Use a sharpie to mark where the the dog bone is on both the vertical and gamma rod currently then move it in and/or out until the SWR goes down.
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
New Sirio Vector 4000 on the Tower.
- Thread starter Drifter
- Start date
Alexis
when grounding & un-grounding the antenna changes vswr it indicates you have common mode current flowing on that wire & radiating, either when its connected or when its disconnected,
my money would be on you have increased cmc on the wire when you connect it because 20ft is closer to an electrical 1/2wave than it is odd 1/4wave multiples (3/4wave)
if it was closer to 3/4wave i would have said the opposite, disconnecting it from the ground rod would cause an increase in cmc,
electrical 1/2waves of any conductor such as the mast, outside surface of coax braid & ground wires that are connected to ground at one end & the antenna radial coax junction at the upper end, have a low common mode impedance,
that promotes high current & unwanted radiation,
most of the difference people see in signal when comparing vertical antennas at the same tip height is due to this unwanted radiation not the antenna istself.
when you can't adjust vswr very low by pulling the gamma rod & radiator length you have to adjust the gamma strap/dogbone up or down a little & readjust the other two again.
good luck,
when grounding & un-grounding the antenna changes vswr it indicates you have common mode current flowing on that wire & radiating, either when its connected or when its disconnected,
my money would be on you have increased cmc on the wire when you connect it because 20ft is closer to an electrical 1/2wave than it is odd 1/4wave multiples (3/4wave)
if it was closer to 3/4wave i would have said the opposite, disconnecting it from the ground rod would cause an increase in cmc,
electrical 1/2waves of any conductor such as the mast, outside surface of coax braid & ground wires that are connected to ground at one end & the antenna radial coax junction at the upper end, have a low common mode impedance,
that promotes high current & unwanted radiation,
most of the difference people see in signal when comparing vertical antennas at the same tip height is due to this unwanted radiation not the antenna istself.
when you can't adjust vswr very low by pulling the gamma rod & radiator length you have to adjust the gamma strap/dogbone up or down a little & readjust the other two again.
good luck,
Shadetree Mechanic
Delaware Base Station 808
I had to wind a coax choke at the feed point. I was turning the light in the china cabinet on and off. haha
I didn't use a tower for my Vector 4000. I used a poor man's tower a big Georgia pine.
It's 110ft to the tip top, and it has a 10k gamma.
[photo=medium]6594[/photo]
[photo=medium]6595[/photo]
Now if mother nature leaves it alone. lol
It's 110ft to the tip top, and it has a 10k gamma.
[photo=medium]6594[/photo]
[photo=medium]6595[/photo]
Now if mother nature leaves it alone. lol
I miss being able to put my antenna up in a tree. 25 years ago I lived on a hill and had huge cedar and evergreen trees all around and I pushed a A99 on a pole out the top of a 80' tree and I could cover crazy distance in all directions with 4 watts. People thought I had a huge amplifier 
10 years ago I lived on another hill with big trees and put a dipole up 60 feet up between two trees and again just put out a great signal.
Now, no more hill and no trees. Have to rely on watts.
10 years ago I lived on another hill with big trees and put a dipole up 60 feet up between two trees and again just put out a great signal.
Now, no more hill and no trees. Have to rely on watts.
Yes it will. Hopefully it's flexible enough to sway and not snap! Fingers crossed. The silver lining is that the antenna was given to me so I'm only out the tree climbing cost.
Its been over two months in the top of the pine with no issues! Had several intense t-storms with straight line winds and all is good.
Now the bad news (sort of) is I'm moving to Huntsville in a month and will have to get my tree guy to come back and take down the vector. Not way I'm leaving it behind.
Now the bad news (sort of) is I'm moving to Huntsville in a month and will have to get my tree guy to come back and take down the vector. Not way I'm leaving it behind.
The vector is up 20ft on a pushup pole. Finally got moved and settled in Huntsville. Now time to plan for a tower!