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Old Oct 19, 2011, 08:09 AM
um.. yeah, I can make that fly
Carlos230023's Avatar
United Kingdom, Milton Keynes
Joined Jun 2007
3,731 Posts
So more this sorta thing

eBay item No.390357424203

CJ
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Old Oct 19, 2011, 11:56 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,446 Posts
^That'll do it. You need to get a set of adapters for it. Buy Amphenol, not the cheap adapters. Ask Sander how bad cheap adapters with stuff like that. He was so mad he chopped it open on a band saw.

-Alex
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Old Oct 19, 2011, 02:33 PM
um.. yeah, I can make that fly
Carlos230023's Avatar
United Kingdom, Milton Keynes
Joined Jun 2007
3,731 Posts
Nice one! I'll get all that ordered up. Lol I've cut a few things that annoyed me in half but not usually with anything as aggressive as a band saw :P.

CJ
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Old Oct 22, 2011, 09:38 AM
Expat
Japan
Joined Apr 2010
3,024 Posts
Quote:
Originally Posted by IBCrazy View Post
Yes, but the #18 wire is not. It is too soft. You need a plated steel wire.

-Alex
Thanks. I just finished going to every hardware store in town, and none even knew what Welder's wire was, and none had steel plated wire. They had varying gauges of copper, steel, galvanized and stainless steel wires. I guess these are not acceptable? Sorry, I could easily find what you've listed, if I was back in an English speaking country. Stuff like this is a lot harder here though.
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Old Oct 22, 2011, 09:55 AM
New Beeeeee
RUBNorris's Avatar
United States, CA, Sacramento
Joined Apr 2011
1,073 Posts
Alex,
I just picked one up from your new store! Can't wait to use it!!!
(and I could not get my 5.8 DIY to work lol)
I'll help u so u can continue to help us all.

Ruben
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Old Oct 22, 2011, 12:10 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
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Quote:
Originally Posted by TheNiceGuy View Post
Thanks. I just finished going to every hardware store in town, and none even knew what Welder's wire was, and none had steel plated wire. They had varying gauges of copper, steel, galvanized and stainless steel wires. I guess these are not acceptable? Sorry, I could easily find what you've listed, if I was back in an English speaking country. Stuff like this is a lot harder here though.
A galvanized steel wire would work. So would brass plated steel or copper plated steel. If you want, I can send you some of the wire I use. It's dirt cheap here. Just pay to ship it over there.

-Alex
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Old Oct 22, 2011, 12:37 PM
Pilot
Ai77's Avatar
Deutschland, RP, Winningen
Joined Oct 2010
32 Posts
Radome Material

Quote:
Originally Posted by markus123456 View Post
Regarding the PingPong ball, I'm not so sure it helps that much. Maybe against a very small push but they are not so robust anyways.Markus
Hi.

The ping-pong ball is robust enough for transportation and the usual impacts with landing, grass, bush, sand, ... if the plane survives a crash, the ball will survive too.

I do not recommend using it as a langing gear....
but some minor dents will cause no technical problem, as there is enough distance to the antenna wire.

Some important things about radomes in 5.8 GHz: using the "wrong" material could cause frequency shift due to varying dielectric constant (plastics may be 3 to 27), causing bad SWR and worse performance. There is also dissipation (transmission loss, like opacity in optics). The celluliod material has proven to be quite "translucent" to 5.8GHz and the dielectric constant is a pretty predictable and constant 4 for all real celluloid.

The best material in dielectricity is styrofoam, but transmission loss is quite high, due to diffused H2O molecules from environment air, making a used piece quite unpredictable and varying under different operating conditions.

cheers,

Ai
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Old Oct 23, 2011, 08:33 AM
Expat
Japan
Joined Apr 2010
3,024 Posts
Quote:
Originally Posted by IBCrazy View Post
A galvanized steel wire would work. So would brass plated steel or copper plated steel. If you want, I can send you some of the wire I use. It's dirt cheap here. Just pay to ship it over there.

-Alex
Thanks very much for the offer Alex. I'll send you a PM.
Regarding the wire, I take it the treatments to steel are to avoid corrosion? Also, such galvanized or coated wire should be of the same standard gauge as the you mention at the outset?
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Old Oct 23, 2011, 11:02 AM
Alicante, Espaņa
Joined Jun 2010
379 Posts
I went today to 30 km with my Phoenix Evolution, with a Cloverleaf in the plane, an helical 15,5 turn in ground, and the Dragon Link LRS.

http://www.rcgroups.com/forums/showt...4#post19672913

Circular polarization IS ABOUT LONG RANGE also.
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Old Oct 23, 2011, 05:04 PM
Nek
DIY O.G.
Nek's Avatar
French Polynesia, Windward Islands, Faaa
Joined Nov 2002
313 Posts
Hey Alex,

Thanks a lot for those designs!!! I used David's tutorial from rcexplorer.se to make mine.

Sadly I only had access to RG174 cable but my soldering skills are decent enough to not have heated up the cable too much, but I fear my cable length is maybe too long and causes some considerable loss??

Here is the VTx CL antenna and some close ups:







And this is the VRx SPW antenna:





I thought it would be better to have the VRx antenna some inches away from the actual VRx in the googles, bad idea to have such a long cable? Same goes for the VTx antenna.

I guess I could just desolder and redo them shorter if it really is a potential issue.

