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

Very good work Homer.

My best SWR bandwidth for my Sigma 4 was 2.3 mhz. I'm not sure what it was on Bob's super tuned Vectors, but he said he did see it improve as the antenna performed better.

I think you might expect to see a better bandwidth when recording the SWR bandwidth as apposed to when using an analyzer, so I chart both. I saw my BW improve just by using a coaxial choke directly at the feed point. It also produced a better curve what was very smooth and bowl shaped @ 100 khz step rate.

You mention that the radial support device is below the contact point of the gamma dog bone. I can't tell you if that makes a difference or not, but one might conclude that such an electrically neutral insulating device probably makes little or no difference. However, if you look at several of the manuals available on the INTERNET they all seem to find a reason to give a dimension for its placement along the radials. In fact on the LW150 antenna instruction sheet, which is almost void of dimensions, it shows this one dimension and maybe one other. I could never figure that out. So, maybe that placement might be something to consider fixing in your case.

I don't know if you took the chance to check between the changes you made, but it you did were you able to tell which change made the difference?

Have you been able to compare it to your 1/2 wave sleeved radiator?

Very good work Rube!

<blockquote data-quote="Marconi" data-source="post: 226512" data-attributes="member: 903">Very good work Homer. &nbsp;My best SWR bandwidth for my Sigma 4 was 2.3 mhz. I&#039;m not sure what it was on Bob&#039;s super tuned Vectors, but he said he did see it improve as the antenna performed better. &nbsp;I think you might expect to see a better bandwidth when recording the SWR bandwidth as apposed to when using an analyzer, so I chart both. I saw my BW improve just by using a coaxial choke directly at the feed point. It also produced a better curve what was very smooth and bowl shaped @ 100 khz step rate. &nbsp;You mention that the radial support device is below the contact point of the gamma dog bone. I can&#039;t tell you if that makes a difference or not, but one might conclude that such an electrically neutral insulating device probably makes little or no difference. However, if you look at several of the manuals available on the INTERNET they all seem to find a reason to give a dimension for its placement along the radials. In fact on the LW150 antenna instruction sheet, which is almost void of dimensions, it shows this one dimension and maybe one other. I could never figure that out. So, maybe that placement might be something to consider fixing in your case.&nbsp;I don&#039;t know if you took the chance to check between the changes you made, but it you did were you able to tell which change made the difference?&nbsp;Have you been able to compare it to your 1/2 wave sleeved radiator?&nbsp;Very good work Rube!</blockquote>

[QUOTE="Marconi, post: 226512, member: 903"] Very good work Homer. My best SWR bandwidth for my Sigma 4 was 2.3 mhz. I'm not sure what it was on Bob's super tuned Vectors, but he said he did see it improve as the antenna performed better. I think you might expect to see a better bandwidth when recording the SWR bandwidth as apposed to when using an analyzer, so I chart both. I saw my BW improve just by using a coaxial choke directly at the feed point. It also produced a better curve what was very smooth and bowl shaped @ 100 khz step rate. You mention that the radial support device is below the contact point of the gamma dog bone. I can't tell you if that makes a difference or not, but one might conclude that such an electrically neutral insulating device probably makes little or no difference. However, if you look at several of the manuals available on the INTERNET they all seem to find a reason to give a dimension for its placement along the radials. In fact on the LW150 antenna instruction sheet, which is almost void of dimensions, it shows this one dimension and maybe one other. I could never figure that out. So, maybe that placement might be something to consider fixing in your case. I don't know if you took the chance to check between the changes you made, but it you did were you able to tell which change made the difference? Have you been able to compare it to your 1/2 wave sleeved radiator? Very good work Rube! [/QUOTE]

Top Bottom