FPV Interference on 2.4Ghz

The latest information and advice on installing and using 2.4 Ghz systems in over 20 Kg model aircraft
Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

FPV Interference on 2.4Ghz

Postby Andy Boylett » February 22nd, 2011, 11:27 pm

Has any thought been given to the rapidly developing issue of ilegal fpv (first person video) fliers. These are small aircraft (or helis) that are flown with a camera transmitting back to the pilot. The pilot flies only looking at his video screen and can fly at times up to 2 miles from where he is stood. The issue is that many of the video transmitters being bought are ilegal and transmit at 1000mw which is way above the UK 100mw limit. The reason these fpv guys like to use the higher power is simple - they can fly further away without risking losing their video link and hence model.

The reason there is interference is because the flying model is the source of transmission. If you are flying and one of these planes happens to fly towards where you are, it will swamp the 2.4Ghz channels. One of my local clubs lost 2 planes in the last few weeks due to the one fpv craft - which has now been tracked down. The club has bought a 2.4Ghz scanner that shows the power level at each frequency. It is dead easy to see Futaba and Spektrum footprints and then of course the fpv.

There is lots of discussion starting on the big forums re this issue. There does not seem to be very much that can done legal wise to stop the fpv's.

It wouuld look to me that some pretty good 2.4Ghz scanners are essential for the shows....then if an 'incomming' fpv signal is seen we call emergency landings.

Thoughts?

Bob Thompson1894
Posts: 822
Joined: December 6th, 2008, 1:08 pm
Location: Notts
Contact:

Re: FPV Interference on 2.4Ghz

Postby Bob Thompson1894 » February 23rd, 2011, 12:18 am

somebody remind me why we need 2.4 for the shows, then.....?

paul hughes
Posts: 234
Joined: December 8th, 2008, 8:10 pm
Contact:

Re: FPV Interference on 2.4Ghz

Postby paul hughes » February 23rd, 2011, 11:16 am

If the camera system transmits on 2.4 ghz at 1000mw, and that will swamp all 2.4 ghz model rc systems, what system does the aircraft carrying the camara use?
If anyone is interested in these illigal camaras they are being advertised by Hobbyking (PRODUCT ID: CP100024RX12T)

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 23rd, 2011, 12:50 pm

paul hughes wrote:If the camera system transmits on 2.4 ghz at 1000mw, and that will swamp all 2.4 ghz model rc systems, what system does the aircraft carrying the camara use?
If anyone is interested in these illigal camaras they are being advertised by Hobbyking (PRODUCT ID: CP100024RX12T)


Paul,
HobbyKing is based in China and sells to the whole world. It is up to the buyer to obey the law. The biggest selling fpv systems have special websites selling them - dead easy to find on google. They transmit on 100, 350, 500 and 1000mw. Only 100mw legal in uk.
http://www.eagletreesystems.com/osd/osd-pro.htm
http://www.fpvsystems.com/
http://www.readymaderc.com/store/index.php?main_page=index&cPath=4
There everyone can break the law now :D :D :D

As for your question above...The thinking on the forums is...the fpv systems broadcast simultaneously on 4 frequencies, together, in a wideband format. If you look at these with a scanner it takes a out a huge block of 2.4Ghz. The plane being flown is turned on after the fpv has been initiated. The planes control transmitter now scans what is available and makes it choice (either 2 fixed frequencies for DSM or a range to hop along for the others). Hence this flier is ok. The issue is for others already flying when this 'frequency blocker' comes barging in.

The issue has only relatively recently been identified and the specific examples are just starting to appear on the forums.

chris_bell
Posts: 15
Joined: January 7th, 2009, 3:26 pm
Location: North Lincs
Contact:

Re: FPV Interference on 2.4Ghz

Postby chris_bell » February 23rd, 2011, 1:02 pm

Where did you get the scanner from ?

chris

Glenn Masters
Posts: 89
Joined: January 3rd, 2009, 12:02 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Glenn Masters » February 23rd, 2011, 6:57 pm

God Almighty !! I think i'm gonna stop at home where its safe . . .

