FPV HUB

General Category => General Discussion => Topic started by: ak47 on May 14, 2011, 06:31:42 PM

Title: Bad vibes !
Post by: ak47 on May 14, 2011, 06:31:42 PM
All

Found this thread on a web site when surfing this afternoon....

http://www.largemodelassociation.com/viewtopic.php?f=6&t=1954 (http://www.largemodelassociation.com/viewtopic.php?f=6&t=1954)

Now im pretty new to the fpv game but havnt these guys got some of there facts wrong about the legalities etc of FPV.

Ant

Title: Re: Bad vibes !
Post by: Njoro on May 14, 2011, 09:13:03 PM
 :o "If you stick your head up an elephants a£$%&ss you couldn't come up with so much sh*(***&^%it".
Title: Re: Bad vibes !
Post by: Coyote on May 14, 2011, 09:19:02 PM
Lol, oh another 1, let em get on with it. Same sh1t, same unfactual crap, they wont listen.

Watch as the thread goes alone, people who do know what they are on about pitch in, then discredit the authors. Then it becomes yet another epic fail lol
Title: Re: Bad vibes !
Post by: bogbeagle on May 16, 2011, 10:36:45 AM
Just took a look at that LMA site.



I noticed this comment, early on in the thread ...


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.


Not 100% sure, but I think that this is pure supposition ... not to imply that unfounded assertions have no place on the internet  ;D


I'm not a true FPVer, but I have dabbled a bit. One of my experiments involved a 2watt Vtx and a Spektrum setup ... on the living-room floor. Try as I might, I could not interrupt the Spektrum link. Now, when I did the same experiment with the 2W Vtx and my 35 Meg gear ... all hell broke loose. I've no idea whether those results accord with the real-life experiences of the FPV' community. Just my "2 Cents"


Did you notice that the contributor, Glenn Masters, injected a bit of sanity into the witch-hunt?  He suggested that the likely reason for the crashes was pilot error ... still up there as the Number 1 cause of aircraft' demise.


Then, there was the usual uninformed crap about insurance.  More sinister was the implied intent to "appeal to authority" ... that is, to ask the CAA to "do something".


Title: Re: Bad vibes !
Post by: mattydred on May 16, 2011, 10:50:29 AM
i noticed this reply in the link

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

Andy Boylett
     
 

Title: Re: Bad vibes !
Post by: Njoro on May 16, 2011, 11:05:51 AM
Look at what Andy says, 2.4 everywhere.

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

cheers, Andy

http://www.largemodelassociation.com/viewtopic.php?f=6&t=1954 (http://www.largemodelassociation.com/viewtopic.php?f=6&t=1954)


WiFi hot spot.

:opps: posted at the same time.
Title: Re: Bad vibes !
Post by: Pasty on May 16, 2011, 01:11:33 PM
I'm so bored of this kind of twoddle...

UK pilots need to fly within the regs and reframe from putting up videos if there is any doubt that the flight goes ouside the boundrys in any form.

Its all fuel for the fire at the moment.

I would suggest not using 2.4 either, that way the main bulk of mud slinging is dealt with.
Title: Re: Bad vibes !
Post by: g.collins on May 16, 2011, 01:52:17 PM
But um, well um, (?) can't think of nothing good to say about this, :( you are always going to get people moaning whatever you do, whether they are uneducated of FPV and don't now what there talking about or not.
Just   ;D and leave them to it.
Gordon
Title: Re: Bad vibes !
Post by: Swissnic on May 16, 2011, 01:56:47 PM
I wouldn't use 2.4Ghz anyway - it's swamped with all sorts of broadcasts - not just RC, but WLAN, Cordless Phones, Security Cams etc...  We have plenty of legal Frequencies to choose from which arn't swamped...  459/1.3/5.8 that the Old BMFA geriatrics havent discovered yet...

Title: Re: Bad vibes !
Post by: Coyote on May 16, 2011, 02:12:37 PM
459 and 1.3 are not legal frequencies to transmit video on
Title: Re: Bad vibes !
Post by: Swissnic on May 16, 2011, 02:40:29 PM
Sorry - I didn't put that very well...

