[TowerTalk] 40 meter delta

Marinus Loewensteijn zl2ml at hotmail.com
Wed Nov 12 02:26:07 EST 2008


Situation is: small lot, not enough room to put up full size 40 mater dipole, shortened just OK. Some trees (neighbours, cannot do much about them) Property is sloping (long path to open sea), two story "town house (two houses under one roof).
 
Presently experimenting with a 40 meter rotatable dipole and not happy. A lot of local interference and not enough DX.
 
Did a lot of exploring on the internet but cannot seem to come up with something that is going to look like a "garanteed winner". 
 
Have thought about half wave L antenna, centre fed at the top. Cannot make the top leg much longer than approx 11.5 meters but to the ground more is possible. However am concerned about the noise level.
 
Am now considering: A "sloping delta loop, the top leg horizontal, one leg diagonal and one leg "vertical" (90 degree angle with the top horizontal leg - but still sloping ). Will be feeding it in the top corner where the 90 degree corner is. Slope will be towards sea and bottom is expected to be around 7 foot from the ground.
Main reason to consider a loop is that a loop is considered to be performing reasonably well in close proximity to surrounding trees and is supposed to give a few S points less noise.
 
MMANA gives a favourable pattern but I know MMANA is not too accurate when modelling close to the ground.
 
The more knowledgable antenna experts under the group (at least more than me): what do you reckon: a good idea or should I go for something else?
 
Thanks in advance
marinus, ZL2ML
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