Only a small portion of the LP elements carry significant current on
a given frequency - only a "few" elements are "active". This means
that the gain of an LP is generally equivalent to a non-optimum two
element or short boom three element antenna at best. Given the limited
number of active elements and the sub-optimal currents, side and back
rejection are generally significantly poorer than a well designed Yagi.
Log Periodic antennas provide coverage of a lot of "useless" spectrum
at the cost of efficiency, reduced performance in the narrow amateur
allocations and substantial mechanical complexity.
73,
... Joe, W4TV
On 10/25/2013 12:45 PM, Jim Brown wrote:
On 10/25/2013 9:38 AM, Gene Fuller wrote:
Would you like to add any comments regarding LP's.
I don't know enough about them to comment. I've only heard that their
gain is relatively low compared to a Yagi with the same boom length. It
has long been well known that the gain of a Yagi is related to boom length.
73, Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|