RadioBanter - View Single Post

[email protected] · October 27th 14, 06:59 PM posted to rec.radio.amateur.antenna

Lostgallifreyan wrote:
wrote in :

You do understand that a log periodic is a series of 1/2 wavelength dipoles
from the lowest to highest frequency of interest?

I do now. Point taken, this is not a portable thing... I looked very
briefly last night before sleep, my (wrong) assumption was that the elements
were basically directors using a log scale to compress the effective result
into a smaller space... I didn't realise that each was a separate normal
sized 1.2 wave dipole.

Well, almost...

The longest element is 1/2 wave at a frequency slightly below the lowest
frequency and the shortest element is 1/2 wave at a frequency slightly
above the highest frequency.

The taper in the element lengths is described by a log function.

The total number of elements and the boom length effect both the gain and
"flatness" of the SWR over the frequency range.

--
Jim Pennino