[gixerfien]

Ok gurus...again I could not find this info on here so figure I'd start up a discussion on it.

I'm started to get a grasp of this stuff but I'd like double check what I think is right...or not?!?...

So I'm understanding that the circular polarized antennas are suppose to give you better coverage for short range. Also I know you need to match them so either both vtx and vrx must both have either LHCP or RHCP antennas.

Ok so after that is sorted...what is the deal with these diversity Vrx...because you only get one antenna option for the Vtx but 2 now for the Vrx.

So tell me if I understand this correctly or do I have it all wrong and to get diversity you need to use 2 Vtx(and if I'm right then please vote on your best choice)...K so If I were to use RHCP antennas (which I understand are the better choice because they are more common than LHCP ones)...

I would do something like this here on both the Vtx and Vrx?...

https://www.rotorquest.com/index.php...duct_id=108873

https://www.rotorquest.com/index.php...duct_id=105933

https://www.rotorquest.com/index.php...duct_id=108459

And then for the 2nd antenna on the Vrx...I would have to keep it RHCP still...but would use a different style like this?...

https://www.rotorquest.com/index.php...duct_id=108661

https://www.rotorquest.com/index.php...duct_id=106428

https://www.rotorquest.com/index.php...duct_id=102423

I don't have to go as far as using a long range antennas like these to get the use of diversity do I?

https://www.rotorquest.com/index.php...duct_id=105937

https://www.rotorquest.com/index.php...duct_id=106053

[gixerfien]

really...34 people to look at this and no one knows

Must be a ton of others who are curious to find out too then!!

[cravenjw]

It's a huge topic and lots to learn.
Have you used google? Super easy to find lots of tutorials and videos about these topics!

http://www.dronetrest.com/t/the-comp...our-drone/1473

https://oscarliang.com/linear-circul...d-antenna-fpv/

The main difference between linear and circular is that circular reduce multipathing effects
What is multi pathing?

This is simple vid that covers the basics of circular antenna rejection on multipath interference.
https://youtu.be/AuGBgTC6ph4

You use all right or all left. Never mix them.
Even on diversity RX use same handedness.

Yes most people start with right. They are more common. If you fly alone it makes no difference. If you fly in races with 6-8 people, alternating left and right on adjacent channels improves things a bit. But you can't have two quads on the same channel using different hands! The handedness effect is no where that strong! If you did mix antennas, ie left on quad and right on goggle, you will still get reasonable video at close range, it will be crapper at longer ranges, and no where as good as same handedness!

[cravenjw]

Diversity RXs give you a way to combine the good aspects of two different antennas.

Sticking to quads and close range FPV, this almost always means an omni directional and a directional. The omni give you good close coverage of equal strength in all directions, it allows you to "behind you", but it isn't great for longer ranges. To cover the long ranges you point a second direction antenna where you think it will do best.

Let's say your quad racing on a football field. your sitting on the sideline at the 30 yard line. Most of the track is in your half. But there is a speed run out and around the far goal post. onmi is going to cover your half, while your directional that you pointed at the far goal, is going to cover you on the far run.

There's a bunch of different directional styles! Each style has a vertical and horizontal coverage that have pros and cons. Having a couple different styles of directional antennas allows you to cover different tracks or fields that you fly.

I race, but I also fly a bit of RC club FPV. At one field there's some fly trees and bushes that are a great to weave thru. But there a brutal dead spot, folliage and a hydro tower. With a omni only, it's always a blackout! But point a simple patch at that spot on the diversity RX and you can fly right with only slight interference.

If you doing aerobatics, there's is a null directly over your omni, and flying close but high is a weak spot for you omni. In that case a patch pointed out in front and but tilted upwards give you high altitude diversity where your omni is weak.

[gixerfien]

Originally Posted by cravenjw

It's a huge topic and lots to learn.
Have you used google? Super easy to find lots of tutorials and videos about these topics!

http://www.dronetrest.com/t/the-comp...our-drone/1473

https://oscarliang.com/linear-circul...d-antenna-fpv/

The main difference between linear and circular is that circular reduce multipathing effects
What is multi pathing?

