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Old May 18, 2011, 01:16 PM
Fly like never crash as always
tascheri's Avatar
Rio de Janeiro
Joined Mar 2007
275 Posts
Finally took a deep breath and jumped on it. Took me less than 1 hour to do my first and I fumbled a lot to solder in order to get it perfect.

RHCP, right?

I donīt bank a lot with my EZ ( at least when Iīm far away ), thatīs why I chose this one for the aerial.


My immediate intentions are to cover my GP patch reflector corner and use it with this one.

sanity check someone??



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Old May 18, 2011, 01:20 PM
ysb
use the force..or a quadcopter
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quebec
Joined Dec 2010
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Quote:
Originally Posted by cncoz View Post
For what It's worth...
I made a set of CP's for my 5.8Ghz parkflier, hope to try them tomorrow.
I worked this template out to help with bending, might be useful to someone.
If the antennae perform well I'll post pics.
Cheers !
thanks i will check my Cloverleaf on this template
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Old May 18, 2011, 01:42 PM
Oh so close!
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Campbell River
Joined Jan 2010
702 Posts
Use this for my router?

Sorry to go off-topic for a second.

If I build a 2.4ghz version and modify my stock whip antenna that came with my router would I get better range? I'm over a my neighbours place a lot and get spotty reception. Maybe this might help? If I do build one just orient it so it is facing up?

cheers
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Old May 18, 2011, 02:28 PM
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Quote:
Originally Posted by clipper99 View Post
Sorry to go off-topic for a second.

If I build a 2.4ghz version and modify my stock whip antenna that came with my router would I get better range? I'm over a my neighbours place a lot and get spotty reception. Maybe this might help? If I do build one just orient it so it is facing up?

cheers
It's hard to say. My first though is probably not. However a 3/2 wave dipole would do pretty well.

-Alex
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Old May 18, 2011, 02:29 PM
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Quote:
Originally Posted by tascheri View Post
Finally took a deep breath and jumped on it. Took me less than 1 hour to do my first and I fumbled a lot to solder in order to get it perfect.

RHCP, right?

I donīt bank a lot with my EZ ( at least when Iīm far away ), thatīs why I chose this one for the aerial.


My immediate intentions are to cover my GP patch reflector corner and use it with this one.

sanity check someone??



That looks pretty good to me. I see you reversed you GP patch panel like I suggested. Watch how clean your video is now.

-Alex
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Old May 18, 2011, 03:05 PM
Fly like never crash as always
tascheri's Avatar
Rio de Janeiro
Joined Mar 2007
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Quote:
Originally Posted by IBCrazy View Post
That looks pretty good to me. I see you reversed you GP patch panel like I suggested. Watch how clean your video is now.

-Alex
thx buddy! Rain is fading and the weekend is going to rock!! too bad my GS DVR had to be returned and I wonīt be able to share video.

in fact I had built the GP like that from the beginning, I didnīt go back to look at pictures after I printed the template and it just came out like that.

BTW, Iīm using aluminum panels with small tin squares riveted to it ( thatīs where I solder the connections ). Do you see any issues?? Should I still cover the dog ear on the reflector or just test it like that??

sorry to bother you again.
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Old May 18, 2011, 09:22 PM
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I think you'll be ok with it how it is. The GP patch is a copy of K5OE's dual band patch for dish feed which was designed back in the 1950's. The trimming of the corners was to allow the second patch to radiate at the fringes.

-Alex
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Old May 21, 2011, 09:50 AM
Fly like never crash as always
tascheri's Avatar
Rio de Janeiro
Joined Mar 2007
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Alex, your really got me... best video ever... I took my vee to compare but I never bothered to even mount it. the static is less than seldom. Lost signal behind a mountain but I was really pushing it low on the other side...just eased on the elevator and signal came back in less than a second. got some static flying 3 meters high and 200 meters away but right in the beam of a very big cell phone mast. flew a mile upwind with absolutely no degradation.

Almost lost my plane today... I did a very stupid thing, my Video Bat + wire got loose of the connector so I flew off the charging connector... It was good down to 10.9 volts... but then.... just lost it completely in a flash... I was 600 m away and donīt ask me how I spotted it because I donīt know... My 2 spotters only saw it when I was like 200 m away..
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Old May 21, 2011, 10:39 AM
la fabrique circulaire
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geneva
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my Skew-Planar

if you want more detail about building, it is here

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Old May 21, 2011, 10:44 PM
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I just bought one of these from RMRC, a set with the cloverleaf. I have the inverted vee on my plane, and I'm going to use this with my Eagle Eyes diversity feature.

I'll try this first, then the cloverleaf and see how much difference there is.

I just modified my ground station last night, here it is with the mods:
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Old May 22, 2011, 08:23 PM
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Put the cloverleaf on the plane and forget the Vee. There is hardly any comparison. It's that good

-Alex
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Old May 22, 2011, 09:12 PM
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Quote:
Originally Posted by IBCrazy View Post
Put the cloverleaf on the plane and forget the Vee. There is hardly any comparison. It's that good

-Alex
I was thinking about that, but I thought you mentioned one other time the Vee might be better for when I dip below the treeline.

My Cloverleaf is the blubeam without the cable, so should I just turn the tx where it is and stick it on there? (see pic's) Or should I put it up front just behind the prop, which is the highest point on the plane.
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Old May 23, 2011, 04:42 AM
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Can I use 1.1mm thickness galvanized steel to build this antenna (and the cloverleaf) for 1280mhz?

thanks
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Old May 23, 2011, 07:32 AM
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Quote:
Originally Posted by Glenstr View Post
I was thinking about that, but I thought you mentioned one other time the Vee might be better for when I dip below the treeline.

