Few questions about FPV

[tincho2019]

friends
I want to experiment with FPV any transmitter and long range receiver that you can recommend me?

FPV transmitter, receiver and lenses etc.???

Thanks in advance.
MAV

 

[BashingBrian]

I too would be interested in this...

I have mentioned it once before in another post somewhere on here...??

 

[Ari33]

I do fpv on quadcopters and occasionally on my typhon.. so I know a fair bit about it.

Define long range.. and what about budget?

1.2ghz has superior range and penetration but interferes with 2.4 ghz as a harmonic frequency and so requires the use of notch filters etc and it gets a bit more complicated and is more expensive... so I'll assume you will be using 5.8ghz. You have a vastly larger purchase choice range with 5.8ghz and its a fair bit cheaper too.

I'd suggest going for simple box type goggles to start off with. Some have an inbuilt diversity receiver (Vtr) which just means that you can have two types of antenna. One for 360deg coverage (ie; stock whip or Cloverleaf) and perhaps a patch or 3 turn spiral antenna for a higher gain but focused beam cone. The Vtr will switch to the antenna which has the higher signal strength. If you start getting picture interference you can point your head/goggles/antenna towards the car and the higher gain directional antenna clicking in on the Vtr due to its higher swr will improve the image quality... IF.... the image breakup is due to range rather than going out of line of sight. Ie; over a hill or behind a large dense object such as a building.

If you wear glasses you should probably look at the mirrored 800 x 400 resolution FXT Viper or perhaps a higher resolution 7" screen box goggle such as the Skyzone SJ-V01 which is a cheaper direct copy of the Headplay HD SE... which is a copy of the Eyebox 7" goggles... which I use.
I also have a 1080p resolution 5" screen Eachine goggle 2 with around 55 deg FOV but my Eyebox's 75 deg FOV is much more preferable to me.
The larger in FOV you go, the higher in quality and in TV lines you will need with yhe cam.. to make them shine. The SJ-V01 offers the best value for money IMO and being a direct Headplay clone this is the kind of performance you should expect from them when used with a decent cam...

Fatshark type goggles typically have a 35-45 deg FOV so the picture may appear sharper but its only because you have a far smaller FOV and you are looking at a small screen from a relative distance.... akin to looking at a 32" tv across the other side of a room. Some people prefer that while others prefer the more immersion of a far larger, vision envoloping screen that is closer to your eyes natural FOV. Thankfully for my wallets sake, I fall into the latter camp.... YMMV.

If money is no object...
DJI have just released a full HD digital system which is over a grand (gbp) Image quality is superb at close range but due to how the tech works, the frame rate drops with distance and/or signal strength.. which is a real shame.
The best Fatshark type goggle is probably the new Orqa. They have really nice OLED panels (just like Fatsharks top of the range HDO's) but with a higher resolution and slighly larger FOV.

For vtx/cam..
If thinking basic and budget... and not planning on going further 50-60m away from you in line of sight...and also not too fussed about having the very best picture quality, then the Runcam tx200u AIO (all in one) combined cam & vtx might be good enough.

At ground level on cars you are hugely affected by the huge load of obstacles on ground topography compared to in the air.
Higher output power always helps with obstacle penetration (trees etc) so I would choose a vtx in the 500mw to 1w power range.

TBS make the best VTX's available currently in terms of size weight and features but you will pay as much as 3 times the price for the privelage... and most of the features other than.. the power output being throttled down by generated heat feature, they are of no great deal on a car.

AKK make some decent higher power 5.8ghz vtx's. They don't have the same power output throttling to excessive heat generation feature as the TBS unify pro etc.
Bear in mind that vtx's on a car wont receive half as good airflow going over them campared to most quads/planes and so most likely wont be able to handle full power without overheating... so I'd probably run a 1000mW (1W) vtx at around 600mW, at least to start with... and monitor the temps accordingly.... Oh and never power up a vtx without the antenna on... as it will damage it pretty quickly.


Use a seperate power source for the vtx/cam Vdc in as the vdc feed from the car ESC's BEC will most likely be very noisy and introduce a lot of voltage spike interference to the picture.
A seperate BEC... or better still, a seperate 1s lipo in the 500 -1000mAh range will give you the cleanest vdc line to power your vtx/cam.
Ideally you want to be able to power the cam and the vtx from a single seperate 1s Lipo so as to avoid potential voltage spike buzz interference from the vtx's own BEC, most of them are ok but some are a bit noisy.
Some vtx's and cams have a really wide voltage input range and could use anything from 1s - 6s lipo voltage. Some vtx's also have their own 5v to 9v reg to power the cam so really pay attention to this area so as not to over/under volt your vtx and/or cam.

