Modifying oem antennas & locations , Good or bad or stupid ?

[Lofuel]

I'm installing these mikrotik cards and my mind just goes and goes how to make things "better" let's call it.. as a computer nerd I have tons of old parts and computers around.. so a qwk look and I find a cable that connects to the wifi cards and on the other end takes ur normal side antennas (like on controller) ..

So what if we took the oem leg ones out with a little antenna on them , covered by tape and surrounded by the plastic leg , and move them towards the rear with 2 antennas like the oem ones in controller .. or if your feeling bold lol the alfa's .. looks the the back underside where the "link" jets out would house 2 of these coax connectors and just screw the antennas on ..

Here's a few ref pics .. I only found one of these cables .. might order another and find a shell to try it..


Or is this just really stupid idea and I'd crash and burn?! I obviously have no background in radio frequencies or any sort so to someone that does this may make u laugh

 

[dmyhill]

Directionals like Alfas might be a bad idea.

The question is whether any gain is to be found in the alternative antenna you have proposed. Do you know the specs of the antenna in the leg?

 

[andrew.baker.142]

Two things:
You don't want the antennas any closer than necessary. That is why they are so far apart in the stock configuration.
Replacing the stock antennas with " rubber ducky" ones isn't going to get you anything. You do not want to go with directional antennas either (will limit your flight envelope). The stock antenna configuration is actually pretty good.
If you really wanted to put different antennas on the bird, get some circularly polarized ones (but you should also update the ones in the controller too). I plan on installing the SMA connectors you show in one of my Solos with CP antennas. Don't expect a huge improvement in range but should have a more robust link.

 

[Pedals2Paddles]

^ What he said. The whiskers in the legs are 0db gain, which radiates and receives equally in all directions. This is ideal because the aircraft can be at any angle facing any direction at any time. If you put antennas with gain (like the controller's rubber duck antennas), the signal is flattened out horizontally. This is problematic on a platform that moves and changes angles. Circular polarized antennas on both ends are the best option for UAS since not only do they radiate and receive equally in all directions, but there is no cross polarization loss as the angle changes like there is with vertically polarized antennas.

 

[andrew.baker.142]

Another bonus with CP antennas is they will provide a 3dB loss to linearly polarized signals, so if you upgrade all 4 of your antennas to CP, then all the WiFi signals (which are all linearly polarized) in the area you are flying naturally get reduced by 3dB due to the physics. A 3dB drop in the noise floor can be very beneficial in some areas!

 

[Frank Foster]

So anybody have an opinion on which CP antennas to use? How about the new "Far View"? I bought 4 of their kits, and assembled them, but have not really tried them out yet.
Pagoda Antenna Maarten Beart better than clover leaf

 

[Pedals2Paddles]

Those 5.8ghz. not for use on 2.ghz wifi.

 

[Frank Foster]

Ah right, not thinking.....

 

[andrew.baker.142]

I got a pair of these last week. Hope to install them this weekend.
VAS - 2.4 GHz Cloverleaf Whip Antenna RHCP - Right Angle [CL-2400-90] - $19.95 : Ready Made RC LLC, The Leader in All Things FPV, RC, and Beyond

 

[Pedals2Paddles]

Those are perfect! Those are actually what I've been keeping in the back of my mind to put on the aircraft. Just trying to find something directional and matching to put on the controller too.

 

[Jubalr]

Those are perfect! Those are actually what I've been keeping in the back of my mind to put on the aircraft. Just trying to find something directional and matching to put on the controller too.

I used those on a build a while back for video. They worked great. Had the matching ones on the Tx as well. Would like to see a Solo test with those too.

 

[Pedals2Paddles]

Since I have enough spare parts, I will probably put those on my experimental solo and controller first. It will be rocking AC3.5 and matching CP antennas!

 

[David Boulanger]

I got a pair of these last week. Hope to install them this weekend.
VAS - 2.4 GHz Cloverleaf Whip Antenna RHCP - Right Angle [CL-2400-90] - $19.95 : Ready Made RC LLC, The Leader in All Things FPV, RC, and Beyond

Do you need to use a SMA to RP SMA adapter?