My Cloverleaf is the blubeam without the cable, so should I just turn the tx where it is and stick it on there? (see pic's) Or should I put it up front just behind the prop, which is the highest point on the plane.
The Vee/Biquad will do better when dipping behind trees, but in general the CL/SPW is the absolute best antenna combination you can fly.
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Old May 23, 2011, 07:33 AM
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Quote:
Originally Posted by datyip View Post
Can I use 1.1mm thickness galvanized steel to build this antenna (and the cloverleaf) for 1280mhz?

thanks
You meant the patch? yes. The Skew-wheel and cloverleaf? If it's 1.1mm wire, yes. I never thought about it, but bailing wire would probably work fine for this antenna too.

-Alex
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Old May 23, 2011, 07:57 AM
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Quote:
Originally Posted by IBCrazy View Post
You meant the patch? yes. The Skew-wheel and cloverleaf? If it's 1.1mm wire, yes. I never thought about it, but bailing wire would probably work fine for this antenna too.

-Alex
Sorry for not being clear.

I'm referring to the wire for building the spw/cloverleaf..
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Old May 23, 2011, 09:02 AM
Whats the wrst that can happn?
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Joined May 2010
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Hey is there anyway to go CP with UHF 433mhz Rx/Tx's. I imagine the Rx antennas would be to large, but is there a way around that?

I've been getting bad multipathing on the Tx/Rx flying in the city but don't know of a better solution. The signal will just drop out completely in a matter of 2-3 seconds! It can't be a null because the Tx is an omni whip and I'm no where near the top end null (out 4000 feet and maybe 600ft up) and I'm not far enough out to be losing the signal (4000 ft LOS using a Scherrer LR UHF on the 2w setting). The Rx antennas are positioned in an "L" shape on either side of the Skywalker nose). And I don't think this is from RF because it's happened in two totally separate locations in the city.
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Old May 23, 2011, 09:42 AM
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Yes: turnstile antenna. It is circularly polarized.
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Old May 23, 2011, 09:45 AM
Whats the wrst that can happn?
AdamChicago's Avatar
Chicago, IL USA
Joined May 2010
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Oh I didn't realize it was a CP. What would be a good Tx CP mate for it? I imagine the stock omni whip (even when tilted on its side) wouldn't be as good as a CP antenna?

Quote:
Originally Posted by IBCrazy View Post
Yes: turnstile antenna. It is circularly polarized.
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Old May 23, 2011, 09:52 AM
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I'm not sure if I'd use it as a TX antenna or an RX antenna. An RX antenna might be easier to mount. Eiher way, it should help with some of your problems. multipathing shouldn't be too bad for a control system unless you are flying very low to the ground.

-Alex
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Old May 23, 2011, 10:11 AM
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Thanks for your answer. Do I have to adjust the measurements or can I use directly your formulas in order to use the galv steel wire?

Quote:
Originally Posted by IBCrazy View Post
You meant the patch? yes. The Skew-wheel and cloverleaf? If it's 1.1mm wire, yes. I never thought about it, but bailing wire would probably work fine for this antenna too.

-Alex
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Old May 23, 2011, 10:58 AM
Don't disturb the pilot !!!
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Canada, QC, Quebec
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Alex, saw this post from Sander ? Maybe it's the reason why the cp antennas don't work with the Lawmate Rx ??

http://www.rcgroups.com/forums/showp...postcount=1422
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Old May 23, 2011, 12:19 PM
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Quote:
Alex, saw this post from Sander ? Maybe it's the reason why the cp antennas don't work with the Lawmate Rx ??
They do work, install a 100ohm resistor between video and ground on the vtx side.
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Old May 23, 2011, 02:45 PM
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Hugo, you use a 100pF capacitor in series with the antenna centre connection to block the DC flow.

Nigel.
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Old May 23, 2011, 03:01 PM
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Quote:
Originally Posted by saucisse View Post
Alex, saw this post from Sander ? Maybe it's the reason why the cp antennas don't work with the Lawmate Rx ??

http://www.rcgroups.com/forums/showp...postcount=1422
Gee, I can't believe this internet rumor is still circulating. The Facts are:

1) Lawmate Rx work fine with CP antennas. I have six lawmate RX and they all work perfectly with CP antennas and all other antennas I have tried.

2) Sander's post was a speculative response about what could be the problem if there was a problem (but there really is no problem). He thought the Lawmate RX might have +5v on the antenna output to power an external LNA which could be shorted if a closed loop antenna was used. This is an easy test to make: test the antenna input of the Lawmate with a voltmeter. You will find there is no DC voltage there.

What typically happens is that someone has a problem with their system or testing approach, blames a particular component and then makes a post. I know that facts have little impact on beating down internet rumors but I can't resist trying.

OMM
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Old May 23, 2011, 03:10 PM
Don't disturb the pilot !!!
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Canada, QC, Quebec
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Sorry if my comment bugged you out that much! I don't read all post in here

Quote:
Originally Posted by Old Man Mike View Post
Gee, I can't believe this internet rumor is still circulating. The Facts are:

1) Lawmate Rx work fine with CP antennas. I have six lawmate RX and they all work perfectly with CP antennas and all other antennas I have tried.

2) Sander's post was a speculative response about what could be the problem if there was a problem (but there really is no problem). He thought the Lawmate RX might have +5v on the antenna output to power an external LNA which could be shorted if a closed loop antenna was used. This is an easy test to make: test the antenna input of the Lawmate with a voltmeter. You will find there is no DC voltage there.

What typically happens is that someone has a problem with their system or testing approach, blames a particular component and then makes a post. I know that facts have little impact on beating down internet rumors but I can't resist trying.

