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Old November 21st 07, 09:09 PM posted to rec.radio.amateur.antenna
Robert Smts Robert Smts is offline
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First recorded activity by RadioBanter: Oct 2007
Posts: 13
Default Delta Loop Feed Orientation and Angle of Radiation

I'd like o be able to work some low-band DX.

I'm trying to figure out how to feed a proposed delta loop antenna.In the
documentation, such as in "Practical Wire Antennas" from the RSGB it is
suggested that there is a lot of difference in the main angle of radiation
from the antenna depending on where one puts the feedpoint.

I don't argue with that, but I'd like to know whether that is because the
effective mean height of the antenna varies according to the shape, or
because of where the antenna is fed.

Because I can support the antenna at about 100 feet, no matter how I orient
the antenna, the effective mean height will be more than a half wave above
ground, at least on forty and at twenty metres and higher, it will be more
than a wavelength.

Because it will be simpler to orient the antenna as an equilateral triangle
with the base along the top, and fed at the apex (pointing down) does the
feed location actually matter?

Diagram A - Easiest to feed.
--------------------------------------- 100 feet above ground
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| |


Diagram B Harder to Feed, and Feedline is 120 feet longer.


--------------------------------------- 100 feet above ground
\ -----
\ /
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\/


Comments on how well either of these is likely to work are welcome.

Bob, VE7HS