New JRX9303 2.4 Gig - legal power in UK or not???

[ChrisB]

The way i read it,the problem is with some US sold units that are labelled as Ok for the EU,,,EU supplied units with the CE stickers should be OK,,,,be interesting to hear Horizons answer though..

[raptorheli2]

righto, i called as promised and they have said as long as purchased in UK then the power output will be ok.

if you never purchased from a reputable dealer or fear it's an import then contact them and they will tweak the radio power output.

good news for the ones who purchased here and hopefully sheds some clarity for the ones who like me had heard different.

cheers

[Sesame]

Surely though the uk ok ones are going to carry the CE sticker where imports probably won't, or is there a chance that even those carrying the stickers may not be legit UK versions? ifthat makes any sense.

[raptorheli2]

i know what you mean and i would have thought if it has a CE sticker then your fine but if your in doubt drop them a call and they will help i'm sure.....BUT, some people (and i mean people i did consider to be in the know) have said the first ones in were direct imports from usa and sold here legally in uk carried this sticker but the output was too high as no one noticed the way it was measured or something to be incorrect.

all you can do is contact horizon uk and take what they say as gospel i guess and thats good enough for me.

cheers

[moyesboy]

Just a bit more info - I took the back off my tx (A UK purchased DX7) to tighten uop the stick springs - they come set very soft. On the RF board ther was a big EU sticker, and another one on a big chip on the same board.

[ChrisB]

I also tensioned my sticks and noticed these stickers

[Rick Rotorhead]

Ok, so DX7s bought in UK are ok to use and don't invalidate insurence etc
American systems, including the gorgeous JR x9303 are too powerful to be legal here and using them will invalidate insurance and possibly therefore prevent use at UK clubs (well the ones that give a damn anyway).

The New JR will come out here, probably labled DSX9, but not for SIX LONG TERRIBLE MONTHS--AT THE VERY LEAST!!!!!! Damn and blast!

I am officially now VERY UNHAPPY and I blame Horizon totally for holding back the radio that I simply must have, whilst letting the yanks have it right now Grrrrrrrrrrrrrrrrrr. Funny than ain't it - exactly the same thing happens with new games consoles, games software, and other hitech electronic leisure gear - the yanks always get it first and we have to just wait it out knowing that the stuff is already outthere. With some DVDs for example, even if you have a US region coded player, the distributers won't sell you the American version of the game or film etc Its just plain nasty almost spiteful in fact...........

[SRH990]

I get ticked off too about the Americans getting them first but I think there are some fairly logical reasons: -

1. JR have had to licence the DSM2 technology from Spektrum which is owned by Horizon Hobby which is the US distributor for JR.

2. We will get a different TX from the US, they get fixed mode and anologue throttle trim, we get a model with the same features as the 9XII.

3. I'm pretty sure we get a very similar TX to the home market model made for Japan but 2.4ghz isn't legal in Japan so there's no rush for a 2.4ghz version of the UK/Euro/Autralasian model we will get.

4. The market in the US is huge, much bigger than all the other markets combined and money talks, it makes sense to get the US version on sale first.

I went with the Spektrum module for my 9XII and I'm very happy with it.

[ChrisB]

If you buy one from the US now,surely Horizon UK will tweak it for you,,they do seem quite helpful..
ALso i know someone who has imported a fair few DX7`s directly from a US supplier,i am supposing they will all be illegal over here

[moyesboy]

if there were to be an accident, and if the effect of your tx on someone elses model were thought to be a problem, and if they looked at your tx and tested it, and if it turned out to be over power, then it would have implications to the safe operation of that equipment at the higher power level in the USA.
What exactly are we worrying about?
Who is going to inspect your tx and tell you you can't use it? who in your club can tell where your tx came from and/or has test gear to identify its power level? (unless you have been boasting about your cheap grey import at the flying field, which is daft becuase I'm sure there are some model fliers working at the VAT office, and nobody is actually going to tell you they work there!).

The higher power level is in use and operating safely in the USA so there is no actual safety issue with the gear. The insurance can surely only back out if the tx power level is identified as a factor in the incident. Your car insurance still covers you if you have a brake light out and an under inflated tyre doesn't it?

The power level restriction is just a beaurocratic one, you might just slow a wireless network down if there is one near your flying field. You wont experience problems yourself, or with anyone elses 2.4Ghz model. Because if that was so they would be having problems in the USA.

