Taking FPV Desicions

[colorex]

Taking FPV Desicions

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OK, I recently read this awesome article about an FPV setup on the FliteTest site, and also chatting with nonamerc over here.

So anyway, I was filling up too many comments on the article, so I decided to continue the discussion here.

So what I'm looking for is the cheapest solution available, while still maintaining a reasonable quality.

Defined requirements are:

- Not 900 MHz - cellphone network interference
- Not 2.4 GHz - radio uplink interference
- More or equal to 200mW Tx power
- Range 1Km with homemade cloverleaf and skewplanar antennas
- No goggles
- HobbyKing stuff preferred
- Minimal complexity
- Aiming at portability

I was considering 1.2/1.3 gear because of the reduced range of 5.8, but I'm eventually tempted to use 5.8 as it seems to have less harmonic interference from 2.4 (so it requires less or no filters).

This is the current watchlist. It might take a year until I get started with it, but I can still learn a lot.

Tx/Rx

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=15295&aff=524347

Camera

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=13434&aff=524347

I like this camera mount (eve if I would only use pan with the rudder channel, maybe a switch to control tilt)

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=12875&aff=524347

Any cheap 7" screen off of eBay.

Any metallic case to make it as awesome as this:



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This is the conversation so far:

I've only had the opportunity to test this setup on my quadcopter, as I'm currently building my plane right now. That being said, I've flown FPV on my quad within LOS but beyond my capability to distinguish it with my naked eye. How far that was? Hard to tell, but I would guess somewhere around 400-500 meters. I'm sure it could do a lot farther considering other's have achieved much greater distances on the same hardware.

Sounds like enough range for me... I love your clean setup, I'm totally making something similar when I get my gear! Is there a reason you prefer 5.8 over other frequencies? I've heard that 5.8 gives you less range at the same power output...

I'm glad you like it. I chose 5.8GHz for two reasons. First, I remember seeing one of IBCrazy's videos a while ago where he explained that 5.8GHz has the ability to transmit higher quality video as opposed to the lower frequencies. Second, the antenna selection in 5.8GHz is a lot smaller and more compact than any of the other frequencies. In my case, the cloverleaf and skew planar fit very easily into a small case because they were compact. If I had gone with 1.3GHz or some other frequency, transportation and portability would have become a problem. Now, it is true that due to the high frequency of 5.8GHz you won't be able to pass the signal through many hard objects and a clear LOS is required most of the time. However, with some good circular polarized antennas you can get a descent signal through many hard objects. As a test, I was able to get signal reception through 6 walls in my house, two of which were exterior walls. This was pretty decent for my use, so I think I'll stick with it.
Also, just a side note...5.8GHz with a skew planar and a cloverleaf can give up to 5km in range. Other frequencies like 900MHz can give much greater range, but I don't ever think I'll be flying more than 5km

With the 200mW? I think that's with higher power transmitters...

Yep, that range can be achieved with this setup. Here's a video where someone reached 7km using a 200mw 5.8GHz setup. They had a cloverleaf on the transmitter and a 6-turn helical on the receiver. http://youtu.be/thwJGbdCa0M

Well, that's understandable with a patch antenna... I'd personally prefer omni reception. How do you think this would work out? http://www.hobbyking.com/hobbyking/store/__15295__5_8g_200mw_FPV_Wireless_AV_Tx_Rx_Set.html http://www.hobbyking.com/hobbyking/store/__13434__1_3_inch_SONY_CCD_Video_Camera_NTSC_.html http://www.hobbyking.com/hobbyking/store/__21283__2_1mm_F_2_0_Turnigy_Micro_FPV_Camera_Lense.html http://www.ebay.com/itm/7-TFT-LCD-C...ltDomain_0&hash=item256ecc72d8#ht_2903wt_1396

those all look like good items for an FPV setup. The only thing I might suggest is keeping your eyes open for a better deal on a 7" screen. There are lots of other vendors on eBay that can ship a 7" screen to you for around $25.

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[colorex]

I have a question to start with... that receiver is stated at a 5v operating voltage... is that what you use? I thought it was 12v...

 

[ukarmy04]

I have a question to start with... that receiver is stated at a 5v operating voltage... is that what you use? I thought it was 12v...

