> What happens when such an antenna is mounted vertically?
You lose the "ground gain" ... it becomes a vertical dipole but
with nulls "broadside".
Most of the Cobweb style antennas I have seen stop at 20m yet they
would seem an ideal way to get reasonable size antennas on 30/40m, I
don't consider a full size 20m quad loop overly big. What's the
catch?
The difficulty of creating a sufficiently "strong" spreader assembly
to support the weight (particularly of the balun box) and the narrow
SWR. Assuming the same percentage bandwidth as on 20 meters, a 40 meter
element will have < 50 KHz of usable bandwidth without a tuner of some
kind. With high power and high SWR, I would be concerned for the balun
(matching transformer).
73,
... Joe, W4TV
On 10/30/2017 2:29 AM, Martin Sole wrote:
I think the Cobweb(b) antenna is an excellent antenna for limited space
with usefulness as a second antenna for those with a bit more space.
I've seen a lot of discussion about its use in the horizontal plane from
20m-6m. I have a couple of questions that might have simple answers.
What happens when such an antenna is mounted vertically?
Assuming vertical mounting is not massively detrimental, what happens
when a second passive element of similar shape is added at a distance,
ala 2 element yagi/quad?
Most of the Cobweb style antennas I have seen stop at 20m yet they would
seem an ideal way to get reasonable size antennas on 30/40m, I don't
consider a full size 20m quad loop overly big. What's the catch?
Martin, HS0ZED
On 29/10/2017 10:13, Dan Maguire wrote:
KK0SD wrote:
Has anyone actually modeled a Cob Web antenna?
More than you can shake a stick at. See
http://ac6la.com/aecollection9.html
Dan, AC6LA
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