 

[andrew.baker.142]

I'm installing a set on the aircraft now. Should be able to test it this weekend.
The ufl to SMA cables I installed have SMA connectors, so no adaptors needed on the aircraft side. I will need to use an adaptor to connect my (new) VAS Crosshairs to the controller.

 

[Pedals2Paddles]

That's exactly the pigtails I was going to use too. Where did you get them from? Decent quality? I was looking at those crosshair antennas yesterday as well. The description says they're 5" by 5". But then some pictures and videos make them look massive. What are you ideas for mounting the cross hairs to the controller?

The FPVLR and REXUAV long range antennas are CP. But they come with one LHCP and one RHCP. They do that one the assumption you're talking to the solo's stock linear antennas. I've asked both if they make one custom that has both RHCP antennas, that way they would match with two RHCP antennas on the solo. If they can do that, it would cost about the same as buying two crosshairs, and not require customization.

 

[Pedals2Paddles]

Actually, I was doing some more reading and it appears MIMO would best with one of each on each end. So the solo and controller should each have an LHCP and a RHCP antenna. That's what the FPVLR and REXUAX kits have. So the controller end can be done without any custom stuff with one of those kits. Then just put on of each antennas on the Solo. Should perform REALLY well.

 

[andrew.baker.142]

I got the pigtails from readymaderc (and the VAS antennas also).
I had actually asked Alex (I beCrazy) who owns Video Aerial Systems that exact question. He believes all the antennas should all be the same direction of rotation for best results, but one of each direction would probably work as well. You can find the discussion over on the FPVLabs forum under "Sponsors Gate". I'm just too challenged to link across using Tapatalk on my iPhone to provide the link.
If you think about it, with linear antennas they are all the same polarization (vertical) and it obviously works fine.

 

[David Boulanger]

Actually, I was doing some more reading and it appears MIMO would best with one of each on each end. So the solo and controller should each have an LHCP and a RHCP antenna. That's what the FPVLR and REXUAX kits have. So the controller end can be done without any custom stuff with one of those kits. Then just put on of each antennas on the Solo. Should perform REALLY well.

It's my belief, could be wrong, that using CP antennas with linear antennas is defeating the main purpose of CP antennas. CP antennas, on both the TX and RX, will see a lot less multi pathing and not hear junk RF as strong if flying in a high noise floor environment. Although, I agree that CP antennas on the Solo only is an improvement over the stock whiskers. My guess is RHCP clover leafs on Solo + RCHP crosshairs on the controller, with stock Wi-Fi cards, will provide amazing range providing the crosshairs are pointed at the Solo. Clover leafs on the transmitter instead of crosshairs will be very good and more forgiving with transmitter orientation.

 

[andrew.baker.142]

The Crosshairs are in fact 5 or so inches square. They also have some MDF as a durable mount so they are probably 3" deep. I'll get some pics uploaded tonight.
I'm not sure exactly how I want to mount them, but probably be something 3D printed. I also have my antenna tracker up and running so I want something I could use on the tracker or the controller.
The Crosshairs have a 1/4x20 mount so I could just easily bolt them to some sheet stock. Still thinking about this.

 

[andrew.baker.142]

It's my belief, could be wrong, that using CP antennas with linear antennas is defeating the main purpose of CP antennas. CP antennas, on both the TX and RX, will see a lot less multi pathing and not hear junk RF as strong if flying in a high noise floor environment. Although, I agree that CP antennas on the Solo only is an improvement over the stock whiskers. My guess is RHCP clover leafs on Solo + RCHP crosshairs on the controller, with stock Wi-Fi cards, will provide amazing range providing the crosshairs are pointed at the Solo. Clover leafs on the transmitter instead of crosshairs will be very good and more forgiving with transmitter orientation.

Totally agree with you. There is a 3dB loss mixing linear and circular polarization. Not sure why they did it. Probably cause it looks cool and can be compact. All CP is the way to go!