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Old Mar 19, 2011, 02:02 PM
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http://www.mwjournal.com/Journal/Com...tenna/AR_8587/

wouldn't this be a simpler solution?
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Old Mar 20, 2011, 12:31 AM
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Pico Rivera, CA
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Anyone know if these CP cloverleaf antennas work with the fatshark goggles? I just got a set of these but they dont work at all with the fatshark 5.8ghz. All i get is a black screen. The goggles work fine with the stock antennas. Im using the immersionRC 600mw TX.

The cloverleafs do work on my Iftron yellowjacket 5.8 RX
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Old Mar 20, 2011, 01:52 AM
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Quote:
Originally Posted by dimar View Post
http://www.mwjournal.com/Journal/Com...tenna/AR_8587/

wouldn't this be a simpler solution?
I found this statement in the description:

By using the gain comparison method, the measured gain of the proposed antenna is 0.2 dB.

0.2db "gain"... Well, antenna "gain" is usually compared to an imaginary idealized omni directional antenna that radiates like a ball evenly in all directions (that's where the "i" comes from with the unit dBi) or to a dipole with the former being the most often used. So this antenna would have five times less "gain" than basically no gain (1 dBi).....

I think almost everyone can make his/her cloverleaf with some practice and patience. The mentioned antenna uses PCB fabrication technologies and teflon substrate. I don't think that this would be easier for hobbyists.

The antenna has surely a potential in mobile handheld devices which are supposed to be rugged and mass produced.

Markus
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Old Mar 20, 2011, 11:10 AM
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Quote:
Originally Posted by teebok View Post
Anyone know if these CP cloverleaf antennas work with the fatshark goggles? I just got a set of these but they dont work at all with the fatshark 5.8ghz. All i get is a black screen. The goggles work fine with the stock antennas. Im using the immersionRC 600mw TX.

The cloverleafs do work on my Iftron yellowjacket 5.8 RX
My cloverleafs work fine on my 5.8 fatshark goggles. That seems like a rather odd problem...

On a side note, I finally had a chance to test them out at the field yesterday, and the experience was incredible! The increased confidence from using these antennas is just amazing - I couldn't get the smile off my face
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Old Mar 20, 2011, 11:40 AM
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Hmmm. Would one of these RHCP CL antennas work well on the VTX with a 15dB Yagi on the RX? (lawmate 1 watt system 1280mhz) or is some modification needed. OR will two CL's beat out the Yagi? Also can I diversify using two CL's on two receivers to get a better cross beam width for slightly less liner long range flights?
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Old Mar 20, 2011, 12:54 PM
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I am probably being a complete numpty here... so feel free to shoot me down in flames. The use of two or more receivers is fairly common place. I was wondering if it is possible to have two antenna's on the Tx side. My own obvious guess is no... for lots of reasons, not least of which would be how to join for arguments sake a clover leaf and an inverted v and not have the active element 'start' where the join is rather than the intended start of the active and ground. Is it possible to run to Vtx's on seperate frequencies - say 900 and 2.4 and have receiver diversity give you best at screen? Spent first spring day mowing lawns and tidying garden.... think the fresh air is confusing my nuerons

Paul
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Old Mar 20, 2011, 01:53 PM
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Hi guys,
a couple of pict of my CL and set up as promise.I have flown up to 1 km in all direction without any noise in the video.

Anthony.
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Old Mar 20, 2011, 02:04 PM
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Originally Posted by yogz View Post
I am probably being a complete numpty here... so feel free to shoot me down in flames. The use of two or more receivers is fairly common place. I was wondering if it is possible to have two antenna's on the Tx side. My own obvious guess is no... for lots of reasons, not least of which would be how to join for arguments sake a clover leaf and an inverted v and not have the active element 'start' where the join is rather than the intended start of the active and ground. Is it possible to run to Vtx's on seperate frequencies - say 900 and 2.4 and have receiver diversity give you best at screen? Spent first spring day mowing lawns and tidying garden.... think the fresh air is confusing my nuerons

Paul
You can use two TX antennas if properly coupled and phased appropriately, but generally this is a bad idea and I would not recommend trying it.