I could only try some flights in a park with lots of tress and large bushes. I could fly around low behind those and maintain decent signal. Range was nothing crazy something like 100-200m.

I will try doing a proper range check with LOS and see how good those antennas work compared to my stock rubber duckys and see if mine are straight enough...

Thanks for any insight on my home made setup!!
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Old Oct 23, 2011, 11:38 PM
Registered User
atckirk's Avatar
Poway, CA USA
Joined May 2001
197 Posts
Is this antenna RHCP or LHCP? HELP

I have had this antenna for a while and want to make some cloverleafs and I figure I might as well make them match. The flytron website only says circular polarized not left or right. Thanks. Kirk.

http://www.flytron.com/osd-headtrack...h-antenna.html
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Old Oct 24, 2011, 01:08 AM
Suspended Account
United States, FL, Maitland
Joined Apr 2011
2,109 Posts
Quote:
Originally Posted by atckirk View Post
I have had this antenna for a while and want to make some cloverleafs and I figure I might as well make them match. The flytron website only says circular polarized not left or right. Thanks. Kirk.

http://www.flytron.com/osd-headtrack...h-antenna.html
I'd say right hand but let IBCrazy respond because his answer will be correct. Do the right hand rule starting at the base. The corkscrew goes left(counter clockwise) so that's why I say right hand.
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Old Oct 24, 2011, 07:28 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,446 Posts
Quote:
Originally Posted by Nek View Post
Hey Alex,

Thanks a lot for those designs!!! I used David's tutorial from rcexplorer.se to make mine.

Sadly I only had access to RG174 cable but my soldering skills are decent enough to not have heated up the cable too much, but I fear my cable length is maybe too long and causes some considerable loss??

Here is the VTx CL antenna and some close ups:







And this is the VRx SPW antenna:





I thought it would be better to have the VRx antenna some inches away from the actual VRx in the googles, bad idea to have such a long cable? Same goes for the VTx antenna.

I guess I could just desolder and redo them shorter if it really is a potential issue.

I could only try some flights in a park with lots of tress and large bushes. I could fly around low behind those and maintain decent signal. Range was nothing crazy something like 100-200m.

I will try doing a proper range check with LOS and see how good those antennas work compared to my stock rubber duckys and see if mine are straight enough...

Thanks for any insight on my home made setup!!
2 issues with that antenna:

1. Your take off angles seem a bit too flat. You want the wires to leave the coaxial cable at a 40-45 degree angle.

2. RG174 is VERY lossy. You are probably only getting 40% signal strength out with that long run. Go with RG316. That's what I use.

I never really ready RCExplorer's how to, but I would assume it is accurate. I have seen his CL builds and they appear dimensionally accurate.

-Alex
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Old Oct 24, 2011, 07:32 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,446 Posts
Quote:
Originally Posted by atckirk View Post
I have had this antenna for a while and want to make some cloverleafs and I figure I might as well make them match. The flytron website only says circular polarized not left or right. Thanks. Kirk.

http://www.flytron.com/osd-headtrack...h-antenna.html
That looks more like an elliptically polarized antenna rather than a circular one. CP isn't done by making round shapes. It is done by vector phase coordination.

I have abandoned the CP patch idea. Patches are sub-optimal antennas IMHO. L-COM and ReadyMadeRC sell 8db CP patches that work ok. I was going to sell CP patches at one point, but the performance did not meet my requirements.

-Alex
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Old Oct 24, 2011, 08:08 AM
Build Fly Crash Repeat
crezzee's Avatar
Worcester UK
Joined Nov 2004
788 Posts
Quote:
Originally Posted by Nek View Post
Hey Alex,

Thanks a lot for those designs!!! I used David's tutorial from rcexplorer.se to make mine.

Sadly I only had access to RG174 cable but my soldering skills are decent enough to not have heated up the cable too much, but I fear my cable length is maybe too long and causes some considerable loss??


I thought it would be better to have the VRx antenna some inches away from the actual VRx in the googles, bad idea to have such a long cable? Same goes for the VTx antenna.

I guess I could just desolder and redo them shorter if it really is a potential issue.

I could only try some flights in a park with lots of tress and large bushes. I could fly around low behind those and maintain decent signal. Range was nothing crazy something like 100-200m.

I will try doing a proper range check with LOS and see how good those antennas work compared to my stock rubber duckys and see if mine are straight enough...

Thanks for any insight on my home made setup!!
Dude 200m is not very good at all for a 600mW vtx, some guys on here have been getting 3000m + with 200mw 5.8Ghz vtx and Omni antennas.

Problems:

It is quite easy to make 5.8Ghz CL and SPW antennas that apear to work but tiny adjustments with these small antennas will send them way off frequency especially that blob of hot glue in the centre, that can shift the resonant frequency up a gig or 2. You really need to tune these antennas to get them to perform well.

Your lobe angles on the CL and SPW look a bit flat (might be the photos playing tricks though).

Whilst it works, RG174 is not really designed for 5.8ghz so if you must use it then make it as short as possible. Those long lengths will attenuate the signal quite alot. Also the length of cable can have an effect on the resonant frequency. Even small changes like right angle SMA's as opposed to straight SMA connectors can influence the tuning.


Placing the VTX out on one of the booms of your tri could also help keep signals isolated to reduce rf noise floor.


I like the undercarriage on your tricopter, they look very similar to the floats out of my young sons floating swimsuit, i wonder if he will miss a couple
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