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 23rd, 2011, 7:55 pm

chris_bell wrote:Where did you get the scanner from ?

chris

Hi Chris,
Not sure, it is a lttle club near Redcar and our leader went out and got it. It was £70 I think and can be downloaded into a pc to show total spectrum analysis over time.
I'll find out which one it is if you want to know.

We fly next to a housing estate and one of our thoughts is that someoen might be doing this deliberately. :(

cheers, Andy

Bob Thompson1894
Posts: 822
Joined: December 6th, 2008, 1:08 pm
Location: Notts
Contact:

Re: FPV Interference on 2.4Ghz

Postby Bob Thompson1894 » February 23rd, 2011, 10:17 pm

This could very well be history repeating itself, I remember flying quite properly on 27mhz when the pirates took over. Then we got 35, no problems. 2.4? Is it going to be poisoned with illegal radios? Maybe we jumped too soon...

chris_bell
Posts: 15
Joined: January 7th, 2009, 3:26 pm
Location: North Lincs
Contact:

Re: FPV Interference on 2.4Ghz

Postby chris_bell » February 24th, 2011, 12:51 pm

Andy Boylett wrote:
chris_bell wrote:Where did you get the scanner from ?

chris

Hi Chris,
Not sure, it is a lttle club near Redcar and our leader went out and got it. It was £70 I think and can be downloaded into a pc to show total spectrum analysis over time.
I'll find out which one it is if you want to know.

We fly next to a housing estate and one of our thoughts is that someoen might be doing this deliberately. :(

cheers, Andy


Yes please Andy, we have a show this year - sounds like it would be very interesting to "see" whats happening. Besides it'll give TX controll something to do besides look after the half dozen 35 Mhz TX's.

Chris

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 24th, 2011, 12:58 pm


Robin Woodhead
Posts: 70
Joined: December 3rd, 2008, 5:23 pm
Location: Nottingham
Contact:

Re: FPV Interference on 2.4Ghz

Postby Robin Woodhead » February 26th, 2011, 6:58 pm

Andy Boylett wrote:Has any thought been given to the rapidly developing issue of ilegal fpv (first person video) fliers. These are small aircraft (or helis) that are flown with a camera transmitting back to the pilot. The pilot flies only looking at his video screen and can fly at times up to 2 miles from where he is stood. The issue is that many of the video transmitters being bought are ilegal and transmit at 1000mw which is way above the UK 100mw limit. The reason these fpv guys like to use the higher power is simple - they can fly further away without risking losing their video link and hence model.

The reason there is interference is because the flying model is the source of transmission. If you are flying and one of these planes happens to fly towards where you are, it will swamp the 2.4Ghz channels. One of my local clubs lost 2 planes in the last few weeks due to the one fpv craft - which has now been tracked down. The club has bought a 2.4Ghz scanner that shows the power level at each frequency. It is dead easy to see Futaba and Spektrum footprints and then of course the fpv.

There is lots of discussion starting on the big forums re this issue. There does not seem to be very much that can done legal wise to stop the fpv's.

It wouuld look to me that some pretty good 2.4Ghz scanners are essential for the shows....then if an 'incomming' fpv signal is seen we call emergency landings.

Thoughts?



Hitec Aurora 9 in scan mode resolves this problem, for a demonstration and explanation, view these YouTube links.
http://www.youtube.com/watch?v=AdIhbNLC0yg
http://www.youtube.com/watch?v=R6aNeZ-Dlio&NR=1

Robin

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 26th, 2011, 10:30 pm

Robin Woodhead wrote:Hitec Aurora 9 in scan mode resolves this problem, for a demonstration and explanation, view these YouTube links.
http://www.youtube.com/watch?v=AdIhbNLC0yg
http://www.youtube.com/watch?v=R6aNeZ-Dlio&NR=1

Robin


Robin,
Thanks for the suggestion. However, this does not help the problemat an airshow when people use lots of different systems.
Also, I have not seent the Aurora 9 tested against an fpv system comming into its range - which is what the worry on forums is about....are the frquency hopping systems capable of hopping when a whole block of frequencies has been swamped?

