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Old Mar 19, 2011, 12:14 PM
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2.4 GHz Antenna Placement

There is an excellent article by Sherman Knight on 2.4 GHz antenna placement in the April issue of R/C Soaring Digest, page 14. You can find it free online here. http://www.rcsoaringdigest.com/pdfs/...011-04Orig.pdf.

Anyone interested in optimizing their 2.4 GHz installation should read this article. Itís not just for sailplanes.

One of the authorís observations I found very interesting was the positive impact on fade count of ďusing the plastic tubes that come with the Spektrum 9300 receiver (or some other RF transparent tube).Ē

This tubing can be purchased as part of the Spectrum 2.4GHz Antenna Exit Guide [SPM6824] kit but there must be a generic source for this tubing.

Or would any tubing work?

What do you all think?

Louis
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Old Mar 19, 2011, 06:00 PM
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Originally Posted by Mathelo View Post
http://www.rcsoaringdigest.com/pdfs/...011-04Orig.pdf.
...
Anyone interested in optimizing their 2.4 GHz installation should read this article. Itís not just for sailplanes.
...
Louis
Thank you for the link. I have a similar follow-up question.

Does bending the "active" 31mm of the antenna reduce its effectiveness, and if so to what extent?

I'd imagine that puposefully scrunching up that little bit of wire into a tight ball would drastically cut down on its ability to "see" the signal, but that's no more than intuition. The author of the article shows the active portion of his antennae following a curved path through a plastic tube. Sure, the _length_ of the wire may still be 31mm overall, as it is in the reductio ad absurdum "scrunched ball" example, but the straight-line 31mm dimension is a thing of the past.

To what extent is it OK to bend the "active" 31mm?

Thanks
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Old Mar 28, 2011, 06:17 PM
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United States, WA, Redmond
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Not good to bend it.

For the tubing, I use teflon thin-wall. Of you use coax-based antennas, I strongly urge you not to cut the shielding yourself, but rather to buy replacements.. it is impossible to perfectly trim the shielding without damaging the inner wire unless you have the right tools.

My neighbor sells replacements on ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=280640661211

But I can also pick them up from you and send some over you want to pick some up on rcgroups.

P.S. The tubing that comes from spektrum is about 3 times too big... makes a huge hole in the fuse
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Old Mar 30, 2011, 07:09 PM
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Not good to bend it.

For the tubing, I use teflon thin-wall.
Where do you purchase the teflon thin-wall?

Louis
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Old Mar 30, 2011, 07:15 PM
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Where do you purchase the teflon thin-wall?

Louis
How much do you need? Mcmaster carr its around $1.70/ft... I bought in bulk, shoot me a pm for a better deal
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Old Feb 25, 2012, 10:41 PM
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Thanks for posting that article. I'm new to RC planes and just putting a Radian together with my own RX. From reading that article and the Futaba manual, I get that the most important part of the 2.4GHz wiring is the roughly 1.5" exposed portion of the wire. And my Futaba manual also seems to indicate that this portion of the wire, which they refer to as the "antenna" is to be as straight as possible. And that the two antenna's are to be 90 degrees to each other.
So the author of that article has some good info but he seems to be wrong in bending the antenna in its placement.
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Last edited by g725s; Feb 26, 2012 at 11:09 AM.
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