Apparently it's a type of vertical (1' x 1' x 12').
Is there a reason to think this design is not included in the ARRL publications of the era
Ken, N2VIP
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On Feb 19, 2023, at 21:45, Joseph Wonoski via groups.io <N1KHB@...> wrote:
?What general type of antenna is it?
Joe n1khb
On Sun, Feb 19, 2023 at 9:39 PM, Samudra
<samudra.haque@...> wrote:
Hi,
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FT-817 QRP users, I am one of the developers of ?a modern incarnation of a very old design HF antenna (post WW2 apparently from the documentation I have) that was rediscovered/tested by other hams in the 70s-80s, and 90s. But then it was left alone AFAIK. We will soon have it on the air with my FT-817ND radio that I repaired a year plus ago, with the help of this forum members (Thank you). Our test cases will be SSB voice, and FT8 or other digital modes over a weekend coming up. Looking for regional contacts to try scheduled tests.
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In the DC/MD/VA region of US, I worked with a few business colleagues/ham radio operators to design/test/develop and fabricate working prototypes. Three versions are in testing now. What I am hoping is someone interested in antenna testing/fabrication will be able to indicate if what we are getting with an MFJ antenna analyzer and a MFJ antenna tuner (all we have in the field, but I have more equipment in my RF test lab ¨C not at the placed where the antenna is being fielded) is good or not:
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3.750 MHz ~ 1.0-1.1 SWR
7.010 MHz ~ 1.1-1.2 SWR
14.200~250 MHz ¨C 1.3 SWR
¡
28 MHz ¨C 1.2x SWR
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These were the first trials, with the fully assembled kit about 6 feet a.g.l. Total dimension is approximately: 1ft x 1ft x 12ft. It¡¯s a geometrically complex antenna design, that hurts most antenna analyzing software. We haven¡¯t got the lifting system in place to erect it safely to about 20 feet a.g.l. so this is the best we can do for now.
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Any comments on the statistics I am presenting welcome. I was not expecting so low SWR and we haven¡¯t tried with a live transceiver yet. But there are very distinct notches and our dimensions of the radiation region was even bang on from antenna modeling theory with some margin. Feeder was a 50 ohm coax to manual antenna tuner unit of about 25ft length.
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We are wondering if it would be interesting to any with small space for antennas? What are your thoughts and requirements on packaging/support/reliability ? It¡¯s becoming a challenge to source all parts at low cost and yet have good manufacturability and repeatability with the complex measurements mechanical and electrical per the design.
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73 de N3RDX
Washington, DC
