Double turnstile antenna

Hi!
I’m preparing to setup my own small SatNOGS station with a double turnstile antenna (for ~435 Mhz).

My main concern is the difference in schematics I see in the internet - some of them show both pair of dipoles connected to the cable - like this:

and some of them treat the second pair of dipoles as reflectors only - e.g. here:
435mhz-satellites-turnstile-antenna-tb1big
or here: https://iz7boj.wordpress.com/2018/12/02/double-turnstile-construction-for-satellites-receiving-in-435mhz-band/

Which design would be better? Any ideas/hints/experience would be appreciated! :slight_smile: Thank you in advance.

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For simplicity in construction I would probably go with option B… this is pretty much identical to the vinnant.sk design which works well.

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I also aggree with @vk5qi with the second option,as it is better explained on how this antenna must be built and it is simpler to build. More importanlty, the author of the antenna posted specific condsiderations for its building in order to achive an optimal SWR. http://www.radioamatoripeligni.it/i6ibe/turnhard/turnhard.htm

Unfortunately, this explanation is in Italian, but at least, it shows graphically how it must be built :slight_smile:

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Thank you! I’ll go for the second one and let you know about the results :slight_smile:

The first antenna has also a LHCP polarisation. Most satellies have RHCP polarisation as the second antenna have.

I’ve built the second one and the results are good. The SatNOGS station with this (second one) antenna is #804.

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Hi, I manage to build one and it works quite good!
Here is my station: https://network.satnogs.org/stations/588/

According to the NanoVNA it’s a little bit better on 400Mhz than on 435Mhz, but in my area there’s a lot of noise on these frequencies :< So 435-437 looks much better on waterfalls (it even managed to decode boot number from my KRAKsat, yay! :heart: https://network.satnogs.org/observations/3907042/)

I’m still waiting for the filter and LNA (now it’s without any of them) and I’ll probably make the station “normal” mode as soon as I get it (but it’s travelling from China, so :sweat_smile:)

I also plan to create a kind of tutorial “how to build it” with photos and schematics and post it on my blog, so I can let you know when it’s ready. Maybe someone will want to use it :slight_smile:

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Uploading: 2018910175711_2018715102322_Tuari.jpg…

All DIY versions is an I6IBE project scheme and working good in RHCP polarization
If someone need a kit of these turnstile can write me IZ5RZR@CATUREGLI.IT

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Finally wrote the article! :smiley: If you want to read it, it’s available here: https://alicja.space/blog/how-to-build-turnstile-antenna

Have fun building your antennas!

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