The receiver can support anywhere from 7v to 12v (2s or 3s LiPo). There is a small voltage regulator inside that takes the input voltage and reduces it to something the receiver can use. Now, when you use a 3s LiPo the voltage regulator has to do a lot more work to bring the 12V down to a usable voltage, therefore the receiver gets pretty hot. If you use a 2s LiPo, the receiver will still get warm, but it won't get as hot as a 3s would make it. Lots of people have used both 3s and 2s and I haven't run across any issues with either of those except for the heat. In my setup, I initially had the receiver connected to the 12v line coming from the battery, but because I live in AZ, the whole thing would get burning hot under regular use. So in order to compensate for this, I rewired the receiver to tap into a 9v line coming from the LCD screen. This is somewhere between a 2s and 3s LiPo's voltage and it brought down the amount of heat the receiver was outputting. So to sum up, the receiver will work off either a 2s or 3s, with a 3s it produces more heat.

 

[earthsciteach]

I'll toss in a question: Can two fpv systems of the same frequency operate at the same time, if on different channels? Are there different channels?

 

[colorex]

Oh, Ok. Maybe I could find a screen that works off 5 volts, and use a UBEC to regulate the voltage from a 3s. Do you think there are 5v screens available? Otherwise I could just run the screen off 12v and the Rx off the UBEC - as here in Ecuador it's really really really hot everyday.

On that note, it's hard to find cheap screens with shipping to Ecuador. This is the cheapest I found. Suggestions are welcome.
7" TFT LCD Color Car Rearview Headrest Monitor DVD VCR | eBay

I showed my friend (flies planes as well but no FPV, lives 8 hours away) your setup and he likes it a lot! But I think he would get something with more range.

Welcome to the forum!

 

[UndCon]

On my small FPV pod I have

5.8ghz 200mW
5V Turnigy UBEC
HK E-OSD

coupled with a tiny $16 camera

Using cloverleaf /Skew

 

[colorex]

On my small FPV pod I have

5.8ghz 200mW
5V Turnigy UBEC
HK E-OSD

coupled with a tiny $16 camera

Using cloverleaf /Skew

Range? Is the $16 camera from HobbyKing?

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I plan on using a separate battery for FPV gear - Between 500 and 1000 mAh - just to get a clean voltage supply for the Tx.

 

[ukarmy04]

Oh, Ok. Maybe I could find a screen that works off 5 volts, and use a UBEC to regulate the voltage from a 3s. Do you think there are 5v screens available? Otherwise I could just run the screen off 12v and the Rx off the UBEC - as here in Ecuador it's really really really hot everyday.

On that note, it's hard to find cheap screens with shipping to Ecuador. This is the cheapest I found. Suggestions are welcome.
7" TFT LCD Color Car Rearview Headrest Monitor DVD VCR | eBay

I showed my friend (flies planes as well but no FPV, lives 8 hours away) your setup and he likes it a lot! But I think he would get something with more range.

Welcome to the forum!

Thanks for the welcome. That's a good idea - using a UBEC. I'm not sure I've seen any 5v screens - as they're usually 12v or higher to power the LED backlight. Your best bet is to probably power the receiver off the UBEC, like you said. That way you can swap it out if anything ever fails and it ensures low temperature for the receiver.

Also, I don't think I've seen many sellers that ship to Ecuador at a similar price to my screen. That DVD screen you linked is probably the best option unless you can find something cheaper/bigger.

I'll toss in a question: Can two fpv systems of the same frequency operate at the same time, if on different channels? Are there different channels?

There are 8 different channels on the RC305 receiver, and you can switch between them to obtain the best signal between your transmitter and receiver. However, all 8 channels are pretty close in frequency and it might be a little risky to be flying around interfering systems. One thing you could do is use circular polarized antennas and make sure you and your buddy have opposite polarizations (i.e. you have right hand circular polarized and your friend has left hand circular polarized). This way you won't ever get his signal appearing on your screen and vice versa. It is important to keep in mind that although this ensures the signals won't get crossed, you're both still using channels somewhere in the 5.8GHz band - so there might be interference or shortened range. I can't speak any absolutes on this because I haven't flown with someone who was also on 5.8GHz, but it might be doable.

 

[UndCon]

My camera is not from HK in that setup - it is Chinese factory
The range is so far unknown - I don't fly that far away with my Quad but I think it is more than enough with those antennas

 

[colorex]

Thanks for all your answers! Just as a quick update, here's my progress on my tricopter.

 

[PaulT]

Andre, have you checked out my build blog ? It is almost identical to bmsweb's setup
I just got out to 2 kms the other day, which is at or near the limits of the spektrum radio I would suspect.
Everything is HK except for the 25 dollar tft monitor.

 

[colorex]

Andre, have you checked out my build blog ? It is almost identical to bmsweb's setup
I just got out to 2 kms the other day, which is at or near the limits of the spektrum radio I would suspect.
Everything is HK except for the 25 dollar tft monitor.

