If you homebrew your own antennas, and want to simulate the use of large diameter pipes, you can do so easily with flat conductive sheets of copper, aluminum, etc instead of heavy and costly real pipes.
The trick here is that a flat sheet conductor needs to be about 4 times the diameter of the pipe you want to simulate. So to simulate a 1-inch diameter pipe, you'd need about a 4-inch wide sheet. (RF seeks the edges of metallic structures - finding none on a cylindrical wire, it evenly coats the whole surface)
Be sure you can make a good mechanical / electrical connection to the sheet, and typically one can fold the edges at a 45-degree angle to bring one side of the sheet to a point for connection to the transmission line.
If you can find a very calm point in the attic, you could even use household aluminum foil provided you can get a good mechanical / electrical connection to it. (usually fold up the ends a lot at the feedpoint to get something you can actually connect into without tearing it apart.) I've made these, but am too ham-fisted not to break it while constructing it.
The trick here is that a flat sheet conductor needs to be about 4 times the diameter of the pipe you want to simulate. So to simulate a 1-inch diameter pipe, you'd need about a 4-inch wide sheet. (RF seeks the edges of metallic structures - finding none on a cylindrical wire, it evenly coats the whole surface)
Be sure you can make a good mechanical / electrical connection to the sheet, and typically one can fold the edges at a 45-degree angle to bring one side of the sheet to a point for connection to the transmission line.
If you can find a very calm point in the attic, you could even use household aluminum foil provided you can get a good mechanical / electrical connection to it. (usually fold up the ends a lot at the feedpoint to get something you can actually connect into without tearing it apart.) I've made these, but am too ham-fisted not to break it while constructing it.