OMM
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Old May 23, 2011, 03:34 PM
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Low range

Hi there

i've build one of those Skew Planar Wheel for my 910Mhz 800mw Hobbyking RX/TX Set but the result is extremely bad.

Though i tried to keep tolerances as small as somehow possible (<= 1-2mm) it does not give me more than 200m of range in direct line of sight. Tried all channels 1-4 (910-1040 MhZ) and channel 3 ist best. The Standard antennas even give me slighly more range and more robust signal. Any Idea what might be wrong?

Here's a pic of my two antennas:


P.S: 900M Mhz is the primary band for cellphones right over here. Might this affect the range that much? Cellphones are allowed to send 2W .... basestations about 8W.
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Old May 23, 2011, 05:15 PM
QiW
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south east asia
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hi
i am using the hobbyking 200mW 900mW system ... and the cells in my country operates on GSM which is also around the 900mhz area
i am using the cloverleaf on my vtx and SPW on my vrx ... so far my signal has been good up to 700m or thereabouts (checked on goggle map)... cannot fly far yet as i do not have RTH and OSD (but they are on the way) ... i have even flown my plane to within 100m of a cell tower with mild interference and between trees too
in theory u should have at least double my range
i see u have the SPW on both vrx and vtx ... u might wanna give the CL a try on your vtx since this combo is highly recommended
there was one time when i was getting no more than 200m of range so i did some checking ... apparently one of the wires have a cold solder joint on my vtx and cracked on the solder breaking up the signal intermittently ... making the range much much shorter than it should be ... u should try checking the solder points on your vtx/vrx just in case
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Old May 23, 2011, 05:16 PM
Future-proof EVERYTHING
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If your in Europe or another country using GSM, I wouldn't use 900 mhz.. The cell towers can and likely will trash the signal if you get in their beam.
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Old May 23, 2011, 07:07 PM
QiW
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south east asia
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hi darkheli
i have set my vtx closer to 1ghz ... so far the gsm 900mhz has not really affected me seriously ... unless i fly really close to the tower(s)
yes ... i know its a bad idea/choice of frequencies on my part
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Old May 23, 2011, 10:46 PM
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Quote:
Originally Posted by careyer View Post
Hi there

i've build one of those Skew Planar Wheel for my 910Mhz 800mw Hobbyking RX/TX Set but the result is extremely bad. ...
That antenna looks too small for 910 Mhz, more like a 1280 Mhz antenna. What dimensions did you use?

OMM
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Old May 24, 2011, 12:07 AM
QiW
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hi OMM ...
if the rx casing is anything to go by (i assume they are the same size as mine) then his antenna size looks about the same as mine
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Old May 24, 2011, 11:12 AM
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Quote:
Originally Posted by careyer View Post
Hi there

i've build one of those Skew Planar Wheel for my 910Mhz 800mw Hobbyking RX/TX Set but the result is extremely bad.

Though i tried to keep tolerances as small as somehow possible (<= 1-2mm) it does not give me more than 200m of range in direct line of sight. Tried all channels 1-4 (910-1040 MhZ) and channel 3 ist best. The Standard antennas even give me slighly more range and more robust signal. Any Idea what might be wrong?

Here's a pic of my two antennas:


P.S: 900M Mhz is the primary band for cellphones right over here. Might this affect the range that much? Cellphones are allowed to send 2W .... basestations about 8W.
I have a hard time seeing from the picture, but it looks to me like one is LHCP and the other is RHCP. The interactions between these antennas will be -18 db or so if this is the case.

-Alex
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Old May 24, 2011, 11:58 AM
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...
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Old May 24, 2011, 02:55 PM
la fabrique circulaire
terry74's Avatar
geneva
Joined Jan 2008
550 Posts
just to post also here and say that the "magic combo" CP/SPW work like no other antenna....

CL and SPW antenna on my DIY Delta FPV wing (11 min 43 sec)


is this the future standard antenna in FPV ?

yes with no doubt


Jay
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Old May 26, 2011, 02:12 AM
QiW
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south east asia
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i am currently running 900mhz SPW on my vrx
to prevent wire clutter around myself ... i have gotten a FOXTECH AIO with built in 5.8 vrx
i then placed a 25mW 5.8vtx to relay the video from my 900mhz system to my goggles

question ...
how would performance compare if i just place the 900 CL on a tripod on the ground vs tripod on the roof of my car/van ?
the height of the tripod would be about 5ft or so
my current fly field is asphalt car park with buildings with some curve and flat metal roofs but these buildings are nothing higher than 3-4 storeys

thanks ...
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Old May 26, 2011, 06:36 AM
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On the ground would be better. Eventhough the Cloverleaf/SPW reject multipath well, placing it on a huge metal reflector will still hurt performance.

-Alex
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Old May 26, 2011, 07:18 AM
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Quote:
Originally Posted by IBCrazy View Post
On the ground would be better. Eventhough the Cloverleaf/SPW reject multipath well, placing it on a huge metal reflector will still hurt performance.

-Alex
Not sure i agree Alex.

I have my VRX mounted on a tripod that stands on the roof of my van; 1.2m higher than the roof. I have also tried with the tripod on the ground and have to say it seemed better on the roof.

I have been led to belive that omni antennas work best when they are mounted up as high as possible (up to a point) and this does seem to be the case with my CL, SPW combo.

You can see my setup at the end of this vid (4:52); only close in flying in this clip but i have been out to near my 35MHz range limit and the video was still great

FPV on the beach (5 min 28 sec)
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Old May 26, 2011, 08:30 AM
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A stand on the roof is fine, but on the ground is better. Well, assuming the Fresnel zone is clear. I guess I figured that there would be no objects he'd be flying over that would disturb the Fresnel zone.


