7 1/2 ft stretch effectively is only 33 ft.) But still, a vertical may be the way to go.
Something I used to have (and may resurrect) is a loop of wire that ran just around the roof edges and hid tucked under the shingles. The perimeter of my building totaled 135 feet -- and I actually used this antenna for a 100 watt transmitter. Worked great. Granted, it was only averaging 12 feet off the ground, but it worked. And in a loop configuration, that eliminates the need for a ground connection. That 135' is just barely resonant at the top edge of BCB, but hey, it's better than nothing. Like guru say, "RF gotta go somewhere..."
Charlie