Tom,
What is a lot taller?
Would an aluminum or steel (or combination) mast extension with pointed
tip, extending say 10-20 feet above the top beam -- let's say one for
20m -- help to reduce corona discharge noise in the top beam?
73/Jon AA1K
On 11/16/2012 6:58 PM, Tom W8JI wrote:
Hi would
What is a lot taller?
I can't answer that question specifically. It varies with e-field conditions
and the type of antennas and structures.
The corona is a micro power noise generator so it radiates noise, and the
target has to neutralize the field near other points so they don't break
I used to have up all Telrex monobanders ( and by the way they are still
great antennas despite what some think). The 8 el 15 and the 5 el 20 all
had corona balls at the end of the elements. These were designed years
ago (company defunct about 1995)...
73,
John, W4NU
The T Match tuner is what sits in the house Price. The T Match feed on the
antenna is completely different, is grounded to the boom on the all metal
design
and is no more prone to P-static than any other feed system.
My own yagis use a T Match from 28 to 432 MHz and work very well and without
I've got an FT-240-43 core on which I'd like to wind RG58 to make a choke
for the feedpoint of my inverted-L.
I've seen articles that studied the optimum number of turns for air-core
chokes, but don't recall seeing any for toroidal chokes. Can anyone offer a
pointer (or empirical data) that
Joe...I was wrong in my post. My verticals are 1/2 wave apart on 80m, which is
the same as 1/4 wave on 160.
After writing my message, I went back and added the 66' for clarity, and should
have been 132'
You are correct, using RG8X with velocity factor of .78, the phasing lines are
about
Joe...I was wrong in my post. My verticals are 1/2 wave apart on 80m,
That changes things ...
So the question remains, how to properly feed phased verticals that
are physically 1/2 wave apart
Seems to me you have two options ... feed them in phase which provides
a bidirectional pattern
This looks like the Engineering Phasing report mentioned. I have an older
version, this one seems to be reformatted. Give it a try.
http://www.classicinternational.eu/_clientfiles/info_extra/hygainphasedverticals.pdf'
