[TowerTalk] Optibeam Log Yagi

[vk3od at yahoo.com]

W4RNL had extensive large LPDA models. Many of the Optibeam log periodics look identical to the W4RNL models in terms of number of elements, boom length and the use of the of director element. His models and data are very credible in terms of the gain performance.

https://antenna2.github.io/cebik/content/lpda/9556.html
https://antenna2.github.io/cebik/content/lpda/3lpda.html

Cebik also compares these optimised log periodic antennas to a forward staggered yagi that covers all ham bands including the WARC bands. I believe it was a ON7ANT design.

There also was a "optimised log periodic" design in a QST magazine. This antenna was highly optimised for the ham bands and delivered from memory the equivalent performance of a 3 element 7 Dbi yagi. The NEC model was available.

WA3FET apparently has done some design work on some leading edge optimised log periodic designs that was mentioned in a Dayton forum in one of his presentation. The presentation can be found on K3LR's web page.

It makes you pause and think when something like a 4 Element Steppir that covers all bands can deliver the same performance as a monster LPDA on 60 ft boom with 22 elements! A shame Steppir is no longer in the ham business.

73
Craig
VK3OD