[GroundUrMast]

There is an existing thread that started with historical rhombic information.

This thread is intended for modeled and built examples.

The following material may be of interest however. (From the earlier rhombic thread):

Here is some additional information, including a link to "Edmund Laport's textbook Radio Antenna Engineering, published in 1952 and now out of copyright and freely available, scanned and processed into PDF by Dave Platt, AE6EO." (This is a 25 MB file)

http://www.cromwell-intl.com/radio/r...-antennas.html

Rhombic antennas are dealt with beginning on page 315.

And another collection of information re. the Rhombic: http://www.dxzone.com/catalog/Antennas/Rhombic/