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I found one reference to the DDRR antenna, on W8JI's Website, in this very long report near the bottom, at this link.
https://www.w8ji.com/mobile_and_loaded_antenna.htm

I used this Microsoft tool. Simultaneously type CTRL F keys to open the function to scan this long document, in case you want to try it. Open the document and then open this tool, and just enter a word or phrase into the proper field. AFAIK, this will scan any real text document.

Below is the comment, so you don't have to read the whole report trying to find the reference.

"Radiation resistance of a Marconi vertical in the maximum possible radiation resistance case for a given height (this is the case where current is uniform throughout the structure) is equal to 1580*(H/L)^2 where H equals height and L equals wavelength and both are expressed in the same units. Using degrees, we see a 10-degree tall antenna has a maximum possible radiation resistance of 1580*(10/360)^2 or 1580*.000772 = 1.22 ohms. This would apply even if the antenna is a vertical, DDRR, Fractal, or folded unipole with considerable top loading."

<blockquote data-quote="Marconi" data-source="post: 680843" data-attributes="member: 903">I found one reference to the DDRR antenna, on W8JI&#039;s Website, in this very long report near the bottom, at this link.<a href="https://www.w8ji.com/mobile_and_loaded_antenna.htm" target="_blank">https://www.w8ji.com/mobile_and_loaded_antenna.htm</a>I used this Microsoft tool. Simultaneously type CTRL F keys to open the function to scan this long document, in case you want to try it. Open the document and then open this tool, and just enter a word or phrase into the proper field. AFAIK, this will scan any real text document.Below is the comment, so you don&#039;t have to read the whole report trying to find the reference.&quot;Radiation resistance of a Marconi vertical in the maximum possible radiation resistance case for a given height (this is the case where current is uniform throughout the structure) is equal to 1580*(H/L)^2 where H equals height and L equals wavelength and both are expressed in the same units. Using degrees, we see a 10-degree tall antenna has a maximum possible radiation resistance of 1580*(10/360)^2 or 1580*.000772 = 1.22 ohms. This would apply even if the antenna is a vertical, DDRR, Fractal, or folded unipole with considerable top loading.&quot;</blockquote>

[QUOTE="Marconi, post: 680843, member: 903"] I found one reference to the DDRR antenna, on W8JI's Website, in this very long report near the bottom, at this link. [B][URL]https://www.w8ji.com/mobile_and_loaded_antenna.htm[/URL][/B] I used this Microsoft tool. Simultaneously type [SIZE=6][B]CTRL F[/B][/SIZE] keys to open the function to scan this long document, in case you want to try it. Open the document and then open this tool, and just enter a word or phrase into the proper field. AFAIK, this will scan any real text document. Below is the comment, so you don't have to read the whole report trying to find the reference. "Radiation resistance of a Marconi vertical in the maximum possible radiation resistance case for a given height (this is the case where current is uniform throughout the structure) is equal to 1580*(H/L)^2 where H equals height and L equals wavelength and both are expressed in the same units. Using degrees, we see a 10-degree tall antenna has a maximum possible radiation resistance of 1580*(10/360)^2 or 1580*.000772 = 1.22 ohms. This would apply even if the antenna is a vertical, [SIZE=6][B]DDRR[/B][/SIZE], Fractal, or folded unipole with considerable top loading." [/QUOTE]

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