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New Italy's Collinear Antenna for 27 mhz 10,40 meter lenght

Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
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Marconi got me thinking... I didnt remember i gave it a name...
But i did remember the "saturn" (the bi-square antenna).
So i was thinking Mercury ? jupiter?
After an hour it came back hi... "Highlander" it was.
"Highlander" that is it.

Thanks
 
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The DB

Sr. Member
Aug 14, 2011
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Diagrammi_GMAX.jpg

That radiation pattern reminds me of some of the vector models from back in the day. Its not exact, but I recall some of my models having little to no high angle radiation, and most of said radiation was in a low angle lobe. And it wasn't every model, just some of them.

The shown current/phase distribution confuses me. It is very unexpected, at least compared to how I would design/build such an antenna. Many questions appear in my head about this part alone, although I want to put some more thought into it first. I do find it highly unusual that the lower 1/4 wavelength section isn't completely in phase with itself, and carries the same amount of out of phase currents as the 5/8 wavelength element above? For a collinear design this is at best highly unusual. I would also ask, at first glance, are the radials shorter than the vertical 1/4 wavelength element? I wonder if these two things factor in to create some form of matching?

I wish I had more time to play with modeling at the moment.

I'm not seeing them listed here, but did we ever get the dimensions of this antenna? The inductance of that phasing coil would also help.


The DB
 
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Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,101
2,109
343
Houston
DB when you get some time try this for dimensions on YouTube. I could not get the link to work, so Cut this title below and Paste it to YT. Might be on top of list.

GRAZIOLI G-MAX.....unboxing & montaggio​


You can set Video to English, but the English is not that good, just get dimensions off the measuring tape he used. Measurements start at 27 minutes into video, and you will see the 3 important overall dimensions on the tape.

Important note.
I also think the black mark on the tubing is the location of a guy wire bracket at the base of the antenna top section of the radiator and is maybe 5" inches long. This is where the bottom and top sections overlap and connect.

He also writes down that 27.500 MHz is his center frequency so these dimensions will likely be short, compared to CB. See this at 19 minutes.

Manual is below:

 

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  • IM005R0_Grazioli_G-Max_MANUAL (1) (3) (5).pdf
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Marconi

Usually if I can hear em' I can talk to em'.
Oct 23, 2005
7,101
2,109
343
Houston
I would also ask, at first glance, are the radials shorter than the vertical 1/4 wavelength element? I wonder if these two things factor in to create some form of matching?
Yes, the radials are 106" and note manual says they are the same at all frequencies.
 
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