[pchristy]

Just to confirm what Mark said earlier in this thread....

Mine is a very early UK DX-7, and the power output is 100mW (as near as I can measure).

ALL R/C equipment, be it 35 MHz, 459 MHz or 2.4 GHz is limited to 100mW erp (effective radiated power). The difference is that at 35 MHz, the aerials are very lossy, so you need to put the best part of 1 watt in, to get 100mW out! At 459 MHz and more especially 2.4 GHz, the aerials can actually have gain (the Spektrum antenna is rated as having 2dBi gain - that's an improvement of 2dB over a theoretical isotropic radiator).

I have a spectrum analyser that goes up to 20 GHz, so I can do direct side-by-side comparisons of 35 MHz and 2.4 GHz equipment. The Spektrum puts out exactly the same output on 2.4 GHz as my PCM9 does on 35 MHz - as near as I can measure. A Futaba 2.4 GHz set I checked also measured exactly the same.

So I can be pretty certain that my Spektrum complies with the rules.

Furthermore, if 100mW gives adequate range on 35 MHz (which we know it does), it will give *more* than adequate range on 2.4 GHz. (Because the receiver aerial is also much more efficient at 2.4 GHz).

Don't get caught up in a numbers game! Increased power levels will only run the batteries down quicker, and make swamping of the receiver at close range more likely! All you need is sufficient power for the job. Any more is likely to cause as many problems as it solves. 100mW is more than adequate!

I understand the reason that they allow a higher level in the USA is because there is *much* more activity on 2.4 GHz over there, which raises the background noise level quite substantially. This does not apply in the UK.

My understanding is that all *officially* imported equipment should be fine. It appears that there was a labelling problem with a small number of early sets sold in the US. They were incorrectly shown as meeting EU regulations. This is not a problem in the US, as EU regulations don't apply there, but would obviously be a problem if "grey imported" into the UK. I am told that this only affected a very small number of early US sets, so even if you did "grey import" one, the chances of you having a problem are statistically remote, and it sounds as if Horizon are offering a remedy for the small number of people who might be affected.

Oh, and for the record, it was Graupner in Germany that spotted the problem, not Robbe!

Cheers,

--
Pete

[Rod]

So, a UK spec tranny can only broadcast 2.5 miles instead of 5 miles, does that cover it? Having flown glitch, peg and model error free for some time, on 6100 receivers I'm wondering what the argument is? Also I'd like to say that the transmission protocol does not rely on power for it's effectiveness, it relys on timing and repetative messaging and at 2.4 gig you have plenty of time to do that. Also whats the alternative...........

[alfred]

So, a UK spec tranny can only broadcast 2.5 miles instead of 5 miles, does that cover it?

It doesn't work that way.
Let's assume that you RX maximum sensitivity is - 115dBm
It might have - 112dBm at 1.2km distance and -115dBm at 1.5km distance..the very edge at receiving.
So in a comparison, the UK version would reach 1.2km compared to the US version reaching 1.5km.
Both would be further away then you would ever fly.
But..
To get the extra 3dB gain and 0.3 km range, you would have to double the TX power.
So..very little gain in distance for having to double up the power.
That's why in real RF, example a link, it is better to let's say use a 9 element YAGI at as an example 25W TX power then a 6 element YAGI using 50W of power to achieve the same result.

[trebor27]

Just to confirm what Mark said earlier in this thread....

Furthermore, if 100mW gives adequate range on 35 MHz (which we know it does), it will give *more* than adequate range on 2.4 GHz. (Because the receiver aerial is also much more efficient at 2.4 GHz).

Have you factored in the energy absorption of the moisture in the air?

2.4G is license free because it can't be used for long range broadcasts due to the moisture in the air absorbing the RF energy. This limits the practical range of 2.4G (it's still long enough range for model aircraft it appears. Just don't try flying your heli in the rain! )

As humidity increases your range will change. How much so I don't know. But it definately will!

Ever wondered why your microwave oven uses 2.4G? Because water absorbs the RF energy, creating heat. When you broadcast enough energy on 2.4G you get enough heat to cook with....

Rob

[Rod]

You guys are so lame! I was flying yesterday in a downpour. The heli was responding great, that 2.4 gig message format is awsome. If I could only have seen what it was doing I could have recovered from that inverted pass!