And using two frequencies is redundancy that is not needed. Just try a circularly polarized system and see what I mean. The last three crashes I had were running out of radio range because my video was rock solid the whole way. And my radio has been tested out over 2 miles and repeatedly has no trouble out that far. That should tell you something about the power of these antennas.

-Alex
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Old Mar 20, 2011, 02:05 PM
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Originally Posted by Rizzak View Post
Hmmm. Would one of these RHCP CL antennas work well on the VTX with a 15dB Yagi on the RX? (lawmate 1 watt system 1280mhz) or is some modification needed. OR will two CL's beat out the Yagi? Also can I diversify using two CL's on two receivers to get a better cross beam width for slightly less liner long range flights?
Use a CL and a helical. Forget the Yagi. Trust me, once you fly CP on both ends, you'll never look at that Yagi again.

-Alex
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Old Mar 20, 2011, 02:06 PM
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Originally Posted by Pipe Merchant View Post
My cloverleafs work fine on my 5.8 fatshark goggles. That seems like a rather odd problem...

On a side note, I finally had a chance to test them out at the field yesterday, and the experience was incredible! The increased confidence from using these antennas is just amazing - I couldn't get the smile off my face
What version Fatsharks are you using. Are they the V1 or V2? teebok is having trouble with his V2's and the CL antenna.

-Alex
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Old Mar 20, 2011, 05:29 PM
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Originally Posted by IBCrazy View Post
Use a CL and a helical. Forget the Yagi. Trust me, once you fly CP on both ends, you'll never look at that Yagi again.

-Alex
Thanks for your help. Im looking toward a 5 mile radius with moderate obstacles and varying altitude using DL for radio link. This shows how little i now about radios but would i be better with a ground level setup or putting the helical a 30 foot antenna mast?
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Old Mar 20, 2011, 09:34 PM
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Finally got around to finishing mine. These are the first antennas that I've ever built. They took a couple tries but i finally got it. Let me know if they look alright to you guys, I don't have a lot of experience with antennas.

Thanks,
Kyle D.
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Old Mar 21, 2011, 06:27 AM
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Your cloverleaf could use a little tweaking, but your skew-planar wheel looks exceptional!

I will release an update on this page on how to make the antenna bottom fed and much easier to construct. The way I designed mine was to be side fed and it makes it very difficult to build when feeding from the bottom. It appears most are bottom feeding theirs.

Actually, I made a video on how to do it. I just need to edit it.

-Alex
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Old Mar 21, 2011, 06:49 AM
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Alex,

Would these designs help at all on a ground vehicle? I'm looking to use a 500mW 900MHz Lawmate Tx on a Traxxas Summit and am wondering if this would maximize my chances of getting the best video possible.
Thanks!
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Old Mar 21, 2011, 07:52 AM
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Originally Posted by healthyfatboy View Post
Alex,

Would these designs help at all on a ground vehicle? I'm looking to use a 500mW 900MHz Lawmate Tx on a Traxxas Summit and am wondering if this would maximize my chances of getting the best video possible.
Thanks!
Sorry if I jump in to add my 2 here. CP antennas are advantageous in all scenarios where the target is to reduce reflections. Therefore I think it would be pretty advantageous for a ground vehicle. Clearly, the higher the frequency, the more the effect kicks in but 900Mhz is still high enough IMHO.

A HAM antenna book I'm having says that a vertical linearized antenna system suffers a 40!!! dBi loss when moving around in a forest, wheras a horizontally aligned antenna in the samme situation has a loss of ~12 dBi and a circular polarized one suffers only 3 dBi. I think this tells a lot.

Just my 2 though

Markus
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