Hi Andy,
Great choice to use elevated verticals! See Rudy Severn's info on why at:
https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf
If you are using the DX Engineering box shown at:
https://static.dxengineering.com/global/images/instructions/dxe-tfs4-80b-p.pdf
Why not add the ferrite material on the feedline to the rig, (as it
leaves the control box), and not the individual verticals?
Also if it were me, I'd bury the individual element feedlines as well as
the main feedline, to help reduce the RF pickup. I am guessing that
burying the coax won't mess with phasing, as long as you keep things
symmetrical. I am pretty sure it won't, as Rudy is using buried
feedline on his 160, 4 square.
Maybe someone can confirm or deny this on the list please?
73s and thanks,
Dave (NK7Z)
https://www.nk7z.net
Award Manager, 30MDG Grid Contest
ARRL Technical Specialist
ARRL Volunteer Examiner
ARRL OOC for Oregon
On 1/22/19 10:50 PM, Andy KU7T wrote:
Hi,
I am constructing an 80m 4 Square using DXE phasing unit. The instructions
clearly say to not add any matching components or decoupling devices like
baluns or coils between the phasing unit and the verticals.
I am using 4 elevated radials at about 9 feet height (I would rather not debate that
decision further…). It is usually suggested to use a common mode choke on any
antenna feed point, especially for elevated radials. Adding an conventional choke
would likely change my phasing.
So, I am looking for more information about making a current choke that does
not change the electrical length of the phasing coax cables. Is making a stack
of a few ferrite cores right on the feedline (maybe with a few coils if I have
the length available) ok to do?
I have read http://www.nu9n.com/images/RFI-Ham.pdf, and current chokes are extensively
discussed there. My question is whether winding on the phasing coax or sliding over
the coax will change phasing or not. I am thinking it does not, but wanted to check
here…
73
Andy
KU7T
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
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