-Alex
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Old May 26, 2011, 08:44 AM
QiW
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i will try both this weekend and let u guys know
there is also a telco GSM 900/1800 200m from where i stand .. hehehehe
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Old May 26, 2011, 04:17 PM
FPV from Lithuania
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Lithuania
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Alex, can i put SPW in plastic case with 1mm wall thickness? 5.8Ghz 200mW. I want to build compact ground station and dont want to brake a SPW antenna, so i need to put it in plastic case.
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Old May 27, 2011, 07:50 AM
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Alex, can i put SPW in plastic case with 1mm wall thickness? 5.8Ghz 200mW. I want to build compact ground station and dont want to brake a SPW antenna, so i need to put it in plastic case.
Yes.
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Old May 27, 2011, 01:24 PM
Future-proof EVERYTHING
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Spw

How does my SPW look? @ 1280 RH polarized
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Old May 27, 2011, 03:13 PM
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lobes are not angled vertically enough & you need to pull them around so there's a more even overlap.

otherwise good.
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Old May 27, 2011, 08:12 PM
Oh so close!
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Campbell River
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Originally Posted by Toysrme View Post
lobes are not angled vertically enough & you need to pull them around so there's a more even overlap.

otherwise good.
Man you got some mad ability for spacial visualization in your brain! I've only built 2 5.8ghz SPW's and it looks like he's got his 45 degrees going on to me but anything other than an oblique angle and it gets hard for me to tell either way!

Cheers
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Old May 27, 2011, 11:06 PM
QiW
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Quote:
Originally Posted by QiW View Post
i will try both this weekend and let u guys know
there is also a telco GSM 900/1800 200m from where i stand .. hehehehe
tested on car roof and on asphalt ground this morning ..
overall height from ground using tripod alone was 5ft
overall height on the roof of the car was around 7.5ft (i shortened the tripod legs when on the roof)

at higher altitudes ... the ground and roof version performed about the same
but at lower heights the roof version seemed better marginally .. lower = 10-20ft weaving around small trees and lamp posts (in a cloudsfly .. hehehe)

i also noticed when i/plane fly over greens/grass/trees ... signal is much better than when over roads .. high metal content in the asphalt/tar road construction in my country ??
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Old May 28, 2011, 12:22 PM
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Bangkok
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Alright, I'm going to build one this weekend to use with a 5.8Ghz transmitter.

I just tested and it turns out that it's actually very easy to solder an electric guitar steel wire, so I'm going to use that for the antenna.

One thing I'm not quite sure though. For the receiver end, should I make an identical antenna or is it better to use a different model?
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Old May 28, 2011, 12:29 PM
Oh so close!
clipper99's Avatar
Campbell River
Joined Jan 2010
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The recommended antenna for the TX is the circular polarized antenna and the SPW is for the RX.

http://www.rcgroups.com/forums/showthread.php?t=1388264

Have fun!
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Old May 28, 2011, 01:49 PM
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Bangkok
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Quote:
Originally Posted by clipper99 View Post
The recommended antenna for the TX is the circular polarized antenna and the SPW is for the RX.

http://www.rcgroups.com/forums/showthread.php?t=1388264

Have fun!
Ah yes. I'm reading up on that.

Another question, I'm planning to mount the SPW Tx antenna upside down in the fuselage in a small bulge under the nose, which if I'm not mistaken would switch the polarization. So, should I make a left hand SPW and a right hand Cloverleaf so they match?
Or is that an entirely bad idea and I should mount it with the curved segments pointing up?

I attached a drawing of how I'd like to install the antenna (in red), the big rectangle on top is the battery, and smaller one the Vx transmitter.
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Old May 28, 2011, 01:54 PM
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Ah yes. I'm reading up on that.

Another question, I'm planning to mount the SPW Tx antenna upside down in the fuselage in a small bulge under the nose, which if I'm not mistaken would switch the polarization. So, should I make a left hand SPW and a right hand Cloverleaf so they match?
Or is that an entirely bad idea and I should mount it with the curved segments pointing up?

I attached a drawing of how I'd like to install the antenna (in red), the big rectangle on top is the battery, and smaller one the Vx transmitter.
It does NOT switch the polarization. right hand is always right hand even if it is upside down.
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Old May 28, 2011, 05:00 PM
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quick question:
what happens to the directivity of an cloverleaf or a skew planar wheel if i change the numbers of lobes i.e. 2,5,6,7,8 or more lobes?
and witch one should i use on the tx and witch one on the rx?
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Old May 29, 2011, 01:45 AM
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Argh!, I just realized I used the wrong dimensions for the wire length, I used a 105mm long wire to make an antenna for 5.945Ghz and according to the formula it should had been 101.1mm long.

Anyway, I did bend on element with that wire (let's call it a practice round) and found out that the ends of the wire didn't meet at the center, which had me puzzled until I looked back at the first post and noticed that the bend is actually not a circle.
I bent a circle with a diameter equal to the straight center section, and things didn't add up.

I made a drawing of how I bent the wire so you see how the arc segment I ended up with is 24.8mm instead of 26.4 (this is the wrong dimensions, haven't corrected them yet) So what I figured is that the curve is not a circle, what I haven't figured out is what shape it is supposed to be, an ellipse perhaps? I don't know how important is to get the correct curvature.

