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.
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

Message

I agree that I need a good base point to start with, that is why I am starting with different and better coax. I would disregard the first set of test numbers as the coax was not 1/2 wave length. Now that I have a base point I will do the mod without changing anything other than the top radial. I am not so concerned about being in the center of the band so much as to see of the straight radial is more broad banded. I can always go back and retune as it only takes about 5min. to lower the antenna down and make a change.
Sorry for the miss information earlier but I am learning as I go. I cut the new jumper to 18'-15/16" acording to the antenna book this should be 1/2 wave but now I am hering that it should be 15' 4-1/2" ???

Bob85 suggest that the coax be dead center down the mast. That it is. I was considering running it down the inside of the mast also. unlike the original my mast pole is axactly centered between the mast pole the original design has the mast pole slightly ofset. I achieve this alignment by putting a bends in the top bracket as you can see in the photos. The angle of the bends and all of the dimensions are such that the original dimensions between the mast and lower legas as well as between the two lower legs are the same.I am taking the measurements on my roof with a mast pole about 19" long stuck into a 3" tripod. The 1/2 wave jumper is just about at the level of the top of the tripod and that is where I hook the analyzer. There is about 9" from the top of the tripod to the bottom of the loop. This keeps my body away from the antenna and directly below it.

<blockquote data-quote="Starduster" data-source="post: 208350" data-attributes="member: 6264">I agree that I need a good base point to start with, that is why I am starting with different and better coax. I would disregard the first set of test numbers as the coax was not 1/2 wave length. Now that I have a base point I will do the mod without changing anything other than the top radial. I am not so concerned about being in the center of the band so much as to see of the straight radial is more broad banded. I can always go back and retune as it only takes about 5min. to lower the antenna down and make a change.Sorry for the miss information earlier but I am learning as I go. I cut the new jumper to 18&#039;-15/16&quot; acording to the antenna book this should be 1/2 wave but now I am hering that it should be 15&#039; 4-1/2&quot; ???&nbsp;Bob85 suggest that the coax be dead center down the mast. That it is. I was considering running it down the inside of the mast also. unlike the original my mast pole is axactly centered between the mast pole the original design has the mast pole slightly ofset. I achieve this alignment by putting a bends in the top bracket as you can see in the photos. The angle of the bends and all of the dimensions are such that the original dimensions between the mast and lower legas as well as between the two lower legs are the same.I am taking the measurements on my roof with a mast pole about 19&quot; long stuck into a 3&quot; tripod. The 1/2 wave jumper is just about at the level of the top of the tripod and that is where I hook the analyzer. There is about 9&quot; from the top of the tripod to the bottom of the loop. This keeps my body away from the antenna and directly below it.</blockquote>

[QUOTE="Starduster, post: 208350, member: 6264"] I agree that I need a good base point to start with, that is why I am starting with different and better coax. I would disregard the first set of test numbers as the coax was not 1/2 wave length. Now that I have a base point I will do the mod without changing anything other than the top radial. I am not so concerned about being in the center of the band so much as to see of the straight radial is more broad banded. I can always go back and retune as it only takes about 5min. to lower the antenna down and make a change. Sorry for the miss information earlier but I am learning as I go. I cut the new jumper to 18'-15/16" acording to the antenna book this should be 1/2 wave but now I am hering that it should be 15' 4-1/2" ??? Bob85 suggest that the coax be dead center down the mast. That it is. I was considering running it down the inside of the mast also. unlike the original my mast pole is axactly centered between the mast pole the original design has the mast pole slightly ofset. I achieve this alignment by putting a bends in the top bracket as you can see in the photos. The angle of the bends and all of the dimensions are such that the original dimensions between the mast and lower legas as well as between the two lower legs are the same.I am taking the measurements on my roof with a mast pole about 19" long stuck into a 3" tripod. The 1/2 wave jumper is just about at the level of the top of the tripod and that is where I hook the analyzer. There is about 9" from the top of the tripod to the bottom of the loop. This keeps my body away from the antenna and directly below it. [/QUOTE]

Top Bottom