Cameras- The Runcam Eagle 2 and Runcam micro eagle are my fav cams. They have ultra WDR (ultra wide dynamic range) so you can still see very good picture details in a very wide brightness/darkness range bright sun and shade. They use a larger diameter and better quality lens than their closest competitors and for me the RC Eagles have most beautiful picture once you turn down the sharpness a bit to get rid of the 'shimmer'.
Latency is around 25ms which is a wee bit higher than the other competitors but unless you are racing in fpv it is perfectly fine.
They are a tad more expensive than most other cams... so there are other options out there if you find them a bit pricey.

For a car, the wider 16:9 format is defo the better choice so I'd choose a cam and goggle which use the 16:9 format natively rather than introduce black bars or stretch the image if you mismatch them.
Camera lens size choice is a personal thing. I use 2.1, 2.5 and 2.8.. with the latter giving a widest FOV (field of view) but also causing some image distortions. I'd try a 2.5 first and see if you want to go lower or higher in FOV. You can buy different focal length cam lens's seperately if desired and just swap them over.

Antennas- I use the Aomway 4 leaf cloverleafs. Perform better than most other cloverleafs in lab measurements but are cheaper and tougher.

I use an Armatan mrp fpv pod which I just zip tie on to the rear wing of the typhon or bolt to the top of my quads.
For the typhon I don't mount the vtx and antenna in the pod though, I ziptie it horizontally on the wing with the antenna pounting out the back so that it doesn't get hit during rolls and crashes.

https://www.armattanquads.com/armattan-mrp-micro-pod/


Here is a great source of info for all things fpv related - https://oscarliang.com/choose-video-transmitter-fpv-mini-quad/

There is also a guy called Traxxalu on you tube who does loads of surface based fpv ranging from basic external mount to cockpit view inc a rev tacho. and also with pan & tilt headtracking etc.... on everything from airboats to 6x6 rock crawlers, and rescue missions using other fpv vehicles.. really impressive videos.

He also has some good 'how to' videos if you go into his playlist.

 

[tincho2019]

Hello Ari33

Thank you very much for all your explanation and the truth that helped me to realize that I am in diapers on this. But eager to learn.
I want to achieve a distance of about 1 km, that's enough for me.
I liked the Skyzone SJ-V01 and FXT VIPER Version 2.0 FPV Goggles Video Glasses with 5.8 GHz lenses
You can tell me which transmitter, receiver and antennas to buy following your recommendations. I don't want it for competition, it's just for personal projects and fun.
If you are kind enough to indicate the links to buy.
Thank you so much for everything!

 

[jondilly1974]

Here’s a good video that explains Fresnel Zones and their impact on your range. I deal with F zones in my day to day work. I install point to point wireless networks and have to be aware of things like this when designing systems. 5.8ghz isn’t going to penetrate thru objects as well as 1.2ghz, but the F zones will be smaller. Depending on the environment your running on, you may choose a different frequency.

 

[arrmadillo]

Really impressive stuff there guys! WOW

 

[Ari33]

Here’s a good video that explains Fresnel Zones and their impact on your range. I deal with F zones in my day to day work. I install point to point wireless networks and have to be aware of things like this when designing systems. 5.8ghz isn’t going to penetrate thru objects as well as 1.2ghz, but the F zones will be smaller. Depending on the environment your running on, you may choose a different frequency.

Yes, a lot of people doing surface fpv use 1.3ghz which is really out of my area of knowledge.

To me 1km sounds quite far for surface fpv on 5.8ghz but as you say... the topography and objects in the environment are the main factor on what would work best.
Sit on top of a 20m high platform and you will less likely go over hills to block the direct signal and you probably could get 1km in some favourable circumstances.

I suspect the OP may well get bored with surface fpv quicker than he thinks so I'm a bit hesitant to tell him to spend a small fortune on the fpv gear that I cant promise would get him to 1km.

I've tried fpv a few times on my typhon and while it was a welcome change of perspective and worked quite well within 50-60m at 600mW. There is no way I'd invest that amount of money on surface fpv alone if I didnt have planes and quads.


I reccomend the OP joins RCGroups and asks for for surface specific fpv advice on what frequency to use in their fpv section there.
Happy to help with what I can help with but not going to give BS advice outwith my remit.

 

[Lazy Bushman]

Presumable microwave @jondilly1974 ?

 

[jondilly1974]

Presumable microwave @jondilly1974 ?

No, not that far of backhaul. I install surveillance camera systems and wireless links are needed when pulling fiber is cost-prohibitive. Usually very short distances and low bandwidth, so 5.8ghz is used mostly. 2.4ghz is very congested here in the USA. 900mhz is used when LOS isn’t available. Anything above 5.8ghz is beyond the scope of my work. I’m usually using Ubiquiti Networks products. They are very low cost.

 

[Lazy Bushman]

I used to do networking, microwave etc back in the day...not now nor the last 10 year for that matter. Had to factor in Fresnel zone across water to various islands but i’ve Forgotten more than I knew now