Anyway, back to bending wire....
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Old May 29, 2011, 03:52 AM
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It is hard to tell from the pictures but it looks like the arcs in most of the antenna do not start tangentially to a circle but rather start with a wider than 90 deg angle which may help to explain the discrepancy as this pushes the lobe outward some increasing the length of wire. Whether or not this *should* be the case or not I can't say.
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Old May 29, 2011, 04:03 AM
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It is hard to tell from the pictures but it looks like the arcs in most of the antenna do not start tangentially to a circle but rather start with a wider than 90 deg angle which may help to explain the discrepancy as this pushes the lobe outward some increasing the length of wire. Whether or not this *should* be the case or not I can't say.
I did a new set of drawings and this time I used the correct dimensions, on the finished shape I used the correct length for the curve (25.3mm), you can see how it compares with a perfect circle segment (in blue).
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Old May 29, 2011, 06:14 AM
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I did a new set of drawings and this time I used the correct dimensions, on the finished shape I used the correct length for the curve (25.3mm), you can see how it compares with a perfect circle segment (in blue).

Nice. adding this to my FPV folder for later use. Have you tested your antennas to see that they work well on channel 8

How did you go about working out the correct curve. My math has gone down hill over the years and ... I am not that smart anymore.
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Old May 29, 2011, 09:39 AM
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Nice. adding this to my FPV folder for later use. Have you tested your antennas to see that they work well on channel 8

How did you go about working out the correct curve. My math has gone down hill over the years and ... I am not that smart anymore.
I did the drawing in CorelDraw, I have an utility that tells me the length of a line, so I modified a circle arc sector until it had the precise length; the shape goes by the looks-about-right formula.
I haven't tested the antennas yet because I haven't even finished them, I just put the bent wires aside and I'll wait for a new video Tx to test them on, I don't want to tear apart my FPV plane to try them just yet.

I did check the math to calculate the length of an ellipse arc sector but it required more brain power that I can muster on a Sunday afternoon.
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Old May 29, 2011, 12:40 PM
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I did the drawing in CorelDraw, I have an utility that tells me the length of a line, so I modified a circle arc sector until it had the precise length; the shape goes by the looks-about-right formula.
I haven't tested the antennas yet because I haven't even finished them, I just put the bent wires aside and I'll wait for a new video Tx to test them on, I don't want to tear apart my FPV plane to try them just yet.

I did check the math to calculate the length of an ellipse arc sector but it required more brain power that I can muster on a Sunday afternoon.
My current antennas are made for the 5705 band. Since I am pushing the distance I can really feel that they are not near channel 8. I am thinking of making some at for that channel.
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Old May 29, 2011, 02:56 PM
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hey guys... tell me if these look ok.

So far, they seem to have worked a bit better than the dipoles. 5.8ghz 200w foxtech system.

Not sure if its good or not, but with the dipoles i was able to get about 300 feet. Now I can get 500 feet.

I attached a map to show my environment.

The camera/TX is mounted on a 1/10th scale car. So I am hoping once the TX is on a plane, I will get out a bit farther. Am I correct to think range will increase in the air?
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Old May 29, 2011, 02:57 PM
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FYI, the black stuff is heat shrink tube and liquid electrical tape.
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Old May 29, 2011, 03:37 PM
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hey guys... tell me if these look ok.

So far, they seem to have worked a bit better than the dipoles. 5.8ghz 200w foxtech system.

Not sure if its good or not, but with the dipoles i was able to get about 300 feet. Now I can get 500 feet.

I attached a map to show my environment.

The camera/TX is mounted on a 1/10th scale car. So I am hoping once the TX is on a plane, I will get out a bit farther. Am I correct to think range will increase in the air?
I use these on my 5.8ghz 200mw system and easily get 1km with a clear picture. I have flown them out to 3km (9000 feet). If you can build these you can also build yourself a 4 turn helical for extra range.
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Old May 29, 2011, 06:15 PM
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will hobby lobby craft gold plated memory wire work for these antennas? It is smaller diameter. Will that affect anything?
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Old May 29, 2011, 07:09 PM
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Realized that the SPW was backward. I made a new one.

I found it much easier to make 4 separate parts and solider each individually.


Ok, so 9000' in the air, but have you tried a range check on the ground at all?

I tried to see how far the new setup will go, but my damn Futaba 3PK on 2.4ghz ran out of range before my video. which for some reason was only 300'
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Old May 29, 2011, 07:13 PM
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will hobby lobby craft gold plated memory wire work for these antennas? It is smaller diameter. Will that affect anything?
I am using 18AWG solid copper wire. Not sure if that matters @ 5.8ghz, but it works really well for retaining the shape and not being fragile.

IBCrazy, can you comment on this for us?
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Old May 29, 2011, 08:56 PM
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I am using 18AWG solid copper wire. Not sure if that matters @ 5.8ghz, but it works really well for retaining the shape and not being fragile.

IBCrazy, can you comment on this for us?
That should be fine. Memory wire also works well for any frequency. I use Mig Welding wire because it is available everywhere.

-Alex
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Old May 30, 2011, 03:00 AM
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I've got ~300m (~980ft) on the ground so far with FrSky 2.4 ghz for control and 5.8ghz (200mw) for video. I'm looking for more open areas to go for a drive in as I run out of LOS quickly past that. Vid tx is 12" off the ground and the rc rx antennae are about the same. If the area is open and undulating I can sometimes drive a little out of LOS with video fuz as long as it isn't very far out of LOS but can't go around buildings at all really without the rc becoming very beepy (telemetry) and the video going to crap.
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Old May 30, 2011, 06:42 PM
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I answered my own question today. I strapped my camera onto my foamy and tossed her up in the air. I got the plane high enough that I was having a hard time keeping my climb rate steady. 2 flights, first time ever doing this. Absolutely awesome experience!!!

Up close, about 5-10 feet above ground I lose all video.

What would cause this?


