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Hello Starduster, for some time I have touted the Starduster and the AstroPlane. I have claimed that if you get the tips of these two up as high as any other of the longer antennas you will see similar or better local signals when compared side by side. Last summer I compared RX signals and made bandwidth plots while tuning of several vertical CB antennas that I have. I posted all of my results in my profile albums. See: http://www.worldwidedx.com/members/marconi.html

I think you suggest modifying your Top One to look like the driven element on the AstroBeam. I suppose that means to make the top element a straight full 1/4 wave element, right? Here is one I modified last summer when I was comparing it to my Sigma IV.

[ATTACH]2603[/ATTACH]

IMO, seeing a drop in frequency when you raise an antenna may well happen in some cases, but I see the same thing, for sure, when changing the length of the feed line. IMO, this shifts the apparent resonance and does so when my tune is not perfectly resonant at the same tuned frequency of choice. I think this has to do with the antenna being reactive, showing a standing wave on the feed line. Example: in your comments, if you tuned your AP with a jumper and then when you raised the antenna you used a longer feed line, then you might see such a response---and this is due to feed line transformation IMO. If this is not the case in your situation, then raising probably caused the drop in frequency.

Good luck and keep us posted on your results.

<blockquote data-quote="Marconi" data-source="post: 206726" data-attributes="member: 903">Hello Starduster, for some time I have touted the Starduster and the AstroPlane. I have claimed that if you get the tips of these two up as high as any other of the longer antennas you will see similar or better local signals when compared side by side. Last summer I compared RX signals and made bandwidth plots while tuning of several vertical CB antennas that I have. I posted all of my results in my profile albums. See: <a href="http://www.worldwidedx.com/members/marconi.html" target="_blank">http://www.worldwidedx.com/members/marconi.html</a>&nbsp;I think you suggest modifying your Top One to look like the driven element on the AstroBeam. I suppose that means to make the top element a straight full 1/4 wave element, right? Here is one I modified last summer when I was comparing it to my Sigma IV.&nbsp;[ATTACH]2603[/ATTACH]&nbsp;IMO, seeing a drop in frequency when you raise an antenna may well happen in some cases, but I see the same thing, for sure, when changing the length of the feed line. IMO, this shifts the apparent resonance and does so when my tune is not perfectly resonant at the same tuned frequency of choice. I think this has to do with the antenna being reactive, showing a standing wave on the feed line. Example: in your comments, if you tuned your AP with a jumper and then when you raised the antenna you used a longer feed line, then you might see such a response---and this is due to feed line transformation IMO. If this is not the case in your situation, then raising probably caused the drop in frequency.&nbsp;Good luck and keep us posted on your results.</blockquote>

[QUOTE="Marconi, post: 206726, member: 903"] Hello Starduster, for some time I have touted the Starduster and the AstroPlane. I have claimed that if you get the tips of these two up as high as any other of the longer antennas you will see similar or better local signals when compared side by side. Last summer I compared RX signals and made bandwidth plots while tuning of several vertical CB antennas that I have. I posted all of my results in my profile albums. See: [URL]http://www.worldwidedx.com/members/marconi.html[/URL] I think you suggest modifying your Top One to look like the driven element on the AstroBeam. I suppose that means to make the top element a straight full 1/4 wave element, right? Here is one I modified last summer when I was comparing it to my Sigma IV. [ATTACH]2603.vB[/ATTACH] IMO, seeing a drop in frequency when you raise an antenna may well happen in some cases, but I see the same thing, for sure, when changing the length of the feed line. IMO, this shifts the apparent resonance and does so when my tune is not perfectly resonant at the same tuned frequency of choice. I think this has to do with the antenna being reactive, showing a standing wave on the feed line. Example: in your comments, if you tuned your AP with a jumper and then when you raised the antenna you used a longer feed line, then you might see such a response---and this is due to feed line transformation IMO. If this is not the case in your situation, then raising probably caused the drop in frequency. Good luck and keep us posted on your results. [/QUOTE]

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