Regarding Observation 3485146 …
first listen in the snow … no attenuation of the signal at first sight
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Hi michel, I am interested in Sinuous antenna for SATNOGS. Not much information anywhere, do you happen to have a building/cutting/tuning instructions by any chance? Thank you.
Andriy
W9KM
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I’ve cutting antenna with laser in 2 mm aluminium sheet.
sinous-antenna.dxf.txt (156.0 KB)
rename file to .dxf
I’ve not tested self-complimentary antenna (slot antenna) with balun, next step…
Documentation :
edir301.pdf (1.6 MB)
My version is cutting for 100 MHz to 2 GHz, diameter : 1,27 meter
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How are you feeding this antenna? With the tapered balun mentioned in the paper, or something else?
Also, if I’m reading that DXF file correctly, that antenna is ~1.2m in diameter?
For the moment impedance is not adapted, the two pairs of arms are in parallel (133 ohms each pair of arms => 66.5 ohms in parallel) followed by a 75 ohm coaxial cable then the key SDR at 50 ohms. Despite this mismatch, the result is better than my old biconical antenna.
The following concerns the fabrication of a wideband balun to adapt the normal antenna (133 ohms) and the slit antenna (266 ohms) with 4 receivers to make beamforming.