Plane: 36" Profile Foamy
RC: 72mhz
vTX/RX: Foxtech 5.8ghz 200mw with CL/SWP
Camera: 690TVL Ultra WDR Pixim SEAWOLF 2.8mm

Whats up with my rainbow prop?!
Winds were 15-22mph, so the plane was more of a kite. Also, i need to figure out how to capture video without killing my laptop. pretty cool dive near the end of the video.

Foamy FPV Range Test (3 min 56 sec)
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Old May 30, 2011, 07:12 PM
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The "rainbow prop" is a side effect of the global shutter/cmos combo in the pixim cams. It is a better tradeoff than the "window blinds prop" from rolling shutter cmos cams.

Very nice camera! How heavy is it? Not sure what would cause the loss of video you had at the end. I've noticed I get weird colors/loss of video (black frame sort of thing) with really bad multipathing (driving the truck into an inside corner on a building at a moderate distance for ex). Perhaps there is enough ground clutter near where the plane was to cause issues?

The dive was great
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Old May 30, 2011, 07:41 PM
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no idea how much it weighs, but I am VERY happy with it so far.
690TVL-Ultra-WDR-Pixim-SEAWOLF 2.8mm

it cant be too heavy though, as my foamy still flys with it onboard.

Its quite funny how its attached too.
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Old May 30, 2011, 10:31 PM
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Well, first time I got to take my blu beam version of the SP out yesterday, then I was taking out my groundstation and the board I have everything on pulled away from its mount and landed on my truck seat, and unfortunately I had neglected to take the antenna off before loading it up, so it ended up getting scrunched.

Since I was trying it out with my new eagle eyes ground station with my bi-quad for diversity, I got it close to what I thought was original and put it on anyway. Then I was getting black screens when hardly any distance out in one direction, because I had also mistakenly set the EE unit to only use that antenna.

Now I am wondering if I can salvage it by getting it back to it's proper shape and form, so I'll be carefully reading the build instructions at the start of the thread.
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Old May 31, 2011, 01:52 AM
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Well, first time I got to take my blu beam version of the SP out yesterday, then I was taking out my groundstation and the board I have everything on pulled away from its mount and landed on my truck seat, and unfortunately I had neglected to take the antenna off before loading it up, so it ended up getting scrunched.

Since I was trying it out with my new eagle eyes ground station with my bi-quad for diversity, I got it close to what I thought was original and put it on anyway. Then I was getting black screens when hardly any distance out in one direction, because I had also mistakenly set the EE unit to only use that antenna.

Now I am wondering if I can salvage it by getting it back to it's proper shape and form, so I'll be carefully reading the build instructions at the start of the thread.
Should be no problem to fix. Start by bending the lower wires such that thea a) form a 90 degrees angle towards the connector, and also form a 90 degree angle among them seen from top. Then look at the plane the four lower wires form by looking a the antenna from its side and turn it up until you look at one lobe such that the straigh part you just bent before looks towards you. Now you can verify/assure that the lobe looks up in a 45 degree angle.

HTH

Markus
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Old May 31, 2011, 01:54 AM
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hello all...

i have a 5.8 system .. I made up only 1 clover antenna..
I think I got everything right.. well at least for first attempt..

But should I see an improvement ... .with only 1 ?

I only had 1 coax cable so .. I tested with it mounted on the Rx.. then on the Tx.. with stock at other end..

Test only indoors... image goes in and out every now and again..
I was going to make a second but I've have to destroy one of the coax antennas to get the part..

So I guess my main question was should there be a benefit with only 1..
so far dont see it..but maybe a second attempt may show better results..

Thanks all...
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Old May 31, 2011, 02:27 AM
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Originally Posted by flyhigh300 View Post
hello all...

i have a 5.8 system .. I made up only 1 clover antenna..
I think I got everything right.. well at least for first attempt..

But should I see an improvement ... .with only 1 ?

I only had 1 coax cable so .. I tested with it mounted on the Rx.. then on the Tx.. with stock at other end..

Test only indoors... image goes in and out every now and again..
I was going to make a second but I've have to destroy one of the coax antennas to get the part..

So I guess my main question was should there be a benefit with only 1..
so far dont see it..but maybe a second attempt may show better results..

Thanks all...
What you did is a skew planar wheel, not a clover leaf. The clover leaf is the same but with only three lobes. The antenna - from what I can see - looks nice.

Using one alone does not help. Make a cloverleaf (the one with three lobes) and use that one on the transmitter, the one you made on the reciver and you will experience a quantum leap in your video link quality.

Markus
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Old May 31, 2011, 10:46 AM
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What you did is a skew planar wheel, not a clover leaf. The clover leaf is the same but with only three lobes. The antenna - from what I can see - looks nice.

Using one alone does not help. Make a cloverleaf (the one with three lobes) and use that one on the transmitter, the one you made on the reciver and you will experience a quantum leap in your video link quality.

Markus
I second this. You need to build a 3 lobe for the TX and you will be amazed at your results.
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Old May 31, 2011, 11:32 AM
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Thanks.. all..

it worked.. I when ahead and used another of the antennas (stock) .. found another.. so I have 2 stock.. to test with..but not sure its even worth it.... I can see the improvement already...

having them where there is no physical barriers (Walls) .. you see clear difference over the stock...

Stock .. it would cut out several times in a minute.. lets just say... 5 or so per minute.. sometimes more sometimes less.. did not have the patience to quantify it..

but with the 4(skew planer ) on the Rx and 3(clover) on the Tx It goes minutes.. with out cutting out.. maybe 10min.. ect..

HUGE.. improvement .. now it does this when both are stationary..

ok now here is the part where I ask the not so intelligent questions..

