Moving to 2.4Ghz....

[Fred]

Oh, on a side note, I did not noticed to be more "in touch" with the glider...
The t8z is 1024, and to be honest, no differences at all.
We'll see with tha Alpina next.

[IceWind]

Fred,

T8Z? Futaba?
Most futaba if not all only do 1024 or 2048 (new ones) when using PCM on PPM they do 512
and only use only 8 chn. So if you're using the corona module you'd need to be in PPM and stuck in 512.
Could be this why you didn't noticed any difference?

Keith,

I particularly enjoyed the tests regarding using 1 or 2 antennas. There was much fuss going around because one of the antennas in the Assan modules are connecting to ground, and on the micro rx's they have only one. So the assumption was that the second one was there only for decoration or to look like the Spektrum modules.
If those tests are correct they indeed seem to help on the noise filtering.
If you like those articles I can get you tons. In Portugal the 2.4Ghz usage is still not very well defined and for quite some the discussions ended in collecting loads of information about the several systems offered.

[Happy Days]

I doubt that the “extra” antenna is for decoration purposes Nando. Most antennas have a “grounded” side.  The grounded part improves the reception of the whole antenna system.
I imagine the rx with only one antenna wire is for short range, possibly indoor , use only.

It’s been many years since I studies matters such as the Law of Antenna Reciprocality, and the inverse square law of power over distance. :roll:  God, doesn’t that sound sooooooo boring! I’m not sure if knowing all the above makes me a Geek, or a Nerd. :oops:  What do you think?

K.

[Fred]

Hey Fernando,

For the resolution of the Ct8Z module (sorry, missed the C in the module name!  :oops: ), according to Corona, and a few guys on RCGroups, this is a 1024 system (Same for all the DSSS stuff it seems  :?: ), but I have to admit that I don't have a clue, I'm just a basic user of that stuff :?

Keith ---> You're a geek !  

[IceWind]

Keith,

I admit I had no opinion on that. For me radio frequencies and related matters is a strange world, don't fit in my limited electronics knowledge.
But I was smart  enough not to cut the extra wire. :-)
+1 for Geek.

Fred,

Well the idea that i had was that ti depends on the radio, receiver and servos.
They have to be able to work with the 10bits resolution to get the 1024 steps resolution, but I'll check that out.

I leave here another link in case you guys don't know it.
http://www.rcmodelreviews.com/corona_dsssv2.shtml
This is a review to the Corona system.
This guy performed the sames tests to other brands as well and have some really nice videos on youtube about the tests.

[Fred]

Just back from the slope, testing my new 2.4ghz system with the good old EasyGlider  

After I sold my Corona system, started to look for a new one... Didn't had to look far as I already saw the system made by FrSky and was impressed (and so a lot of other people!) with the specs of their product.

2.4ghz system, ACCST (like FASST), and cherry on the cake, telemetry!
All that for about 50 euros  

So, played with it for a little while, and today, made the first flight.
There is a range check function, and in low power, had about 40 mtr range (that's a bit more of 2 miles range at full power in theory).
As expected, like the Corona system really, no problem at all! Did not manage to fault the system whatever I tried!

Telemetry now... You have a range alarm, and a RX battery voltage by default. The good thing, is that the telemetry protocole is open source! Lots of stuff is being made, like a vario etc etc, and all that at ridiculous prices!  
Failsafe is dead simple to program on the RX (set the controls like you want them for the fail safe, press a button... and done!)

I m waiting my 5dbi aerial for the TX, that should extend the range to 7+ miles (tested by a few guys on RCGroups ).... Don't need it, but will feel safer (peace of mind).
They are going to release  a "box", like the Jeti box soon, with a few captors (vario etc)... Looking forward to that!

Anyway, you guessed it, I'm pleased with the system, cheap, secure, full of functions like bigger expensive brands (or even better for some...).

Next glider, the Alpina !

[Happy Days]

So, Mon Ami, you’ve entered the world of modern radio communication (2.4Ghz.) :clap:

Haven’t heard of ACCST. (Another type of channel hopping I presume) Each rx has to be linked to the tx, does it? At least you’ll have no fear of another flyer shooting down your precious Alpina.

I have to say I’m a little sceptical about telemetry. I can’t really see that it satisfies a need or offers an advantage to the pilot. :?:  (Other than curiosity.)

I mean,………Dual Rates? Yes I can see the advantage of those.
Exponential?…….I can see the advantage of that as well.
Being able to mix control surface movements together?…………Yes.
All these things can, if the pilot wants to, be used to improve, or make easier the skill of flying. But Telemetry?

Don’t get me wrong, I’m not saying it’s a bad thing. But I just get the feeling that Telemetry is gimmick  that the salesmen have come up with to try to convince us that it’s the latest ‘Must Have’ gadget.

