There was a question recently about homebrewing an Elk type antenna. For those interested, the October 2001 QST had an article for homebrewing a 6 element 2 meter log periodic antenna by L. B. Cebik. If you are an ARRL member, you can get the article from their web site. Although not mentioned in the article, it should also work on 432 MHz on the third harmonic, but no performance figures are given. -- Euffey
I had a brief conversation with Kent, WA5VJB, at Dayton this year. Our discussion turned to log periodic antennas and operation at the 3rd harmonic. Kent said that the elements need to be "swept" forward in a herringbone pattern for proper operation on the 3rd harmonic.
For an example, look at a standard VHF television (log periodic) antenna. The elements of the antenna are quarter-wave for channels 2 through 6, and three-quarter wave on channels 7 through 13. Rather than being perpendicular to the boom, the elements are swept forward.
Steve, N9IP