Long Range FPV Antennas for ELRS & Crossfire + Diversity RX
Vložit
- čas přidán 28. 07. 2024
- Anyone who's serious about flying long range FPV should consider using a diversity receiver with a vertically polarized RX antenna. For both Express LRS & Crossfire this second antenna is most often mounted vertically at the back of the drone, beside the video antenna. It will help to improve the quality of the communication link between transmitter and receiver as well as minimize the chances of a failsafe (total loss of control). We're going to make a 915/868mhz dipole antenna from scratch.
My Long Range FPV frame designs:
-Falcon RPM 7.5" Cinematic / Long Range @ AddictiveRC - bit.ly/Falcon_RPM_AddictiveRC
-Falcon RPM 7.5" Cinematic / Long Range @ CNCDrones - bit.ly/FalconRPM
- RAD Li-ion 7" Long Range - bit.ly/3MFoCdg
- RAD Scout 7" Xtra Long Range - bit.ly/3kyvPDy
- AOS Falcon 7 Cinematic Long Range - bit.ly/3jUiLUI
Parts list and affiliate links for 6s long range build - (great reliability and balance between power and efficiency)
T-Motor F7 Pro flight controller - bit.ly/3xtW1mE
T-Motor F55 Pro II ESC (4in1) - bit.ly/3uITNOF
Motors for 7" props: T Motor F90 2806.5 1300kv - bit.ly/3M4fjDg
Motors for 7.5" props: T-Motor Velox 3008 1500kv - bit.ly/3QJ8Gcf
Camera Butter ND Filters - bit.ly/3WZmSQR
7" props for RAD Scout - Gemfan 7035 (tri-blade) - bit.ly/3vdSzKu
7" props for RAD Li-ion - Gemfan 7037 (tri-blade) - bit.ly/3rvCz5f
7" props for Falcon 7 - Gemfan 7040 (tri-blades) - bit.ly/3YaxFrZ
7.5" props for Falcon RPM Gemfan 7535 (tri-blades) - bit.ly/3vdSzKu
VTX antenna TrueRC Singularity - bit.ly/3xvXFEg
VTX - bit.ly/3JHWW5l
Receiver - bit.ly/3xuMGv8
FPV camera (analog) - bit.ly/3JL88OT
GPS - bit.ly/3uJjRci
Receiver antenna - bit.ly/3jG7o2L
Video Chapters:
00:00 - Introduction / using a diversity antenna
02:05 - Required materials
03:45 - Cutting SMA extension to length
05:45 - Stripping the outer shielding
08:30 - Adding heat shrink & antenna stiffness
13:30 - Counter element (made from shielding)
15:45 - More heat shrink
17:12 - Installing counter element
20:45 - Important note about antenna construction
21:25 - Make sure the elements are properly sized
22:22 - Conclusion
Consider supporting the channel on Patreon:
www.patreon.com/user?u=48131636
Check out my frame design page @ CNCDrones: bit.ly/3vvRrD7
Use this link for the purchase of anything from GetFPV with no extra cost to you, but it helps the channel out: bit.ly/3roKZui
Thanks for the sharing Sir, best long range content
Thanks a bunch for the lesson, dude! 😃
Stay safe there with your family! 🖖😊
Thanks! 😃
Nice work as usual thanks for sharing your build method.
No problem 👍
Sweet! Thanks for making this type of content man, very good information.
Unbelievable and epic content at your channel!
Congratulations and thanks for sharing!
Thank you very much!
Just discovered the topic go onto youtube and the Goat has sth coming up many thanks for all of these wonderfull and informative videos
nice video!! Purchased two bardpole antennas with SMA connectors (one for an Falcon7; in-work build and the other for the AOS V3 build); this vid will be fun to make my own long range antennas!! Thanks!!!!
Hey thats great. I was just about to embark on making one of these. Good timing.
Just got ya!!! Looking forward to your content!!! Thanks for taking the time to share your knowledge.
Thanks and welcome
Thank you great video
Do a video of your video workflow? Always looks nice!!!
I just build my 7" Rekon and a little nervous on how far. Running Vista. Thanks for the videos
No I don't but thanks for a video idea!
A vector network analyzer, like the nanoVNA, would be a good idea to tune the antenna and be sure it's well designed, it's not that expensive (amazon...).
Ya I looked it up $80 for one that'll do 915mhz, or about $180 for one that'll work on both 915mhz 5.8ghz video antennas. I may well invest in a VNA.