Oh, I didn't realize that - You use exactly what I have on my list I'll check it out!

 

[Rcjim11]

Hey Colo, on the yaw mech, did you use carbon fibre or steel as the pivot between the steering mounts?

Cheers

 

[Nonamerc]

Hi Colorex,

I don't think that you should order FPV from hobbyking since fpv systems are fragile. If you break your fpv system wich you bought from hobbyking you should not expect any help. So I think you should buy from sites like foxtechfpv.com and readymaderc.com

Also the difference between the two video qualities of 1.2 GHz and 5.8 GHz is there but most people will only see it on a big tv screen. Since you are going to buy a 7inch tft monitor the difference wont be really big. Maybe only noticable when you are looking for it.
Also if you really do care about the picture quality I suggest that you dont buy the camera from hobbyking which you had in your list because the picture quality is pretty bad. It's cheap because it's not a really good camera. So I suggest that you buy this camera:
http://www.foxtechfpv.com/fh18c-520tvl-12v-mini-camera-pal-p-256.html

Also the 5.8 GHz band is getting more crowded then 1.2 GHz. Also the filters for 1.2 GHz are optional if you want to do medium range. You can always order the filters if you want to go further then 1km.

Also 1Km with 5.8 GHz is possible but not near citys because you will get allot of interference. We fly with 5.8 GHz near our village and we can get about 400m max. Also you should know that 5.8 GHz is really much affected by humidty and rain. We have flown our 5.8 GHz system to 1Km (We flown that in farmlands far away from citys) but we had to tunr arround because of the clouds. I dont know how humid ecuador is but I think that you maybe should consider 1.2 GHz.

1.2 GHz is not hard to setup, you can buy cables from readymaderc which makes it a plug and play system.

Also dont buy 900 MHz systems because they are really outdated because almost no one uses them.


Greetings Arman,

If you have anymore questions just ask them!

 

[colorex]

Hey Colo, on the yaw mech, did you use carbon fibre or steel as the pivot between the steering mounts?

Cheers

I used a 4mm metal rod, which probably isn't steel, but I got it from one of those play sets with metal pieces with holes in them and lots of bolts and nuts. The rod used to be a wheel axle.

 

[colorex]

I don't think that you should order FPV from hobbyking since fpv systems are fragile. If you break your fpv system wich you bought from hobbyking you should not expect any help. So I think you should buy from sites like foxtechfpv.com and readymaderc.com

I realize anything I buy from HobbyKing might arrive damaged and be hard to replace. But I've heard good things about the gear from several people. I'll consider your thoughts - being a more expensive investment, but having tech support readily available.

 

[t.korb]

Very nice and interesting.. thinking about trying this as a first attempt in FPV. Question though- can a OSD or GPS be incorporated in this kinda setup easily..and if so what would I need besides the OSD and GPS sensor..? Sorry maybe seem like a newbie question..but I am a newbie in FPV. Any consideration or recommendations would help thanks

 

[Nonamerc]

Very nice and interesting.. thinking about trying this as a first attempt in FPV. Question though- can a OSD or GPS be incorporated in this kinda setup easily..and if so what would I need besides the OSD and GPS sensor..? Sorry maybe seem like a newbie question..but I am a newbie in FPV. Any consideration or recommendations would help thanks

Hi t.korb,

Welcome to the forum!

You can buy osd's like ezosd:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17745

It's really easy to install.
You will have gps (not return to home) mah consumed battery voltage distance from home and more.

If you want to get a return to home. (if your signal goes out the plane will return to home)

I recomend that you this one:
http://www.foxtechfpv.com/cyclops-nova-osdmah-bug-fixed-p-402.html
This one is a bit harder to setup but there are videos on how to do that.

I hope I helped you out.

 

[colorex]

Would you guys recommend a separate battery for the FPV system? I think it's the best way of avoiding noise from the ESC. How many mA do a camera and vTx combo draw?

 

[PaulT]

I use a separate 1300 Mah to run the tx and camera. Not sure what they draw for current but I have run two back to back 2200's for a total flying time of about 1.5 hours and still have 9.4v left in the smaller battery.
Also the simple osd I use is only showing voltage on my main battery. When I advance onto a more complicated and better quality system I will monitor both batteries.
My simple HK system was to see if I wanted to advance further without expending bigger $ for the experiment.
My biggest expense was the antennaes which were well worth the investment.
Something to keep in mind is what I teach people in driving EMS and fire trucks.
Never overdrive your lights!
There is not much point in having a video system that can go 5 kms with radios that can't control your plane.