2.4GHz for video and RC - not a good idea?

[markvanhaze]

Im new to FPV and have been reading a lot of posts on various sites where pretty much everybody says to fly your RC on 35MHz or similar if you have the video on 2.4GHz.
I have a 2.4GHz RC setup and am now looking into buying the FPV setup. I have a friend at our local flying club and he has both running on 2.4GHz. According to him its not an issue and he has no interferences.
Is that hot air or what's the trick to it?

[g.collins]

Hi markvanhaze
You don't want both on 2.4, that's for sure, if you are flying 2.4 RC, you are better of getting 5.8 Video.
:) G

[Malcr001]

The logical answer you think it would work seeing as 2.4ghz rc tx's like spektrum use frequency hopping spread spektrum technology but the reality is it doesn't work when you using video on 2.4ghz too and its a little dangerous too. Also if you ask this in rcgroups people will tell you not to use 2.4ghz for rc link at all. For fpv you have 35mhz and 459mhz UHF for rc which are better options. Ideally as recommended by TBS your rc link should have longer range than your video so when you experience the limit of your video range you are still able to turn back without any problems.

[FPVSteve]

Yep, 35MHz and 2.4GHz here. I'd never run 2.4GHz on both, if he wants 2.4GHz for control then I suggest 5.8GHz video.

[markvanhaze]

Thanks for the replies. Then another question - if I use 2.4 for RC, can I use 1.2GHz for the video or are there interferences?

[Miles]

Thanks for the replies. Then another question - if I use 2.4 for RC, can I use 1.2GHz for the video or are there interferences?

1.2 is illegal in the uk ;) It is also a harmonic of 2.4 so you rtill get interference.

[Malcr001]

Thanks for the replies. Then another question - if I use 2.4 for RC, can I use 1.2GHz for the video or are there interferences?

You can BUT 1.2ghz (1240mhz - 1360mhz if I recall correctly) is for HAM users and it isnt legal for "airbourne use" but this doesnt seem to get in the way for some fpv'ers. If you use a 1.2ghz vtx it is recommended you use a low pass filter to reduce harmonics. A list of low pass filters here:

These were the first guys to sell them:
http://www.dpcav.com/xcart/product.php?productid=16438&cat=0&page=1

There are other people selling them cheaper:
http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_45_52&products_id=484&zenid=ruqnpcl2euss5km7mhi66nl441

http://www.rangevideo.com/index.php?main_page=product_info&products_id=261

http://www.foxtechfpv.com/9001300mhz-band-pass-filter-p-325.html

[Miles]

So essentially, 1.2 is useless for FPV, it is only legal if you get an exception from Ofcom, which is very hard.
If you are caught using 1.2, their is a large fine, somewhere £1000+. Can't remember how much exactly. Its the same with incorrect radio freqs. Using 40mhz on planes etc is a £2000 fine.
Just use 5.8 for video or get UHF.

[FPVSteve]

Where do you get those fines from?

I was reading the OFCOM and CAA court prosecution lists a while back, and I saw nothing like that. Not saying you're wrong, just interested to see some actual facts if they exist.

[Malcr001]

Anyone know if its ok to use 1280mhz for video (with callsign and HAM license) for rc car fpv? My dad has a full HAM license and doesnt see a problem but he doesnt exactly check on the rules everyday.

[Miles]

Where do you get those fines from?

I was reading the OFCOM and CAA court prosecution lists a while back, and I saw nothing like that. Not saying you're wrong, just interested to see some actual facts if they exist.

Mate of mine works with Quinetic to make UAV's, he has the licenses that you need to waiver the regs. Also details the fines etc if you don't have the license

@Malcr
If you have the licenses, it is legal, but you still need one of a legal power limit (No idea what that is though)

[Malcr001]

@Malcr
If you have the licenses, it is legal, but you still need one of a legal power limit (No idea what that is though)

I dont think power output is a problem, last time I read most HAM frequencies are allowed to run a tx on a number of watts. Cant check right now though the ofcom spektrum info website seems to be down at the moment.

[markvanhaze]

Again, thanks for all the info. So if i want to keep my 2.4ghz RC system the best and legal option is to use 5.8ghz for video. Are there any differences between 2.4 and 5.8 video systems in terms of performance?

[Malcr001]

Again, thanks for all the info. So if i want to keep my 2.4ghz RC system the best and legal option is to use 5.8ghz for video. Are there any differences between 2.4 and 5.8 video systems in terms of performance?

5.8ghz is a LOS frequency meaning if you have anything and I mean ANYTHING in between your vtx and rx you wont get a solid signal. Thats one of the disadvantages with 5.8ghz. However if you want the best video quality 5.8ghz is the best seeing it has the largest bandwidth. Personally I dont see a great difference in video quality between 1280mhz and 5.8ghz but some people swear by a big difference. It depends whether if your flying in a urban area or not but if your not I would personally go with 2.4ghz video and 35mhz rc (change to 459mhz rc when you have the money) the equipment out there is fairly advanced in comparison to 5.8ghz which means you can get longer range through more sensitive rx antenna's. However that being said 5.8ghz is catching up year by year but no matter how technology changes it will still be a loss frequency which is something to bear in mind. Either way 2.4ghz and 5.8ghz are used for lots of commercial products so your vulnerable to something causing interferance. 5.8ghz will be less populated but as I said its catching up and has its own disadvantages to bear in mind.

[g.collins]

Again, thanks for all the info. So if i want to keep my 2.4ghz RC system the best and legal option is to use 5.8ghz for video. Are there any differences between 2.4 and 5.8 video systems in terms of performance?

to cut a long story Short, Yes, if you wont to keep your RC stuff.
;) G