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Thanks for the tests Thomas.

But remember most important of all factors, this one is circular polarized !! so there is no holes to be seen when rotated !!

this is what we like when using it to receive RC video from a plane in any angle.

What was the lowest and highest signal recorded when rotated ?

I would also be interested in what you could find out about the luxl type of patch that Lupy made. http://www.rc-cam.com/forum/index.php?show...opic=1640&st=40

Terry

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>I would also be interested in what you could find out about the luxl type of patch that Lupy made

you pay and send one to me, then I will be happy to measure it and compare it.

all those field tests and compare using planes and pictures on a screen or video recording is close to useless if you ask me. it is impossible to prove anything accurate and reproduseable. you can not say how many dB better or worse, it will very easly be a personal matter of opinion, and I dont like that.

it is the same as saying my own selv made patch is better, bla bla,

see my measurements and see how many dB gain it perform, and eod.

>What was the lowest and highest signal recorded when rotated ?

only 5-10dB, the other patches gives 17-30dB futher attenuation when rotated !

so there is a huge differnce here.

Edited by ThomasScherrer

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you pay and send one to me, then I will be happy to measure it and compare it.

If I could get it to work myself I would not need you to look into it. :rolleyes:

When I have more time I am sure I can get it to work but it may take me a while as I have other stuff to do first. :P

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yes terry, but how can you fly exactly the same pattern in same angle and same distance to prove one antenna is 2dB better ?

and how can it be dublicated and verified ?

you are right about engineers with cool measure tools,

they normally dont belive it if it can not be mesured :-)

the things I made can be reprodused, repeated by anyone else, so we can compare results worldwide to the last dB, the result will be better results for us all,

that is all im am trying to help with.

I could make the antenna you mention, if I could get digital drawings with measure verify numbers on them, or gerber files or such.

but you see if I have 0.5mm more or less space or size, the center frequency or match will move 100-200MHz, so I need to know it all, else the measure results will not justify a maybe cool design.

Remember the goofprof Patch could be improved several dB just by changing some sizes a few mm. the original was good, but could be even better.

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I suspect discussion boards like this are interesting precisely because of the contrast between the quantitative information (specs - mW, dB, polar diagrams etc.) provided with Txs, Rxs, antennae etc., and the qualitative information that comes from experience of using stuff in the field. Call me a cynic, but these days I'm only impressed by (reproducible) differences in specification as post hoc explanations of qualitative differences in what I see in the field!

Having said that, I'd be interested in a bit more "fuzzy but quantitative" data on our qualitative experiences. Things like 'typical dropouts per minute' for a series of flights with a given setup, or 'distance at which the picture starts to fuzz up'. Sure, these will vary a lot with equipment, installation, weather and setting - but as long as this is all recorded, it is useful information for anyone trying to optimised their own gear.

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I love this, where else can you talk this stuff out :D

yes terry, but how can you fly exactly the same pattern in same angle and same distance to prove one antenna is 2dB better ?

and how can it be dublicated and verified ?

OK, first off I must say that I don't fly anything with my initial testing, my normal practice is to set up my TX on a tripod and then walk away from it with my RX and aerial under test and see where the signal is lost. I always use the same places in the same field to set up so I get a very quick idea of if the aerial is performing as expected. After the aerial under test is checked I then confirm my results by doing the same test with my known aerials ( dipole, 8dbi patch and 14dbi patch). The actual dbi numbers dont mean much to me as I am more interested in how the aerial relate to each other, the claimed gain only gives me an idea of what to expect.

The 2db better you talk about would show up as maybe 20metres past my last aerial. ;)

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I like to see both sides :)

The hard data from Thomas is great, but i dont really understand it all or the implications of each dB gained. I'm a software developer not a wireless engineer :).

Terry and Dennis (btw, anyone seen him recently?) come up with some very interesting observations. They are not precise, but to me (the idiot) they are more useful. Them saying "Well i really liked this one, i got a better picture and went as far as i dared without getting any dropout. I have not been able to do this before" makes me want to look at that product over the one they were testing before.

Now what i really like is when we get Thomas *and* other peoples opinion on things and how well they work. That way i can really see how the dB gain is improving the antenna. I found out before that dB gain isn't everything when i got my 16dBi patch antenna. Loads of gain - but so directional it was almost impossible to keep pointed at the plane (a very slow moving glider). So the 16dBi patch shows up better on the hard test, but the opinion of users of it leave alot to be desired.

However, if i could read the graphs and radiation patterns on the 16dBi i probably would have expected that :P. But again, i'm just the average joe when it comes to this stuff, not a wireless engineer ;)

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I like to see both sides :)

The hard data from Thomas is great, but i dont really understand it all or the implications of each dB gained. I'm a software developer not a wireless engineer :).

Terry and Dennis (btw, anyone seen him recently?) come up with some very interesting observations. They are not precise, but to me (the idiot) they are more useful. Them saying "Well i really liked this one, i got a better picture and went as far as i dared without getting any dropout. I have not been able to do this before" makes me want to look at that product over the one they were testing before.

Now what i really like is when we get Thomas *and* other peoples opinion on things and how well they work. That way i can really see how the dB gain is improving the antenna. I found out before that dB gain isn't everything when i got my 16dBi patch antenna. Loads of gain - but so directional it was almost impossible to keep pointed at the plane (a very slow moving glider). So the 16dBi patch shows up better on the hard test, but the opinion of users of it leave alot to be desired.

However, if i could read the graphs and radiation patterns on the 16dBi i probably would have expected that :P. But again, i'm just the average joe when it comes to this stuff, not a wireless engineer ;)

I've just picked up 12dbi omni directional antenna.. more like a plastic pole ( also makes a great Asian martial art weapon! Bo-Kata anyone?) I love to share my test results here today but the my left SP400 brushed motor decided to flash in mid air lastweek. My friend thought I had flashing LED's onboard my plane.... Nope it was just the left motor sparking up a little light show! :o

Going BL motors next with the great guidance of Thomas & Kilrah! :D

Mark: you are right about those patch antenna... very nearrow beam so very directional. I hope I'm doing the right thing for me by choosing a larger omni directional, if not oh well I can still use it for other purposes in my buisness.

I'll most likely share my experince with this omni directional antenna once I get my Twinstar up and flying. ;)

When you say," Dennis (btw, anyone seen him recently?) That is what you meant right? Well he has been quiet lately. Perhaps still mourning his loss of his Easystar? Or perhaps wayyyy too busy constructing a fleet of FPV planes! :lol:

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He's probably plotting to take over the world 

No......He already did that last year :lol:

Terry

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my experiance with omnis like you are talking about, is that they are omni only in a flat plane. If you are above or below the plane, then reception is very poor.

If you already have it, it's worth a try though.

Thomas, I am looking around to see if there is any more of the blue circuit board I used on the first one. If I can make annother that works, I will see about sending you one. I have posted the specs for both the orig and my copy, my copy is a little smaller on the collector dia (2.35" dia) vs(2.4" for the orig) , but everything else seems to be the same. I am hesitiant to send my only one, just incase it is lost, and I can't repeat it.

I am curious if you have the gear to do beam width testing? The testing you did on the GPP is interesting, but dosn't address that point. At least for our pourposes, a highly efficent highly directional antenna is very different fom a wide angle one.

Thanks for your contribution so far.

Ken

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YES, I have also access to a full beam measurement station, it is automatic, and can do 2 axis plus rotation,

we have it all here at my work, we also design antennas for Tetra and GSM :-)

the only thing that will be interesting is the pickup antenna how well it handle 2.4 since it is only rated to 2GHz, the pickup parabol is over 3 meters :-)

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