Dragon Link UHF system

[JezUK1]

When people talk about the Dragon Link UHF system is that for the video link or simply controlling the plane? Also is it legal in the UK?

[Flyn]

Hi fella,

It is a rc control system that runs on 433mhz only - non uk legal! It is vastly over power & on a illegal frequencey for rc control here in the uk.

If you use it you risk being brought down by ham radio users & cheap walkie talkies!! Not mention you'll be breaking uk law - ofcom will hunt you down ;)

Look into ezuhf & Open LRS, both of which have uk legal 459mhz firmware for UHF rc control systems.

As for video, most people use 5.8ghz (5800mhz) as a transmission frequency, this allows them to continue to use 2.4ghz for their rc control without any interference (or 35mhz, 459mhz). People mostly use tech from immersion rc or fatshark, & foxtech plus it's many clones (rebrands).

Immersion rc & fatshark are compatible units so you can use a combination of the immersion rc & fatshark vtx (video transmitter) & vrx (video receiver) to get video, however they both make vtx's at illegal power levels.

The uk legal limit for 5.8ghz is 25mw of power. Immersion rc do a vtx at this power.

However the cheaper & popular foxtech units are totally illegal over here, they transmit outside the uk allocated 5.8ghz frequencey bands as well as at illegal power levels. These units are not compatible with immersion rc or fatshark, and will land you in massive trouble with ofcom if you get caught using them.

You can find these units all over eBay & are branded with many different names for import from china.

Some people use 2.4ghz for video, this allows for slightly better signal penetration of obstacles, trees clouds etc, this does mean however you need to ditch your 2.4ghz rc control system in favour of a 35mhz transmitter or a 459mhz one. Also if anyone near you turns on their 2.4ghz rc control transmitter while you're flying it will do a great job of blinding you, knocking out your video, wifi routers can also have an effect in populated areas.

So 2.4ghz video users usually fly alone out in the wilds. Legal uk power levels for 2.4ghz vtx's is 10mw.

Hope that helps, & over answers your question ;)

[Coomkeen]

Thanks for that excellent explanation Flyn :)
I'm not exactly a beginner in radio, or rc, but knowing immersion and fat shark compatibility for example is valuable info.

A question though...
I'm seriously thinking of going 'back' to 35MHz for rc control, but would really miss the telemetry of the Jeti 2.4GHz conversion I have fitted to a Cockpit SX.
Is there any separate system I could use for equivalent data feedback?

Ron

[Zeeflyboy]

Telemetry such as voltage etc?

Just use an OSD for all the planes vital statistics - all the info will be right there infront of your eyeballs.

[Flyn]

Hi mate, glad the above was helpful.

Info like that is usually scattered far & wide on the net with bits & bobs in many different threads.

Personally I think that sort of explanation should be a sticky or somit on the forum page for people to look at, a data sheet info fpv maybe?

Coyote if you're listening - what do you think, it would help many starting out, choosing kit & staying legal. (unless we already got one & I've just missed it!) EDIT: Or not staying legal - their choice.

As for telemetry most fpv flyers use OSD's (I use Eagle Tree OSD Pro), these On Screen Displays can display & record all flight telemetry data for the user in real time. My ET (eagle tree) is a great bit of kit, it has all the telemetry I need, I can get a live data feed in mid flight to a seperate laptop screen as well as on my goggles - it also records every piece of data that goes through the system for later review & detailed analysis, even allowing a 3 dimensional flightpath to be drawn in google earth. Amazing!

Other systems are available too but I'm loving my ET kit!

It displays & logs:

GSP Speed, direction, height, location, bearing, sats
Battery voltages, mah consumption, live amp draw
Home direction, distance
Climb rate
Rssi (rc signal strength)

You can add other sensors for most other needs too!

Oh it can also stabilise & auto level your plane & RTH (return to home) if you ever loose contact with it, either automatically in the event of rc signal lose or manually If you loose video.

A bit pricy but worth every penny if it saves your plane just one time!

[Flyboysee]

Hi fella,

It is a rc control system that runs on 433mhz only - non uk legal! It is vastly over power & on a illegal frequencey for rc control here in the uk.

If you use it you risk being brought down by ham radio users & cheap walkie talkies!! Not mention you'll be breaking uk law - ofcom will hunt you down ;)

Look into ezuhf & Open LRS, both of which have uk legal 459mhz firmware for UHF rc control systems.

As for video, most people use 5.8ghz (5800mhz) as a transmission frequency, this allows them to continue to use 2.4ghz for their rc control without any interference (or 35mhz, 459mhz). People mostly use tech from immersion rc or fatshark, & foxtech plus it's many clones (rebrands).

Immersion rc & fatshark are compatible units so you can use a combination of the immersion rc & fatshark vtx (video transmitter) & vrx (video receiver) to get video, however they both make vtx's at illegal power levels.

The uk legal limit for 5.8ghz is 25mw of power. Immersion rc do a vtx at this power.

However the cheaper & popular foxtech units are totally illegal over here, they transmit outside the uk allocated 5.8ghz frequencey bands as well as at illegal power levels. These units are not compatible with immersion rc or fatshark, and will land you in massive trouble with ofcom if you get caught using them.

You can find these units all over eBay & are branded with many different names for import from china.

Some people use 2.4ghz for video, this allows for slightly better signal penetration of obstacles, trees clouds etc, this does mean however you need to ditch your 2.4ghz rc control system in favour of a 35mhz transmitter or a 459mhz one. Also if anyone near you turns on their 2.4ghz rc control transmitter while you're flying it will do a great job of blinding you, knocking out your video, wifi routers can also have an effect in populated areas.

