Futaba 10C from JR eyes...

[electricsceadu]

forbsy you're not the only one still on 35mhz
the more that go onto 2.4ghz means the more spare channels we have to play with

[jiberjaber]

Oh dear, oh dear, oh dear. Here comes the bombshell. If you can hang on for a while here is the next version of the 10C. Known as the T10CG. Sold as a combo with the 8 channel rx and battery packs.

http://www.e-heli-shop.de/

Do a search for T10CG

I did - 547 Euros (about 490 UKP) for the 10C plus a receiver, I paid 339 and 100 odd (608 receiver) for the same, so not much difference in it

forbsy you're not the only one still on 35mhz
the more that go onto 2.4ghz means the more spare channels we have to play with

Well after having two conversations with chaps at my club (amitidly the were fixed wing.)

One wanted to fly his glider but didnt want to walk back to the power square to put his card on the peg board, the other turned up and wanted to run up his new model (engine) in with TX without walking down to the power square to put his card up....

With characters like that around - and I suspect there are more at it... -

35MHz you can keep it, I know how much it costs to crash, best of luck with it ! LOL

[electricsceadu]

the tx control we have at our club is
1 a named peg on
2 every one on 35mhz is on a different channel as given out by the club's commitee
and membership is limited to 30 due to the size of our flying site
3 a frequencey scanner is in operation at all time

4 if any t**t turns on the same channel as me they will need the nhs to leave the field

[barney]

Forbsy the DX7 is just the JR2720 with inbuilt SpeKtrum and some software changes.

I've personally had two confirmed shootdowns...one puttimg me out of the hobby for 5 years..(It used to be a very expensive pursuit 30 years ago). Witnessed maybe 4 others going down. Possibly another half dozen + recovered before impact.

It happened a lot more frequently than you imagine. It's not just the channel your on but you also had to be aware of X-channel intereference 23 channels apart if using Non dual Conversion Rx's.

I've even caught people using the wrong peg blissfully unaware they were on the wrong frequency. We had 27AM then 27 FM and CB Radio the 35mhz 20 ch which was later extended (hence the x-channel problem).

Another one I've seen that seems to be OK now on 2.4 is Swamping (Where a pilot has been between you and your model..)

Electrisceadu.
Electricial interference is all but gone on 2.4 so its not just purely a benifit of having a free frequiency.

[SimonV6]

Oh dear, oh dear, oh dear. Here comes the bombshell. If you can hang on for a while here is the next version of the 10C. Known as the T10CG. Sold as a combo with the 8 channel rx and battery packs.

http://www.e-heli-shop.de/

Do a search for T10CG

its just the 10c with an antenna mod so why such a "Bombshell"?


which anyone can do if they so wish?



Simon

[electricsceadu]

i may have been lucky only ever seeing 1 t**t turn on the same 35mhz channel,(i left the club due to no disapline over this)

but i've seen quite a few 2.4ghz power lock out/brown out or call them what ever you wish

plus as i fly futaba i don't like the crap arial position of the 10c and why should i have to mod it? the 6ch set has it in the correct position

the 10c should be sold as a 35mhz set or a 2.4ghz set not a module shoved in the back of a 35mhz set (i can do that with my own 35mhz set)

why i haven't changed over
never had a problem with 35mhz
too much cost to replace my rx's (i have a large collection of vintage and scale helis, plus the pod and boom i have)
and then if i did i would need to upgrade the rx power to stop brown outs (or the possibility or them)
i don't like the arial position on the 2.4ghz modules for my tx (and the 10c)

don't get me wrong i'm not against 2.4ghz
any new comer to my club i advise them to go with it due to the benifits of 2.4

if i was to go 2.4 at the present time i would have a the 9ch jr (and i've never owned a jr radio before)

[barney]

crap arial position of the 10c and why should i have to mod it?

No longer the case as there is a dedicated 10 2.4 just being released as we speak. But that immeadeatly tie's you to 2.4.

i can do that with my own 35mhz set

Yes you can..but you miss out on some of the benifits that DSM2 brought with it.


If your 35Mhz does it for you thats fine..I would stay with it myself if it still satisfied my own criteria.

Things move on and electronic advances make for a safer enviroment overall so when its 'time' to move on I chose to take advantage of the extra refinement it offers.

BTW I still have a futaba 'M' series 27Am on 'Blue'

[pchristy]

I've come to this thread rather late, but I'm pleased to see that my lad's contributions have been constructive and well received!

Many of you will be aware that my profession is in electronics, though I must confess that some of the more esoteric functions of 2.4 GHz make me feel I'm struggling to keep up! Nonetheless, there are some points worth considering that are generally overlooked.....

Firstly CE marking and its validity: There is nothing to stop anyone declaring anything to be CE approved. However, if you are going to do this, you'd better have some evidence to back your claims up should they be challenged.

In the case of the aerial mod Mark has described, yes, technically it *may* invalidate the original testing. However, since no changes have been made to either the electronics or screening, it is highly unlikely to have adversely affected anything. Furthermore, since I've got a spectrum analyzer that goes well beyond 2.4 GHz, I can easily check whether anything has changed or not! That's not to say I can do a full CE compliance test - I can't - but I can tell if there have been any adverse effects! This should make "self-certification" reasonably safe. (Note: Don't attempt any mods to radio gear unless you are really confident you know what you are doing! It will also invalidate the guarantee!)

