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Bob, I've scratched most of my hair off my head already working with this antenna. If I make the radials about 25% shorter and the loop about 25% larger the antenna shows nearly identical gain. Change only one of these lengths and the gain goes down noticeably. I know that does not make much sense considering how the height of the cone might effect the radiator. It does not look like the larger loop beats the longer radials however the difference is only a few thousandths of a volt on the digital signal meter and within the range of normal signal fluctuations at 50 miles.

I'm also considering the fact that I am doing this testing in receive on the FM broadcast band. Most of the signals I can tune against are circularly polarized (or so they claim). I'm seeing strong signal increases when I tilt the entire antenna towards a 45 degree angle facing the transmitter. My next round of tests will be against a closer LPFM station that is vertical polarized only. This is to eliminate the chance my adjustments to the cone may be slightly increasing the response of the antenna in the horizontal plane.

CDX, I think it's safe to use the stock loop size. While I've changed this quite a bit I have not been able to add more gain doing so. I can get about the same gain back by adjusting the radials with a bigger loop but I can't find more. With respect to the new Vector, I'm not sure if they considered the specifications of the antenna I have them make for me. For many years I've been ordering mine with 1/4 wave radials.

I don't think Sirio cut corners on the new Vector because some of the new parts are clearly more expensive to manufacture. For example the new ribbed metal radial and connector hub has 3 times the weight of the cheap old one. The ball that I don't like on top probably costs more then a straight whip. I've also noticed with the longer radials it appears you can take some length out of the radiator without seeing a drop in gain. Although my tests doing this never indicated more far field gain.

I just placed a new order for stock from Sirio and directed several questions to their engineers concerning the new Vector. Particularly what factors influenced them to make these changes. For example was computer modeling used to improve the design. Hopefully they will have the time to respond to my questions. I know the factory is busy now with a flood of orders after their summer vacation.

<blockquote data-quote="Shockwave" data-source="post: 226960" data-attributes="member: 10882">Bob, I&#039;ve scratched most of my hair off my head already working with this antenna. If I make the radials about 25% shorter and the loop about 25% larger the antenna shows nearly identical gain. Change only one of these lengths and the gain goes down noticeably. I know that does not make much sense considering how the height of the cone might effect the radiator. It does not look like the larger loop beats the longer radials however the difference is only a few thousandths of a volt on the digital signal meter and within the range of normal signal fluctuations at 50 miles.I&#039;m also considering the fact that I am doing this testing in receive on the FM broadcast band. Most of the signals I can tune against are circularly polarized (or so they claim). I&#039;m seeing strong signal increases when I tilt the entire antenna towards a 45 degree angle facing the transmitter. My next round of tests will be against a closer LPFM station that is vertical polarized only. This is to eliminate the chance my adjustments to the cone may be slightly increasing the response of the antenna in the horizontal plane.CDX, I think it&#039;s safe to use the stock loop size. While I&#039;ve changed this quite a bit I have not been able to add more gain doing so. I can get about the same gain back by adjusting the radials with a bigger loop but I can&#039;t find more. With respect to the new Vector, I&#039;m not sure if they considered the specifications of the antenna I have them make for me. For many years I&#039;ve been ordering mine with 1/4 wave radials.I don&#039;t think Sirio cut corners on the new Vector because some of the new parts are clearly more expensive to manufacture. For example the new ribbed metal radial and connector hub has 3 times the weight of the cheap old one. The ball that I don&#039;t like on top probably costs more then a straight whip. I&#039;ve also noticed with the longer radials it appears you can take some length out of the radiator without seeing a drop in gain. Although my tests doing this never indicated more far field gain.I just placed a new order for stock from Sirio and directed several questions to their engineers concerning the new Vector. Particularly what factors influenced them to make these changes. For example was computer modeling used to improve the design. Hopefully they will have the time to respond to my questions. I know the factory is busy now with a flood of orders after their summer vacation.</blockquote>

[QUOTE="Shockwave, post: 226960, member: 10882"] Bob, I've scratched most of my hair off my head already working with this antenna. If I make the radials about 25% shorter and the loop about 25% larger the antenna shows nearly identical gain. Change only one of these lengths and the gain goes down noticeably. I know that does not make much sense considering how the height of the cone might effect the radiator. It does not look like the larger loop beats the longer radials however the difference is only a few thousandths of a volt on the digital signal meter and within the range of normal signal fluctuations at 50 miles. I'm also considering the fact that I am doing this testing in receive on the FM broadcast band. Most of the signals I can tune against are circularly polarized (or so they claim). I'm seeing strong signal increases when I tilt the entire antenna towards a 45 degree angle facing the transmitter. My next round of tests will be against a closer LPFM station that is vertical polarized only. This is to eliminate the chance my adjustments to the cone may be slightly increasing the response of the antenna in the horizontal plane. CDX, I think it's safe to use the stock loop size. While I've changed this quite a bit I have not been able to add more gain doing so. I can get about the same gain back by adjusting the radials with a bigger loop but I can't find more. With respect to the new Vector, I'm not sure if they considered the specifications of the antenna I have them make for me. For many years I've been ordering mine with 1/4 wave radials. I don't think Sirio cut corners on the new Vector because some of the new parts are clearly more expensive to manufacture. For example the new ribbed metal radial and connector hub has 3 times the weight of the cheap old one. The ball that I don't like on top probably costs more then a straight whip. I've also noticed with the longer radials it appears you can take some length out of the radiator without seeing a drop in gain. Although my tests doing this never indicated more far field gain. I just placed a new order for stock from Sirio and directed several questions to their engineers concerning the new Vector. Particularly what factors influenced them to make these changes. For example was computer modeling used to improve the design. Hopefully they will have the time to respond to my questions. I know the factory is busy now with a flood of orders after their summer vacation. [/QUOTE]

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