If I hold the .. Tx in my hand wave it around .. role it .. point it back ect..
ie..perform a simulation as if it on airplane.. it does go out very frequently..

now.. this is indoors.. so I'm thinking .. the walls furniture may be causing.. signal to get "scrambled" my not so technical term.. ... or even me holding is is not good..

I guess the ultimate test will be outdoors..

Now I saw a few post on here about encasing the antenna in foam,
I plan to use a FunCub.. that has large cavity in the fuse..
I was thinking of mounting it in the center tail section..

I used very soft cooper (phone wire) to make these..so was thinking that may be a good idea.. as they are fragile.. or should I not waist time with that..

Well Thanks.. for this thread..

I have a few 900mhz setups that I never did anything with .. those will be next..


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I second this. You need to build a 3 lobe for the TX and you will be amazed at your results.
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Old May 31, 2011, 12:38 PM
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Thanks.. all..

it worked.. I when ahead and used another of the antennas (stock) .. found another.. so I have 2 stock.. to test with..but not sure its even worth it.... I can see the improvement already...

having them where there is no physical barriers (Walls) .. you see clear difference over the stock...

Stock .. it would cut out several times in a minute.. lets just say... 5 or so per minute.. sometimes more sometimes less.. did not have the patience to quantify it..

but with the 4(skew planer ) on the Rx and 3(clover) on the Tx It goes minutes.. with out cutting out.. maybe 10min.. ect..

HUGE.. improvement .. now it does this when both are stationary..

ok now here is the part where I ask the not so intelligent questions..

If I hold the .. Tx in my hand wave it around .. role it .. point it back ect..
ie..perform a simulation as if it on airplane.. it does go out very frequently..

now.. this is indoors.. so I'm thinking .. the walls furniture may be causing.. signal to get "scrambled" my not so technical term.. ... or even me holding is is not good..

I guess the ultimate test will be outdoors..

Now I saw a few post on here about encasing the antenna in foam,
I plan to use a FunCub.. that has large cavity in the fuse..
I was thinking of mounting it in the center tail section..

I used very soft cooper (phone wire) to make these..so was thinking that may be a good idea.. as they are fragile.. or should I not waist time with that..

Well Thanks.. for this thread..

I have a few 900mhz setups that I never did anything with .. those will be next..
You can place your antenna inside the fuselage, no problem. Just make sure that the line of seight is maintained during regular flight manuvers. In other words, that the line between the antennas is never blocked by the motor, battery or other conductive parts. Best spot to place the antenna is below the belly which should not be a problem if you have a landing gear. Out on the wings is also good, or on the top of the rudder.

Getting strange results while holding the tx in your arms is not a surprize. The body also operates like a ground and will have influence on the tuning of the antenna. Then, you of course also can block the signal with your body etc. etc.

HTH

Markus
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Old May 31, 2011, 01:29 PM
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Thanks Markus..

I took another look at my 3 (clover) antenna..

they where not at 45deg.. like in this video..

Cloverleaf antenna for FPV by IBCrazy (1 min 5 sec)


I bent them closer to 45.. and it's improved about 10 times.. now when I move it around.. it does not cut out as much ..
1failure to the 10 before..

cant wait to get this in the air.... will start the build tonight with some modification on that cub..

Anyone have a video link ..like the one above for the 4 (skew planer) ?
that made it so simple to understand the angles ..

Thanks.. again ..
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Old May 31, 2011, 02:37 PM
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I think it is the same, just has four instead of three.....90 degrees apart vs. 120 if I understand correctly....
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Old May 31, 2011, 03:50 PM
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are you talking about this fresh one?

The Skew-Planar Wheel (SPW) circular polarized omni antenna by IBCrazy (1 min 11 sec)





A+
JAy
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Old May 31, 2011, 07:31 PM
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Pair of completed skew planar antennas:



Right hand polarization. Side-fed with a short length of cable, for wing mounting.



Heavier gauge wire, for the receiver antenna.

Thanks for the awesome guide, Alex!

Jaybee!
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Old May 31, 2011, 09:34 PM
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Thanks..

That makes it easy to understand.. !

I did my first set.. really quick.. HUGE improvement..

will draw up some templates to get the angles as close to perfect..

Thanks,



Quote:
Originally Posted by terry74 View Post
are you talking about this fresh one?

http://www.youtube.com/watch?v=P-3hwU5ejbE




A+
JAy
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Old Jun 04, 2011, 03:25 PM
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Does anyone have a picture of their SPW jig? I am looking at making a few for my planes and I would love to see how people put their jigs together to speed up the process. I just finish making a cloverleaf jig that works nicely but I haven't thought up one for the spw.
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Old Jun 04, 2011, 03:43 PM
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It is same as CL, but 45 degree triangles at 90 crossover...
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Old Jun 04, 2011, 03:47 PM
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It is same as CL, but 45 degree triangles at 90 crossover...
yea I am guessing as much but I am building 5.8ghz and 2.4ghz antennas. So I have to keep that cross over point very small.
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Old Jun 06, 2011, 07:25 AM
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yea I am guessing as much but I am building 5.8ghz and 2.4ghz antennas. So I have to keep that cross over point very small.
Side feed or base feed? For side feed, I use magnets on a small metal plate. Drop the wires on them and it holds geometry.

For base-fed I use a split bullet inside a cylinder. I will post pictures if I can remember where I put my camera... Basically I have a cylinder with 4 magnets on the edge. The bullet has a small loe in the middle and is split in two. The cable comes through the center of the bullet, the cylinder hold the halves together. Dorp the lobes in and the magnets hold them in place for soldering. Add heat and solder and it does it perfectly every time. When soldered, push the bullet from the cylinder and it splits open to unlock the antenna.