Moving on to the 1024/2048 question, this again is a matter of understanding what these numbers really mean.....

A resolution of 1024 means that the system can resolve one part in 1024, or just better than 0.1%! Now I don't know of any helicopter that has a linkage that accurate! Come to that, I can't think of a servo that can manage much better than 0.5% - especially after a season's hard use!

Further, in 35 MHz terms, because of the narrow channel spacing, there is a limit to how much information you can send over a channel. If you need to send more, then it must be done more slowly. A 10-bit PCM system transmits over 10 times as much information as a PPM system, which is why PCM systems are always more laggy than PPM. They simply cannot achieve the same frame rate in the limited bandwidth. There is a certain amount of "creative accounting" you can do to improve the situation, but at the end of the day, you cannot change the laws of physics!

2.4 GHz systems have over 10 times the bandwidth available compared to 35 MHz, which is why Spread Spectrum radios appear more lively. They are not bound by the same constraints. However, the point about resolution remains - there is no point in building a system with 0.1% resolution if the even the best servos struggle to get within 0.5%!

But that is not quite the end of the argument! Resolution errors are additive, and this shows up when you introduce mixing. If I mix three signals together and each has a resolution of 0.1%, then the resulting signal will only have a resolution of 0.3% (0.1 x 3). So there IS a case for using high resolution internally in the transmitter, so that the end result still falls within a reasonable resolution.

But I maintain there is absolutely no point whatsoever in TRANSMITTING that level of resolution. It is a complete waste of bandwidth as you will never be able to buy a servo capable of that level of accuracy, nor will you be able to make a linkage that accurate! And there are better things for which the bandwidth could be used!

Cheers,

--
Pete

[Ashley Davis]

interesting, so frame rate is where the gains are but resolution isn't as important.

Based on that I'm more than happy with my recent cheap upgrade to a DX7 SE. Which although it is also 2048 it has the fastest frame rate of any radio currently available.

[simon_t]

Firstly CE marking and its validity: There is nothing to stop anyone declaring anything to be CE approved. However, if you are going to do this, you'd better have some evidence to back your claims up should they be challenged.

In the case of the aerial mod Mark has described, yes, technically it *may* invalidate the original testing. However, since no changes have been made to either the electronics or screening, it is highly unlikely to have adversely affected anything. Furthermore, since I've got a spectrum analyzer that goes well beyond 2.4 GHz, I can easily check whether anything has changed or not! That's not to say I can do a full CE compliance test - I can't - but I can tell if there have been any adverse effects! This should make "self-certification" reasonably safe. (Note: Don't attempt any mods to radio gear unless you are really confident you know what you are doing! It will also invalidate the guarantee!)


Cheers,

--
Pete

Mark/Pete - Have you seen page 4 in the latest BMFA News? As a National/International competition flyer especially, I would not want any degree of uncertainty over the legality and/or insurance coverage for my equipment. Even worse, the consequences of loss of insurance cover in the event of a serious/fatal injury are too grim to contemplate. (neglecting the effects of injury itself). I guess it comes down to how confident you feel that you can convince any investigating authority that you have supplementary evidence (asssuming they will accept that) if such a theoretical accident case were to occur. I know that in fatal model accidents that the investigation was very thorough.

Simon (wishing that as a radio ham we had the same rights as the US to mod radio gear...)

[SimonV6]

As requested.. pictures of my 10C now as an integrated system.

I did get Trevor to send me a standard Futaba module case that I was going to modify.. but the 10C digital connections for the 2.4ghz connection meant that it wasn't to be.. so a dremel was taken to the stock 10C module case to remove the aerial.. and a Solid G sticker applied to cover the hole that was left!

BMFA now saying these mods are illegal? (AS ABOVE POST) does anyone know if thats true?

I was thinking of doing the antenna mod on my 10c?


Simon

[Andy from Sandy]

There is a press release in the latest MHW:

Recently it has been noted that a DIY transmitter modification has been the subject of discussion on some of the online model flying forums. The particular unit in this case was the Futaba Field Force 9 used in conjunction with a Spectrum 2.4GHz module. The modification referred to involves drilling a hole in the transmitter case and re-routing the co-axial cable inside the case and out into the existing 35MHz aerial mounting. Anyone contemplating this particular modification or indeed anything similar should be aware that this would immediately invalidate the CE marking as well as compliance with the relevant ETSI standard.This would render the equipment 'non compliant' with UK legislation and thus potentially illegal to use.

Think very carefully before you make alterations to equipment of this nature (this is particularly the case with transmitting equipmentas it will always have to comply with the UK standards laid down by Ofcom.)

It should be remembered that if you do modify equipment of this nature then you are personally taking on the responsibility for its compliance and legality.

Manny Williamson, Development Officer, BMFA

Notice how the guy says "potentialy illegal". Reading this the BMFA seem to only be giving a warning. It would appear they are not fully clear of the implications of modding a TX in this way.