I was trying to say there are enough frequencies for Video _and_ Control without having to use 2.4Ghz...

i.e.  459Mhz + 5.8Ghz

Re. 1.3Ghz - are you sure this isn't a Video channel?
Title: Re: Bad vibes !
Post by: Swissnic on May 16, 2011, 03:11:29 PM
I thought I'd check on 1.3Ghz for video - and came across this!

Ofcom UK Frequency Allocation Table 2010 (the latest I could find)

http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/ukfat2010.pdf (http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/ukfat2010.pdf)

Annex B Table 2 - 10. Model Control

CodeFrequencies or Frequency BandRadiated level
M.126960-27280 kHz100 mW
M.234·945-35·305 MHz100 mW
M.340·66-41·00 MHz100 mW
M.4433·05–434·79 MHz10 mW
M.5458·5-459·5 MHz100 mW

This was a surprise to me - 433Mhz can be used for control legally in the UK!  Okay - 10mW is a bit small - but it's there in black and white on the Ofcom website!

Annex B Table 2 - 16. Wireless video cameras – Non Broadcasting.

CodeFrequencies or Frequency BandRadiated level
V.11389-1399 MHz500 mW
V.22400·0–2483·5 MHz10 mW
V.35725–5875 MHz25 mW

As you can see from these tables, not only video broadcast on 1.3Ghz legal, but it has the highest output of any video source.  The only thing I cant be sure of is the use of 1.3Ghz in the air...  I have just spoken with both Ofcom and the CAA and am awaiting their confirmation...   :P

Nic.
Title: Re: Bad vibes !
Post by: Snagglesworth on May 17, 2011, 07:43:22 AM
Yes it is legal to use 1389 - 1399 MHz but you have two problems

First off, Try and find a transmitter on that frequency. Most of the 1.3 MHz tx's available operate from 12xx - 1360. I've not seen any that sit in the uk band.

Second problem would be it's very narrow (10mhz) so if everyone jumped on to 1389, the channel is going to get very swamped making it next to useless.
Title: Re: Bad vibes !
Post by: Flypoppa on May 17, 2011, 10:20:15 AM
433-434mhz is an amatuer frequency and there are repeaters dotted around the country that are transmitting all the time. (when they are working.) But I feel sure that a lot of you know this.
Where I fly there are 3 or 4 of these not to far away that I can access if I had a mind to.
Title: Re: Bad vibes !
Post by: Swissnic on May 17, 2011, 10:53:26 AM
Snaggles - 2 very good points.

I managed to find one transmitter in the UK range - but they only do 1.5W or 5W outputs...  http://www.rf-links.com/newsite/transmitters/1400.html (http://www.rf-links.com/newsite/transmitters/1400.html).  Regarding the narrow bandwidth - I guess no-one is using these frequencies at the moment, and FPV tends not to be a group sport...  I agree though - this is not a comercial option.

Flypoppa - Are you saying we could actually use the relay stations to increase our control range on 433?
Title: Re: Bad vibes !
Post by: Flypoppa on May 18, 2011, 10:23:17 AM
Swissnic. No. What I am saying that there would be interference. The input frequency of these is 433 + a few KCs. The output is 434 + a few KCs. In most cases they are off untill one transmitts a tone or code. But every 15 minutes they do transmitt a callsign. So if in the area and on their frequency... One FPV lawndart. :o
Title: Re: Bad vibes !
Post by: Swissnic on May 18, 2011, 10:27:43 AM
Ah - I see what you mean...  Luckily most of the 433mhz control systems out there are frequency hopping spread spectrum...  I am assuming this would get around this callsign transmissions?
Title: Re: Bad vibes !
Post by: Flypoppa on May 18, 2011, 10:48:35 AM
Quote from: Swissnic on May 18, 2011, 10:27:43 AM
Ah - I see what you mean...  Luckily most of the 433mhz control systems out there are frequency hopping spread spectrum...  I am assuming this would get around this callsign transmissions?
Yes it would. As I said they TRANSMITT of 434mhz, only RX on 433. The chances of anyone tranmitting close to you on 433 would be rare.
In my area it is almost dead. Very few players.