The Spektrum test of their new 'hopping' system with 100 transmitters together is interesting, but they still haven't whown that they cope with an fpv.

Regards
Andy

Robin Woodhead
Posts: 70
Joined: December 3rd, 2008, 5:23 pm
Location: Nottingham
Contact:

Re: FPV Interference on 2.4Ghz

Postby Robin Woodhead » February 26th, 2011, 11:24 pm

If you look at the second video, it shows how it responds to an AV transmission on 2.4 Gh.

Robin

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 26th, 2011, 11:58 pm

Robin Woodhead wrote:If you look at the second video, it shows how it responds to an AV transmission on 2.4 Gh.

Robin


Hi Robin, I did look at that video, but that is not the issue. Each of the manufacturers seem to be very careful how they present their wares. That guy switches video on first, then lets the Hitec system scan to find a nice clear area of frequencies. In fact, the sequence he shows is what the fpv guys do in order not to have the flying system interfere with their video link (because it picks different frequencies).

The issue with fpv is that they can fly a long way from where they are stood. hence you turn on your Hitec transmitter and it cannot 'hear' the fpv which is a long way off. You then take off and while you are flying the fpv flies a mile or so closer to you. Now the fpv signal comes into range and can be right over the top of the frequency set chosen by your transmitter.

You need to find a test where the transmitter is on and then fpv signal comes trotting along - and the fpv we have seen locally is not any old fpv, it is a high power, 1000mw that floods 4 adjacement bands.

Regards, Andy

Glenn Masters
Posts: 89
Joined: January 3rd, 2009, 12:02 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Glenn Masters » February 27th, 2011, 1:10 pm

Having digested all the above postings on this thread (and a few more from other threads elsewhere on the forum) It seems to me that the advent of 2.4 Ghz has been a godsend to the "shortcomings" of our old friend, the 35meg system. However, the poor old pilot and avid forum contributor, faced with the possibility of an unexplained and unplanned "arrival" may well find himself in a quandery . . . Picture our pilot, if you will, on his favourite flying patch - transmitter in hand - aircraft deep in the dust . . He looks accusingly to the right, then to the left, and then eventually to the heavens - what is he to do ? He can no longer blame his troublesome old ludite 35meg radio system, he cant even blame the possibility of succumbing to someone else with their old 35meg radio . . . He could consider a possible mechanical failure, he could re-evaluate his skills as a builder, he could even - heaven forbid - realise he might have exceeded his own piloting skills resulting in an untimely end to his current and "best ever" aircraft . . . . .
Personally, I have a long career of crashing aeroplanes - some of them very expensive ones - but in all those cases I have been happy to realise that it was as a result of some explainable reason, usually of my own doing. The danger is, if we persue ever more vague possibilities and potential "reasons" for loosing our aircraft, we will be left wandering if it is ever going to be safe for us to fly at all - and it wont just be us wandering, so will the relevant authorities.
regards Glenn Masters 1222
Last edited by Glenn Masters on February 27th, 2011, 1:13 pm, edited 1 time in total.

Alan Cantwell 1131
Posts: 1414
Joined: June 15th, 2009, 8:21 pm
Contact:

Re: FPV Interference on 2.4Ghz

Postby Alan Cantwell 1131 » February 27th, 2011, 1:12 pm

NOW, i am not the best educated with radio thingys, but isnt the range one of these things flys at, goverend by the range of the transmitter? and doesnt BMFA guidlines state sush a unit has to be buddy linked, and the model must be in site of the pilot with the link tranny, by eyesight? its about time we where a tad more legal with this stuff if they are not insured,

now then, sell the DX9, and dig out my old futaba 27mhz gear, me thinks :lol:

Bob Thompson1894
Posts: 822
Joined: December 6th, 2008, 1:08 pm
Location: Notts
Contact:

Re: FPV Interference on 2.4Ghz

Postby Bob Thompson1894 » February 27th, 2011, 1:50 pm

We are not going to stop this. These 'renegades' on high power 2.4 will not join a club, (or the BMFA) they will just go out and do it, until some major catastrophe occurs, and they finish up in court. The whole of model flying will then suffer the consequences of their actions. As long as they can buy the equipment, then they will shrug their shoulders at the law, and fly (out of their sight) with no insurance. It is happening now, despite the fact that it is illegal.
I have reservations about the LMAs insistence on 2.4 for the shows, and think it was a knee jerk reaction which could come back and bite us. Whats next? 4.8? 9.6?

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 27th, 2011, 2:47 pm

Glenn Masters wrote:Having digested all the above postings on this thread (and a few more from other threads elsewhere on the forum) It seems to me that the advent of 2.4 Ghz has been a godsend to the "shortcomings" of our old friend, the 35meg system. However, the poor old pilot and avid forum contributor, faced with the possibility of an unexplained and unplanned "arrival" may well find himself in a quandery . . . Picture our pilot, if you will, on his favourite flying patch - transmitter in hand - aircraft deep in the dust . . He looks accusingly to the right, then to the left, and then eventually to the heavens - what is he to do ? He can no longer blame his troublesome old ludite 35meg radio system, he cant even blame the possibility of succumbing to someone else with their old 35meg radio . . . He could consider a possible mechanical failure, he could re-evaluate his skills as a builder, he could even - heaven forbid - realise he might have exceeded his own piloting skills resulting in an untimely end to his current and "best ever" aircraft . . . . .
Personally, I have a long career of crashing aeroplanes - some of them very expensive ones - but in all those cases I have been happy to realise that it was as a result of some explainable reason, usually of my own doing. The danger is, if we persue ever more vague possibilities and potential "reasons" for loosing our aircraft, we will be left wandering if it is ever going to be safe for us to fly at all - and it wont just be us wandering, so will the relevant authorities.
regards Glenn Masters 1222


Excellent idea :D hadn't thought of that one.....interestingly my son Sam suggested that it might just be the rubbish pilots at our local club and nothing to do with fpv's :o

Andy Boylett
Posts: 445
Joined: October 18th, 2010, 8:09 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Andy Boylett » February 27th, 2011, 2:49 pm

Alan Cantwell 1131 wrote:NOW, i am not the best educated with radio thingys, but isnt the range one of these things flys at, goverend by the range of the transmitter? and doesnt BMFA guidlines state sush a unit has to be buddy linked, and the model must be in site of the pilot with the link tranny, by eyesight? its about time we where a tad more legal with this stuff if they are not insured,

now then, sell the DX9, and dig out my old futaba 27mhz gear, me thinks :lol:


I totally agree. My club has been unable to find an 'authority' that would take action against a 1000mw transmitter user.

Mike altham
Posts: 308
Joined: August 12th, 2010, 11:06 am
Contact:

Re: FPV Interference on 2.4Ghz

Postby Mike altham » February 28th, 2011, 10:37 pm

Hi

As Alan said they should be buddy linked and be in sight of the other pilot.

If you are running 2.4 on the transmitter and rx for the camera. You have to use 35 MHz radio as the 2.4 will swamp the radio 2.4 signal.

There is 5.8 ghz for camera and 433 UHF but this needs a HAM license to use in the Uk plus it is a military frequency I think.

FPV flying is not covered under Bmfa insurance. Little known to some FPVers that you have to get separate insurance which is £15 a year. This covers FPV Flying upto 5 million insurance.
Last edited by Mike altham on May 17th, 2011, 1:47 pm, edited 1 time in total.


Return to “2.4 Ghz and Large Models”

Who is online

Users browsing this forum: No registered users and 0 guests