So 2.4ghz video users usually fly alone out in the wilds. Legal uk power levels for 2.4ghz vtx's is 10mw.

Hope that helps, & over answers your question ;)

Flyn, that seems a very comprehensive (and quite depressing) view of the laws. May I ask, how are you managing with 25mw on your ZII? Or have you gone for the 10mw on 2.4?

[CurryKitten]

There's been a relaxation of the rules since the forum separated out from fpvuk.  While there's plenty of rules in FPV that are good ideas, I don't think that reciting the legal limits of 5.8 and 2.4 does anyone any favours... and I struggle to think of anyone here that flies on them (whether they choose to admit it or not)

So do we really need a "staying legal" section, when what would be more appropriate is a "typical setup" advise based on what different people in the forum already use ?

[Flyn]

Hi fella,

Yes it can seem like that, but you can go a about 1/2 mile with the right antenna on the ground - 16dbi patch with tracking.

[CurryKitten]

I'm not saying you can't - you can get astonishing distances with 25mw with the right antenna combos and tracking

I don't believe it represents a typical setup though.

[Flyn]

It's about about making an informed choice, some people may wish to fly totally legally, others may just want the most powerful vtx they can get for as little as possible & to hell with the law.

But with a info page or datasheet at least they could make an informed choice & have all the relevant data to hand.

Like when I started I didn't know that the foxtech/BEVRC kit transmitted outside the uk 5.8 bands or what power levels I could use. It may not be helpful for you but it might help someone on their near vertical learning curve that is FPV. Then they can choose weather they want to buy 25mw or 600mw, or import a cheap chinese vtx whilst being fully aware of their decision.   

To be honest I think the levels are too low & in fact cause more of a danger than using a higher power vtx would, as 5.8 dissipates quite quickly at range it wouldn't effect anyone if you use more power.

For most people it's not about max range - it's about link quality, more power equals better video link which equals safer flying with no video loses & crashes etc etc....

[Flyn]

Also if you're using FPV or at least VTX's on a hex or heli for commercial work you need to know & use the legal limts of video transmitters.

[Coomkeen]

Thanks, will have to look at the ET kit.
My 'problem' at the mo, is no goggles, no camera, no VTx.
And it will take good few more pension cheques before that is sorted.
Meanwhile, time to get the aircraft flying, trimmed out (ok I know that will change with the video gear) and controllable using the 'back to the future' 35MHz gear.
And telemetry would be good, but with no VTx or goggles etc.....

Never mind, onward and definitely upward :) :)


Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com

[Flyn]

Thanks, will have to look at the ET kit.
My 'problem' at the mo, is no goggles, no camera, no VTx.
And it will take good few more pension cheques before that is sorted.
Meanwhile, time to get the aircraft flying, trimmed out (ok I know that will change with the video gear) and controllable using the 'back to the future' 35MHz gear.
And telemetry would be good, but with no VTx or goggles etc.....

Never mind, onward and definitely upward :) :)


Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com

Ahh, ok I see. Not having any of that stuff can hamper buying an osd. I must say if you need to buy that gear first I'd probably hold off on the eagle tree stuff, there are cheaper osd's on ebay that will do a basic & very good job, maybe take a look at those too??

I seem to remember reading something about a UHF 433 telemetry system. This might be worth doing a google search for - can anyone else help here?

not sure if legal here, but it should be as it's not for rc control

[CurryKitten]

It's about about making an informed choice, some people may wish to fly totally legally, others may just want the most powerful vtx they can get for as little as possible & to hell with the law.

But with a info page or datasheet at least they could make an informed choice & have all the relevant data to hand.

Like when I started I didn't know that the foxtech/BEVRC kit transmitted outside the uk 5.8 bands or what power levels I could use. It may not be helpful for you but it might help someone on their near vertical learning curve that is FPV. Then they can choose weather they want to buy 25mw or 600mw, or import a cheap chinese vtx whilst being fully aware of their decision.   

To be honest I think the levels are too low & in fact cause more of a danger than using a higher power vtx would, as 5.8 dissipates quite quickly at range it wouldn't effect anyone if you use more power.

For most people it's not about max range - it's about link quality, more power equals better video link which equals safer flying with no video loses & crashes etc etc....

I absolutely agree with everything you've said.  So I think, yep do a sticky somewhere about whats available - and pros/cons of each, along with some examples of what people have chosen, why they chose it, and what results they get. 

Is Coyote reading this... if so, what's your opinion ?

[Coomkeen]

Thanks, will have to look at the ET kit.
My 'problem' at the mo, is no goggles, no camera, no VTx.
And it will take good few more pension cheques before that is sorted.
Meanwhile, time to get the aircraft flying, trimmed out (ok I know that will change with the video gear) and controllable using the 'back to the future' 35MHz gear.
And telemetry would be good, but with no VTx or goggles etc.....

Never mind, onward and definitely upward :) :)


Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com

Ahh, ok I see. Not having any of that stuff can hamper buying an osd. I must say if you need to buy that gear first I'd probably hold off on the eagle tree stuff, there are cheaper osd's on ebay that will do a basic & very good job, maybe take a look at those too??

I seem to remember reading something about a UHF 433 telemetry system. This might be worth doing a google search for - can anyone else help here?

not sure if legal here, but it should be as it's not for rc control

Thanks Flynn,

Think it should be 459(?) over here. Is that right?
But a 'stand alone' telemetry system might make sense anyway.

Thanks again.


Ron

EI8GMB - G6IWK
www.bandonmodelflyingclub.com