Author Topic: FPV in IRL  (Read 103042 times)

kankrz

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« on: April 21, 2010, 14:10:11 PM »
Hi Guys
I guess everyones heard about First Person View flight systems. Who knows what kind of Tx devices are legal in Ireland ? How can I get information about Tx restrictions ?
I now that people (around the world) use 900MHz/1W , 1.2GHz/500mW  or 5.8GHz/500mW for video links.
I found a website in UK which offers  2.4GHz  and 5.8GHz Tx/Rx systems and I assume that this devices are legal in UK. Is Irish law similar to UKs  in this matter?

DennisZ

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Re: FPV in IRL
« Reply #1 on: April 21, 2010, 23:21:22 PM »
Quote from: "kankrz"
How can I get information about Tx restrictions ?
I now that people (around the world) use 900MHz/1W , 1.2GHz/500mW  or 5.8GHz/500mW for video links.


only 2.4GHz 10mW TX will be legal in Ireland,
you can use 2.4/500 if you have HAM license.
you can verify that with comreg.ie

also, you will NOT be covered by MACI insurance for this purpose.

kankrz

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« Reply #2 on: April 26, 2010, 02:56:23 AM »
It looks like we can assume that FPV is banned in Ireland. Tx 2.4G/10mW is not sufficient for this purpose. One working FASST futaba transmitter  will successfully block any video on this band.  Additionally, 2.4G video TX cannot be installed  together with 2.4G Rx.

Happy Days

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« Reply #3 on: April 26, 2010, 08:00:38 AM »
Quote
One working FASST futaba transmitter will successfully block any video on this band.


Er,......why? FASST doesn't block anything else, kankrz, so why should it block a video signal? :?:  

I don't understand. :(  please explain :?

Keith
Try not to run out of airspeed, altitude and ideas....... all at the same time.

DennisZ

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« Reply #4 on: April 26, 2010, 10:05:41 AM »
Quote from: "Happy Days"
Quote
One working FASST futaba transmitter will successfully block any video on this band.


please explain :?



no, it would not - potentially, you may miss couple lines of video.
also his last statement is correct - you can't use both radio and video at 2.4GHz - rc receiver will be "flooded" by a transmission of nearby video TX .

our neighbors in UK managed to get this activity organized and *insured*
http://www.bfpvmfa.org/
http://www.firstpersonview.co.uk/myfiles/file/FPVsafety.pdf

the main points are:
- EU law only allows max 10mW airborne video tx
- you have to maintain visual contact with your model
(for reference, at 600m distance 2m model will look like a dot)

FPV is not banned here - you just have to stay within the limits
and (if anything happened) be prepared to pay the damages  as you will not be covered by MACI insurance.

Happy Days

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« Reply #5 on: April 26, 2010, 10:47:14 AM »
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rc receiver will be "flooded" by a transmission of nearby video TX .



Surely that would depend on the amount of separation of the video and rc signals and of the rc receivers image rejection ability..............wouldn't it? :?:

K.
Try not to run out of airspeed, altitude and ideas....... all at the same time.

DennisZ

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« Reply #6 on: April 26, 2010, 11:52:59 AM »
Quote from: "Happy Days"


Surely that would depend on the amount of separation of the video and rc signals and of the rc receivers image rejection ability..............wouldn't it? :?:



Keith, I am not educated enough in RF area , so I can only quote lads from rcgroups - "the safe way is to use 35/72MHz radio with  whateverGHz video link".

