On 1/8/2015 5:36 AM, JC wrote:
"An array of loops is two loops for two directions.
Hi guys
The simple solution that is working very well since 2009 is the HWF. Why not
two horizontal loaded loops end-fire. Two identical horizontal loops see
the ground wave signal at the same way Va=Vb and because the 180 degree
I have been modeling horizontal loops recently. The idea is to
reject vertically polarized ground wave noise. As far as I can tell, a
horizontal loop rejects vertically polarized noise from any direction.
As opposed to a dipole that receives vertically polarized signals
from the ends. You can make the loop just about any size or shape
and terminate the side opposite the feed with a resistor of around 1000
ohms to get a cardioid pattern. There is a resonance when the perimeter
of the loop is a half wave long, so you need to stay somewhat below this
length, which would be something like 260 feet on 160 meters.
That's a huge loop. The higher the loop and the bigger the loop, the
more signal you get (that is gross signal, not SNR). You need to
overcome your preamp noise.
As JC says, these loops can be the building blocks of an array.
I am going to try to get a horizontal loop aimed at 70 degrees
up for the upcoming CQWW contests as a proof of concept. In
the recent SP, I tried a horizontal dipole, but it was no better
than the transmit vertical. In the past, dipoles have been good
receiving antennas. I am thinking it is a matter of what direction
the dominant noise is coming from as to whether they work. The
loop doesn't have that issue.
Rick N6RK
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|