-Alex
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Old Jun 06, 2011, 10:12 AM
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5.8g spw

0.5mm piano cord made

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Old Jun 06, 2011, 01:52 PM
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Originally Posted by IBCrazy View Post
Side feed or base feed? For side feed, I use magnets on a small metal plate. Drop the wires on them and it holds geometry.

For base-fed I use a split bullet inside a cylinder. I will post pictures if I can remember where I put my camera... Basically I have a cylinder with 4 magnets on the edge. The bullet has a small loe in the middle and is split in two. The cable comes through the center of the bullet, the cylinder hold the halves together. Dorp the lobes in and the magnets hold them in place for soldering. Add heat and solder and it does it perfectly every time. When soldered, push the bullet from the cylinder and it splits open to unlock the antenna.

-Alex
that sounds like a great plan. Love to see a picture still as I am more visual that ... reading learner

but magnets sound like a great idea!!
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Old Jun 06, 2011, 01:53 PM
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0.5mm piano cord made

My hat off to you. they look bloody good!
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Old Jun 06, 2011, 11:53 PM
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this post was originally about my bent-then-straightened blu-beam cpw antenna, moved over to VAS customer support thread..
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Old Jun 21, 2011, 03:20 AM
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Many thanks
Can't wait to try out my SP and CL combination
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Old Jun 22, 2011, 09:40 PM
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Taking a break

Many of you have noticed I haven't been around as much. It's because I have been burned here on RCG. I will continue to be active on FPVLAB where it appears there is a much more mature crowd.

You can find me and post questions here as I monitor this regularly: http://fpvlab.com/forums/forumdispla...Aerial-Systems

That is also where I plan to launch my new antenna designs.

Take care all of you,

-Alex
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Old Jun 25, 2011, 03:40 AM
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Sad to see this FPV world split due to a single person...
No, Alex, it's not you
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Old Jun 26, 2011, 11:13 AM
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It's not just one. It's about a dozen people on here. You (and almost everyone posting in this thread) is not one of them.

-Alex
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Old Jul 15, 2011, 05:13 AM
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This is how it looks my:.

Now need to solder coax.
Plan to fit that on my receiver it's made for 1140mHz and got clover on plane.
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Old Aug 02, 2011, 03:15 AM
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I am going to build one for my own, but I do not get much. Does "The Skew-Planar Wheel circular polarized omni antenna" connect 2 poles of the antenna together?
Because I saw that most of atenna does not do this.
Thanks,
Duy
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Old Aug 02, 2011, 04:20 PM
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Yes, the various types of S-P/cloverleaf/etc are a 'dead short' as in a DC circuit, BUT in an RF circuit, the Tx 'sees' around a 50 ohm load.

Not easy to explain or understand as DC circuits are different to RF circuits.

Just believe it and go ahead and make one as per the various topics...

Nigel.
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Old Aug 02, 2011, 10:55 PM
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Hi Nigel,

I just double checked with my TX and RX. Without antenna, the TX (Immersion 600mw), two poles are not connected. RX (Airwave) two poles are connected, and it seems to be that there is a capacitor or inductor between them, because I saw that, the led went bright firstly and then came lower and kept the light.
Or does my RX died? this is new and I only can catch the video very nearly about 10-20m.
So that, I am trying to build an antenna for this.(5.8G).
Thanks,
Duy
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Old Aug 03, 2011, 02:31 AM
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I don't know the Immersion Tx or Rx so can't help with the LED situation but you should always have an antenna connected to any Tx before applying power as you may well damage the Tx if you do not have a correct antenna connected. You will not hurt the Rx without an antenna.

With 600mW, you should easily get some hundreds of metres with good signal (providing there are no line of sight obstructions). You will often get some horrible distortions due to multipath signals at the Rx, which is where the CP antennas help a huge amount by significantly reducing multipath signals.

Have you built 2 CP antennas?
If so, are they both the same polarity (physically 'twisted' the same direction)?
Have you got both the Tx and the Rx set to the same channel?

Maybe you should consult Sander regarding your Immersion hardware.

Nigel.
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Old Aug 03, 2011, 03:39 AM
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Thank a lot for the information.
I am building CP antennas.
I do not mean I powered the TX and RX and asked for the led there.
I just tested 2 poles of the female-RSA port of TX and RX if it connected or not.
I powered a led via the female-RSA port of TX and RX. With TX the led was not on and the RX the led went light and then it lowered and kept the light.
So, I saw that the TX, 2 poles are not connected together and the RX, 2 poles are connected. This is different. I asked is it normally or failure with something?
Is it failed with RX (I thought)?
But I still see the video with this system but the range is very nearly.

Thanks Nigel again,
Duy
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Old Aug 03, 2011, 10:58 AM
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At least Airwave receivers have power on the antenna jack. You have to disable the power feed somehow in order to use "short circuit" antennas like SPW or CL. If you just throw SPW or CL in it shorts out the power coming out from the antenna jack and (presumably) shuts off the receiver.

For one particular Airwave module there's some kind of tutorial on how to disable the power from the antenna jack: http://www.electronicarc.com/catalog...roducts_id=532 The picture is not clear but you have to cut one lead on the circuit board.
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Old Aug 04, 2011, 06:44 AM
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Duy - There are many different types of antennas. Some are "closed loop" and others are open type. Examples of open types would be patch antennas and dipoles. Some examples of closed loop types would be BiQuads, skew planar wheels and the folded dipole (often used as a Yagi feed).

Once a piece of wire gets to 1/4 wavelength long, it begins to resonate and the resistance changes dramatically. At microwave frequencies, 1/4 wave length is only a few cm.

-Alex
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