Happy Days

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« Reply #7 on: April 26, 2010, 12:20:19 PM »
Hmmmmm, :?:  don’t know Dennis. The 2.4ghz band is ENORMUS, can’t think why there would be a problem. :?:

It will be interesting to hear what kankrz has to tell us about the matter. :D

K.
Try not to run out of airspeed, altitude and ideas....... all at the same time.

DennisZ

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« Reply #8 on: April 26, 2010, 12:38:36 PM »
Quote from: "Happy Days"
can’t think why there would be a problem. :?:



here http://www.rcgroups.com/forums/showthread.php?t=1164899&highlight=flood

posts #13 and #15

DennisZ

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Re: FPV in IRL
« Reply #9 on: April 26, 2010, 14:18:32 PM »
Quote from: "kankrz"
1.2GHz/500mW  


page 29, table 13
http://www.comreg.ie/_fileupload/publications/odtr0271R1.pdf

Video Senders at 1349MHz up to 500mW - perfectly legal here,
if only you can find who makes them :(

still, you will have to obtain the license to use that
and it will be restricted to use only within a particular area
(if any local farmer already got such license in area where you live - you will not get it).

the info above is from comreg, I had a chat with them couple years ago.

kankrz

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« Reply #10 on: April 27, 2010, 05:07:33 AM »
''It will be interesting to hear what kankrz has to tell us about the matter.''

What are you laughing at ? I really don't understand .The problem is that TX and Rx cannot be to close. Strong Tx signal will stop up/look  Rx.
You loose control after a few meters  flight. How do I know ?  From people who tried to do this.  Reportedly , FASST from futaba cause big problems. The only useful band is 1.2 or 1.3G.

Best regards

Happy Days

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« Reply #11 on: April 27, 2010, 07:44:03 AM »
Hey kankrz, I’m not laughing….I’m just asking a question. :?:


The Futaba FASST  system ‘channel hops’ within a range of frequencies. The signal only stays on one frequency for a few thousands’ of a second before it moves off to another one.

I don’t quite understand what you mean when you say that a strong Tx signal will stop up/look Rx. What do you mean by that? :?  (Sorry for being dumb, but I was born at a very early age!)

The problem you’re speaking of seems to be one of what’s called “Co-channel interference” But with modern digital signals I wouldn’t have thought this would have been a problem.
i.e. Mobile phones use Tx and Rx that are very close together without any problems at all. Admittedly a video signal is a few Megahertz wide and an audio one is only a few Kilohertz wide, but the principle is the same.

People make many strange claims as to why their models crash. :oops:  I’m not saying that a problem with video links doesn’t exist, but I’m curious to hear a rational/specific answer as to why, rather than just generalized statements.

Keith
Try not to run out of airspeed, altitude and ideas....... all at the same time.

kankrz

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« Reply #12 on: April 29, 2010, 06:55:39 AM »
I can only say what I heard from people who tried to place video Tx and model Rx on board (close together). Please take under review that Video Tx are not perfect and have problems with frequency drift, temperature frequency drift etc.  A few meters distance is OK but few centimeters is not enough.  That is way flayers use 1.2G or 1.3G for video. 2.4 is not good for crowded places.
When you ask about FASST system , you're absolutely right but even that you will not see anything if this kind of  Tx works close to you. This is from practice experience (not mine I have to stress).
I have just order Eagle Tree OSD and telemetry system for my 3.3m glider. The issue of Tx for video is still open. I am going to use 35MHz system and probably 2.4G. Wicklow Mountains is the place where I am going to fly. I'll let you know , be patient :)

best regards

PS sorry for my English

Happy Days

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« Reply #13 on: April 29, 2010, 07:44:07 AM »
Good luck kankrz, :clap:  and do please tell us know how you get on with your system. :D

Keith
Try not to run out of airspeed, altitude and ideas....... all at the same time.

IceWind

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« Reply #14 on: April 29, 2010, 23:38:38 PM »
Hi kankrz,

I'm very pleased to see more ppl interested in FPV in IE. :)
As a big fan of AP I couldn't be more happy.

As for gear to use and putting aside legislation.
The best choice would be to have the TX/RX in 440Mhz ( there are some excellent kits that can go up to 5km or even more) and video on 2.4Ghz.

Of course having radio and video on 2.4Ghz is totally out of the question most of my friends that do FPV use is 900Mhz on video and radio on 2.4Ghz.

Btw let me know how good is the EagleTree OSD, I already have the eLogger and was thinking to get their OSD as well.


Nando
..Nando