👍👍👍Unbelievable and epic content at your channel! Congratulations and thanks for sharing!💯💯💯 FalconRad, I have an idea for very long range , please can you test it out for me to see if it works ? what you have to do is this, go and take a ride in a hot air balloon at 400 metres high then lunch the drone , that way you should have a better line of sight in all directions from the balloon , would this work , please FalconRad make an educated guess. thanks
Yes for sure it would work. As long as you have line of sight to the drone, you'll have signal. You might lose video if you were to fly underneath the balloon though.
Ok Thanks for your info ,@@FalconRadFPV
excellent tutorial sir! since you suggested to have this dipole vertically polarized at the rear and have another T antenna horizontally polarized at the front, what would be the optimum transmitter T antenna polarization? horizontal or vertical?
I keep my TX antenna vertical, some people I fly with will put it on a 45 degree angle off of vertical. Both ways seem to work well.
@@FalconRadFPV you really got me thinking with the 45deg! i suppose this middle ground should work for the two receiver antennas perpendicular to each other. oh well nothing beats actual use case where science somewhat flies out of the window. i will certainly give this a try. much appreciated sir!🫡
Great video.I have accidentally ordered TrueRc SMA Bardpole 868Mhz the 280mm version 😅, can i make it shorter , will it afect the tune ? 😁
it would be tough to cut open, shorten and reconnect properly. Although I'm sure it could be done, as far as affecting the tune I don't think so, "I think" the length is more about helping if the impedance is off.
@@FalconRadFPV Thank you 😁
Interesting, what's the difference between this super of antenna and just taking a regular T antenna and bending it so the ground lead is parallel with the feed line and the active element sticks up? So it's the same straight line, If you know what I mean
It's pretty much the same thing. This is intended for long range drones where simply bending an immortal t on an angle won't give the performance required for getting really good range, like 10km+. Mounting a bent over immortal t will be hard to get high up in the air above your battery and GoPro. This DIY antenna lets you mount it easily and also gets the antenna in a position that will have the best chance of getting signal from the TX. But ya, I've flown way out using only immortal t antennas, sure.
Hey how can you tell which end is the active element of a T antenna??
@@gregdavidd both, it's a dipole
Is it better to mount a true diversity setup both vertically? One in the front one out back. I stay level mostly. I only yaw to turn around. My transmitter antenna is also vertical.
If you stay mostly vertical you'll probably be ok without diversity and a single vertical antenna in the back. With the quad tilted forward as it flies a vertical antenna in the back will always have good line of sight over top of the quad. It just needs to be long enough to get over the battery a little bit. I use antennas around 120mm for my video and about 180 to 200 mm for my vertical crossfire antenna in the back. It would be of the most benefit to have a second antenna at least on a different angle, if you were to mount one in the front I'd suggest having it on some amount of angle, 25 to 45 degrees.
So I got a true rc bardpole antenna on my long range quad and I’m noticing worse signal than the immortal T. Could it be my orientation?
For a vertical bardpole you'll want you TX antenna to be vertical as well. For an immortal T strapped to an arm (horizontally mounted) you want the TX antenna oriented the same way.
Why not just using copper tube, I bought it from TBS, they are using copper tube.
Copper tube is an interesting idea! Probably great for a TX antenna. As for using it on a drone, I would wonder how durable it is? This antenna can be bent in half and still be useable.
Not much info on google i will try here😂 does shortening a 5cm pigtail to 3cm has any affect on range or something else?
I don't think it makes too much difference on the pigtail length, but I believe that it does help to be the right length if the antenna's impendence if not quite right. If I remember right the best size for 5.8ghz extensions is multiples of 17.72mm. For instance a lot of antennas have a coax cable length of about 88 - 89mm. So you would want to change the 5cm pigtail for one that's more like 3.5cm. The length does not include the pin at the end.
Very nice. have you considered selling them?
No I haven't, maybe if I get a VNA and can be sure of the reception quality then I could start selling them.
I got a question. I've been doing long range in the west tx desert. How high should I fly if I'm 5k away? I'm using dual VAS crosshair extreme on rapidfire hdo2. I don't understand the beam pattern.
As long as you fly out in front of those crosshair antenna's you should be fine. For higher altitude flights you may want them to be about 45 degrees up. Don't over think it to much just go out and fly. Have RTH setup and working in case you need it. I have a pepper box antenna that's all I use with an old immersion receiver works great. Cross hair antenna's have a pretty wide and vertical beam width. Don't get behind any tree's buildings or mountains your signal will go out.
The height you need to fly at will depend on what's on the ground in between you and the drone. In the desert I think you should be able to go 5km out with only a few hundred meters of altitude. The beam pattern on that is probably just a cone shape, so center it on the direction you are flying in and possibly point it up just a little when you get farther away and up to a few hundred meters. (of course only if it's safe to do so, I try to never go more than 120 meters above the ground below the drone.)