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Re: FPV backpack

PostPosted: Mon Feb 27, 2012 4:52 pm
by RCModelReviews
Yes, the frequencies are the same as the FoxTech 5.8GHz systems which means they're *not* the same as the Immersion RC systems.

Re: FPV backpack

PostPosted: Tue Feb 28, 2012 9:11 pm
by TailspinTommy
Ah ok,

Those channels are illegal here in the uk...

Re: FPV backpack

PostPosted: Wed Feb 29, 2012 1:13 am
by RCModelReviews
The problem is that FPV is probably illegal everywhere (regardless of the frequencies) -- if you dig deep enough.

One advantage of the little 5.8GHz modules I'm using is that they're not on the same frequencies that 5.8GHz routers and cordless phones are using so you're less likely to encounter (or cause) interference. And, given that we're talking minute amounts of power that are quickly absorbed by the environment, it's rather unlikely your FPV transmitter will interfere with anything else outside a 750m radius.

I certainly believe that we ought to observe the law but i also believe that pragmatism and commonsense would make laws unnecessary in the first place.

Some of the poor guys in Europe have no chance of doing any FPV because the restrictions on their bands are so massive that they're limited to just a few mW on the 5.8GHz band and not much on anything else.

However, despite the fact that so many people are obviously flying FPV (illegally), there have been no reported incidents or issues with the use of this gear. That (to me) indicates that our tiny, low-powered transmitters aren't a threat to existing services on the bands where they're used.

Having said that -- i would never contemplate seriously using some of the 900MHz band because around here, some of it is used for GSM phones and the rest is for aircraft navigation systems. I don't want to lose my video signal to someone sending an SMS and I don't want to be responsible for a commercial airliner plunging into the ocean somewhere.

From that perspective, I believe 5.8GHz is the most suitable band for FPV for a number of reasons:

1. the gear is small and light
2. the range is automatically limited by the environment so potential for affecting other services is minimal
3. in most countries, 5.8GHz is used for radiolocation, amateur or fixed satellite communications so is unlikely to clash with FPV use.
4. 5.8GHz FPV transmitters tend to be of limited power (200mW-500mW) so has limited potential to interfere with other users of this part of the RF spectrum.

Also, in most cases (wireless LAN aside), 5.8GHz systems tend to be used with highly directional antennas which means that the potential for interference between FPV and other services is even more limited.

I'm not advocating that people break the law -- but I am saying that with careful, commonsense attitudes and practices, the potential for any conflict with other services on this band is very, very low -- as has been proven by the number of people already using this gear without "the powers that be" or other users of the same band even knowing that such use is going on.

Re: FPV backpack

PostPosted: Fri Mar 02, 2012 9:31 am
by TailspinTommy
Well Europe in general seem to have accepted FPV and DIY UAV, this is a fairly recent big turn-around from previous laws where there was
a total ban on up controlled airframes.
Think this may have changed due to pressure from the commercial side as more private companies develop UAV systems (for government departments) and
require the ability to perform field testing without restrictive legislation (other than some general do's / don'ts).

The various frequency allocations here is a much older concept where we were allocated non-rest-of-the-planet channels and severely limited in transmitting power.
Typ:
2.4g max = 10mw
5.8g max = 25mw
And that is fairly universal throughout Europe for video transmissions.

While I agree generally with your reasoning, from a personal standpoint I would be much happier to exceed the max allowed power output, (While on a legally allocated freq). Rather than on a legal power output while on a illegal frequency.

The foxtech standard is I believe band E which if memory serves me right then its only legal in the far east, although some of these rf units can be modified to work on other channels, ie Band A & or B .which are legal in the US and Europe.

Re: FPV backpack

PostPosted: Fri Mar 02, 2012 2:34 pm
by BillGriffiths100
The various frequency allocations here is a much older concept where we were allocated non-rest-of-the-planet channels and severely limited in transmitting power.
Typ:
2.4g max = 10mw
5.8g max = 25mw
And that is fairly universal throughout Europe for video transmissions.

Re: FPV backpack

PostPosted: Sat Mar 10, 2012 10:57 pm
by baggus
Are there any parts lists / schematics available yet? (if not, what's the progress on this?)

In one of the youtube videos I recall hearing something about building your own 5.8GHz diversity receiver, any news on that?

Re: FPV backpack

PostPosted: Sun Mar 11, 2012 2:39 am
by RCModelReviews
Testing the diversity receiver this week. DIY backpack build video should also be this week (depending a little on the weather).

Re: FPV backpack

PostPosted: Wed Mar 14, 2012 5:51 pm
by T3PRanch
TX5823 200mW 5.8G module in hand and standing by. Bruce are you building a module based receiver or using a commercial one? I have a RX5808 receiver module as well.
I don't know where you have sourced your modules but they are pretty low cost here: http://www.hktdc.com/sourcing/showrooms ... ter-Module

Thurmond

Re: FPV backpack

PostPosted: Wed Mar 14, 2012 9:42 pm
by RCModelReviews
That crowd's prices look good -- until you factor in the price of a TT or WesternUnion payment :-(

I'll be putting the full article and video up shortly -- with links to where I get my modules (at a reasonable price with excellent delivery times and credit-card or PayPal payment).

Re: FPV backpack

PostPosted: Thu Mar 15, 2012 2:33 am
by T3PRanch
They do PayPal (at least they list PP as an option on some items) also Bruce, although I would trust your sources over those I have not done business with.

Thurmond