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SW, I recently posted a top hat model along with a bunch of other more conventional 1/4 wave ground plane antennas. I note the report below.

In this example of a variety of combinations using 102"/108" whips with suitable ground planes attached, and one model with no ground plane at all, including a top hat model I demonstrated the affects of the top hat using modeling. The Top Hat model did show a small increase in gain at the max angle of 33* degrees, and about the same as all other models @ the lower minor angled lobe at 9* degrees showing a gain of 3.33 dbi over real Earth... as modeled using Eznec5.

This gain and angle information does not provide a clue as to why a top hat antenna with an appreciable sized top hat element would seem to respond better to DX signals vs a radiator without a top hat, but if we look at the max angle pattern for these models we might see the clue as to why...please note the increased compression in the upper lobes area of the top hat model vs the similar area for all the other models listed.

In my real life experience while comparing antennas side by side I can, at times, actually sense this difference with DX responses as well. As I said before, this difference in response is not like a light switch difference, but it is detectable. So, something is going on with shortened radiators with top hats of a modest/large size compared to the wavelength.

[ATTACH]4480[/ATTACH]

<blockquote data-quote="Marconi" data-source="post: 275867" data-attributes="member: 903">SW, I recently posted a top hat model along with a bunch of other more conventional 1/4 wave ground plane antennas. I note the report below. &nbsp;In this example of a variety of combinations using 102&quot;/108&quot; whips with suitable ground planes attached, and one model with no ground plane at all, including a top hat model I demonstrated the affects of the top hat using modeling. The Top Hat model did show a small increase in gain at the max angle of 33* degrees, and about the same as all other models @ the lower minor angled lobe at 9* degrees showing a gain of 3.33 dbi over real Earth... as modeled using Eznec5. &nbsp;This gain and angle information does not provide a clue as to why a top hat antenna with an appreciable sized top hat element would seem to respond better to DX signals vs a radiator without a top hat, but if we look at the max angle pattern for these models we might see the clue as to why...please note the increased compression in the upper lobes area of the top hat model vs the similar area for all the other models listed.&nbsp;In my real life experience while comparing antennas side by side I can, at times, actually sense this difference with DX responses as well. As I said before, this difference in response is not like a light switch difference, but it is detectable. So, something is going on with shortened radiators with top hats of a modest/large size compared to the wavelength. &nbsp;[ATTACH]4480[/ATTACH]</blockquote>

[QUOTE="Marconi, post: 275867, member: 903"] SW, I recently posted a top hat model along with a bunch of other more conventional 1/4 wave ground plane antennas. I note the report below. In this example of a variety of combinations using 102"/108" whips with suitable ground planes attached, and one model with no ground plane at all, including a top hat model I demonstrated the affects of the top hat using modeling. The Top Hat model did show a small increase in gain at the max angle of 33* degrees, and about the same as all other models @ the lower minor angled lobe at 9* degrees showing a gain of 3.33 dbi over real Earth... as modeled using Eznec5. This gain and angle information does not provide a clue as to why a top hat antenna with an appreciable sized top hat element would seem to respond better to DX signals vs a radiator without a top hat, but if we look at the max angle pattern for these models we might see the clue as to why...please note the increased compression in the upper lobes area of the top hat model vs the similar area for all the other models listed. In my real life experience while comparing antennas side by side I can, at times, actually sense this difference with DX responses as well. As I said before, this difference in response is not like a light switch difference, but it is detectable. So, something is going on with shortened radiators with top hats of a modest/large size compared to the wavelength. [ATTACH]4480.vB[/ATTACH] [/QUOTE]

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