Questions about frequency overlap with 2.4ghz and 433mhz

[Noah410]

Hi. I'm planning out a build for a sky hero spy, and I'm planning on using two immersionrc 700mw 2.4ghz vtxs (us version) for the pilot and camera operator down link. I'm also going to be using two ezuhf jr module Txs and two 8ch diversity Rxs. SO my question is; Will the two VTXs have enough space between the channels 2396, 2410, 2430MHz? And would running one of them with RHCP antennas and the other with LHCP antennas be of any help? I'm also wondering if the ezuhf system will suffer from having two recievers and transmitters in close proximity to each other despite them being able to frequency hop.

Thanks,

Noah

 

[SJBrit]

Couple of things: yes, running RHCP on one VTx and LHCP on the other will help and it's free so definitely do that. You shouldn't have a problem with the EzUHF Rx but you are definitely going to want to put an inline low pass filter on the EzUHF Tx on the ground to protect your 2.4 GHz Rx's from harmonics. Something like this one: http://hobbywireless.com/filters-an...-pass-filter-for-433mhz-sma-sku530-p-712.html.

 

[kloner]

i run a similar system on a few aircraft and there is zero problems..... except i'm on lawmate 2.4 which is all the same tech. the main problem with 2.4 vtx is a lot of the bands are used a lot and it takes licensing with fcc to use anything but ch1 and 2....... I'd have to go look it all up to what frequency that is in lawmate..... none of this stuff is fcc part 15 so it's technically all illegal

 

[Noah410]

Thank you SJbrit and Kloner for helping me out. I will make sure to get a lowpass filter for the LRS system. I'm also planning on getting a HAM radio license before I go out and fly (even though I doubt that I'd get caught). I'd prefer to stay "legal" and buy the immersionrc VTx with the limited 3 frequency setup, though I'd be willing to get in unlocked international version if the restricted channels will help me avoid interference from things like WiFi.

Thanks

 

[kloner]

it helps a lot, the hobbyking version of lawmate vtx have all 8 ch unlocked and are the industry standard in that frequency range.....

 

[Noah410]

it helps a lot, the hobbyking version of lawmate vtx have all 8 ch unlocked and are the industry standard in that frequency range.....

Alright, I'll get a lawmate vtx then. I've only used 5.8ghz and 900mhz, so what mw rating do you recommend to match the distance of the UHF range? I'm planning on using 10-13dbi directional antenna for the receivers, and cloverleaf for the Txs.

 

[kloner]

My discos use the 500mw and i get good range out to 2 miles, then it slowly fades. there 1 watt stuff i've never hit a limit out to 10 miles in planes.... the 500mw needs a 5v power supply, the 1 watt are 12v and needs a power supply as well. I've always used the tried and true "buck converter" for that

http://www.amazon.com/gp/offer-list...sr=1-14&keywords=buck+converter&condition=new

here is a wing with distance telemetry and you can see it's range. When i'm near the homes you see wifi interference then i run off into no mans land.... it generally tends to be range dependent since wifi isn't very strong it's minimal where i fly

 

[Noah410]

My discos use the 500mw and i get good range out to 2 miles, then it slowly fades. there 1 watt stuff i've never hit a limit out to 10 miles in planes.... the 500mw needs a 5v power supply, the 1 watt are 12v and needs a power supply as well. I've always used the tried and true "buck converter" for that

http://www.amazon.com/gp/offer-list...sr=1-14&keywords=buck+converter&condition=new

here is a wing with distance telemetry and you can see it's range. When i'm near the homes you see wifi interference then i run off into no mans land.... it generally tends to be range dependent since wifi isn't very strong it's minimal where i fly

Well my goal for my build is to have a minimum of a 5 mile range, so I guess I'd be going with a 1W vTx. I watched the video (which was pretty entertaining), and I see what you mean. The only thing I don't particularly like is the fuzziness of the footage. I know that you wern't using anything fancy like a DJI lightbridge, but if I were to strap an HD camera (like a 1080p remote mount camera, or most likely a fatshark pilot HD). Would the image clear up a bit through down-scaling? The only reason I'm worries about this is because I fly in places where power lines are an issue, and I'd like to be able to see them before I'm right next to them. And on that note, I'm not doing anything crazy like flying through them. I'm just concerned because I was doing a job for a golf course, and there were power line running across the green, and my board-cam on my Discovery couldn't pick them up until I was on top of them.

Thanks

 

[kloner]

theres two things resulting in that your seeing the camera is a 420 line,,,, that is PZ-0420 and i hated it something fierce. The other thing you see is the SD recording in 720-480 on the ground station..... but the camera sucked

Here is 2.4 not so much range but with a pz-0513 and it's way better.... i love my 2.4 systems so much more than my 5.8 (we run em all) i've never just had it go snow that i couldn't fly through like the 5.8 does often...

 

[Noah410]

theres two things resulting in that your seeing the camera is a 420 line,,,, that is PZ-0420 and i hated it something fierce. The other thing you see is the SD recording in 720-480 on the ground station..... but the camera sucked

Here is 2.4 not so much range but with a pz-0513 and it's way better.... i love my 2.4 systems so much more than my 5.8 (we run em all) i've never just had it go snow that i couldn't fly through like the 5.8 does often...

Ah, I see. I'm planning on using a Fatshark pilot HD V2 for the pilot camera, which should bring me some good quality video. Thanks for all the help, and look out for my other questions that I might have on my upcoming build.

Thanks