Here are some dimensions for the construction of Rhombic antennas taken from the War Department Technical Manual TM 11-2617 “Antenna Kit for Rhombic Transmitting Antenna” .
This manual is available on CD on eBay.
A larger image may be downloaded from here .
I do have design data for Rhombics up to 1000′ leg lengths but that data does not include pole spacings.
100 foot poles should be set 12 feet in the ground. My end poles are 80 footers and are set down 8 feet with an additional 10 feet of dirt piled up around the bases. They are then guyed with steel guy wires every 120 degrees on two levels – middle of pole and at the top.
I use #8 Hard Drawn copper for my USA Rhombic, and #10 CopperWeld for my smaller Rhombics. I have also purchased 2,200lbs of #9 AlumoWeld antenna wire for my future projects. The AlumoWeld wire has a breaking strength of 2000lbs.
Edmund LaPort’s “Radio Antenna Engineering” is a fantastic resource when constructing wire antennas. The book can be downloaded in electronic form from LULU.COM and also from this alternative site . It can also be downloaded from my site. Please right click on this link to download the book (38MB) – courtesy of Dave Platt, AE6EO
A.E. Harper’s Rhombic Antenna Design is available from AstroLogos Books
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