This is simple vid that covers the basics of circular antenna rejection on multipath interference.
https://youtu.be/AuGBgTC6ph4

You use all right or all left. Never mix them.
Even on diversity RX use same handedness.

Yes most people start with right. They are more common. If you fly alone it makes no difference. If you fly in races with 6-8 people, alternating left and right on adjacent channels improves things a bit. But you can't have two quads on the same channel using different hands! The handedness effect is no where that strong! If you did mix antennas, ie left on quad and right on goggle, you will still get reasonable video at close range, it will be crapper at longer ranges, and no where as good as same handedness!

Yes I did use google, I'm not one of those guys now!! lol

I read both those links you provided prior to starting this and was left still a bit fuzzy on what do to for the 2nd antenna

the youtube video you provided tho does look rather interesting with all the antenna hes got on the table there(gonna go watch it now)

an I never even mentioned anything bout linear antennas

After speaking to a couple more people this evening, I'm being told to use this for the 2nd antenna cuz using a clover and dome styled one together isn't doing much extra

https://www.rotorquest.com/index.php...duct_id=106428

[cravenjw]

You havent said what your flying.

Open antenna like the vas BLue whip are great on planes. Low drag.
For a race quad, the tbs triumph is great antenna that is tough and small.

[cravenjw]

You haven't described where you plan to fly.
One place more than others
always different.

[Max]

Cory.
Diversity is simply being able to choose which signal is better and piping that into your main screen.

In my early days, I made a manual diversity using a toggle switch. 2 VRX's, one fed a smaller 4" screens and the other went to my man screen. I used a toggle switch to pipe whatever signal looked clearer onto my 14" screen. if the 14" screen got fuzzy but the 4" screen looked good, I would flip the toggle. The smaller screen sat on top of my main screen.Worked like a charm

I've since then gone to eagltree Diversity. Its self switching based on whichever signal is stroonger. You can diversity 2 or more VRX's. Its not hard to diversity 4 VRX's if you had enough diversity boxes (you would need 3).

As for CP antennas, like John says, they are best for reducing multipathing interference. Whatever hand you are using CP, you are stuck with. With diversity, you then need 2 antenna's of the same bias but have different gain. In my case, I would use a standard cloverleaf antenna (omnidirectional) on one diversity input, and a high gain directional helical on the other .

Also keep in mind the directional antenna has a very narrow beam. So you will need some method of pointing it at the model. I prefer a manual system (servo driven). Others use an automatic system driven by their diversity/models GPS data.

[gixerfien]

I don't have anything yet but will be pulling the trigger very soon, I plan on doing mostly fpv racing at the 2 current clubs I belong to(whitby and kawartha) and will probably travel to an event or other club field/course sometimes with it as well, ans also probably some exploring around the house with a micro fpv quad...Don't really have any interested in aerial filming or anything of that nature.

Ya I think thats the point I thought I better double check Max, because in your sticky for fpv for dummies you make a comment about dual Vtx with a diversity Vrx and it threw me off!! lol

That's probably why I was suggested a patch antenna over the longer range helical since I was talking to 2 racing guys.

I always wondered how well the long range ones work consistently since they're a narrow signal path like you mention...makes me think you'd get a fuzzy situation and have to start bending your head and moving in different directions till you get the clear picture again(like playing with the rabbit ears back in the day haha)??

[Max]

Originally Posted by gixerfien

I always wondered how well the long range ones work consistently since they're a narrow signal path like you mention...makes me think you'd get a fuzzy situation and have to start bending your head and moving in different directions till you get the clear picture again(like playing with the rabbit ears back in the day haha)??

Or mount everything onto a hard-hat and just turn your head... LOL
Dont laugh, I've first seen this done by VRFlyer, one of the foremost FPV pioneers years ago and it worked amazing. You just gotta mount each VRX on either side of the helmet to get the diversity working