What do you think of it Fred?

Keith

[Fred]

Hey Keith,

Yeah, that's like FASST, with diversity (the 2 aerials are active).
Never had a problem in 41 or 35Mhz, so that's a bit weird to me to move to something else knowing I never had any issues... But for the sake of safety, flying machines over 12 ~ 15Kgs, keep thinking that one less parameter to worry about (being shot down) might worth the hassle.

For the telemetry now, I think this is one more safe point to take on board. Knowing your battery voltage at all time in flight, is definitively a plus (even if I never had problems with batteries ! Part of the "job" to keep them healthty and check them before flying if you know what I mean).
Range... Well, that's default, so why not.
After that, I might get into a Vario thingy, but really don't feel the need, especially in Slope Soaring, that kind of remove the fun on thermal days!  

So, to me, telemetry, yes, but not abusing it (voltage alarm, and that's pretty much it), I want to fly my plane, not spend my time playing video games!

And I never use Dual Rates  

[Ron]

Hi Fred and All,

This 2.4GHz thing is interesting.
We all know (don't we?) that the 2.4GHz band was not intended for controlling models, but why not do it if it's possible?
There's lots of 2.4GHz activity around here. Even my broadband arrives by 2.4GHz link from Mt. Gabriel. That's about 9.4km away, but it needs special antennas both ends.
And the BB provider (Digital Forge) uses 2.4GHz for their back-links to connect to other of their base stations as well.
And of course nearly everyone has a home wireless network that uses 2.4GHz.
None of these used diversity as far as I know, as there are specific RF channels.

And having worked for a short while on frequency hopping systems for the UK MOD, they are surprisingly tolerant of interference.

You can still, of course, still suffer from saturation of a receiver input stages by a strong nearby TX signal, but that shouldn't be a problem when the RX is in a model aircraft.

But like you Fred, I have never suffered from any problems with 35MHz.
So should I change too? :?

Telemetry.
Now I can see a use for that.
Battery voltage definitely, especially if it could show minimum voltage during servo movement (highest current).
Vario?
Altimeter?
Well, full size glider pilots use them and they should be able to fly 'by the seat of their pants' unlike us poor earth-bound souls.
So yes, I would go for a vario and an altimeter.
And something that could be interesting is airspeed.
Where is the stall point?
When you are 'flying backwards' in a strong breeze, just how much slower can you go without falling out of the sky?

But first I have to just get the EG up in the air  :oops:

[Aidan]

Telemetry definitely has it's uses.

I just started using the Jeti system a short while ago. The standard functions on all the JETI 2.4GHz receivers are RX voltage and signal strength for each antenna. It's great to know the voltage of your RX battery and know you'll get a warning well before you ever fully discharge it. Don't know about the rest of you but I probably never drained an RX pack below 50% just in case (so all my packs were heavier than necessary or I got less flying time than I could have). I can see the signal strength function being useful too although I haven't made much use of it yet. For example it'll give you some warning if you're flying in a very "noisy" area where you wouldn't otherwise know there was a risk. It should be possible to use this as a lost model finder as well! :wink:

Probably the biggest advantage of telemetry for me will be measuring battery usage for electric planes. This needs a separate sensor so I won't be using it on my indoor planes for example but for larger stuff it's very useful to be able to monitor pack voltage, current draw and capacity used while in the air. Instead of timing the flight and guessing if you've used more or less throttle than usual you have a fuel gauge and you can put an alarm on it if you like.

So for example I put a current/voltage/capacity sensor in my electric glider. It's got an 800mAh pack in it powering the motor and radio. After flying a few climbs to altitude and some thermalling I wouldn't have much idea what was left in the cells so if I was to catch a thermal I'd be wondering if I had the power left to spend an hour circling in it. But now, with telemetry set to alarm after I've used 600mAh, I have absolutely nothing to worry about until the alarm goes off telling me I need to start thinking about coming down.

The telemetry doesn't get in the way of normal flying. The information is there if you need it but there's no need to even think about it the rest of the time.

Aidan

[Fred]

Hi Aidan,

I agree, the only thing, as usual that I see wrong in all those "aids", is the abuse of them.
In Retroplane, we sometimes see people flying gliders, in gale force winds and massive lifts... Using a vario... Come on! do you really need that?
Anyway, I'm a bad example, I don't use any mixage (just expo), flight phases etc.. I fly the glider, not the radio!

Mini pointless rant over  

Just sometimes, I wonder how we managed to fly RC planes in the old days (here we go again...) without all these gizmos!    Not that I'm against progress etc, but sometimes, just wondering. My first 4m glider, I only had a 4ch radio... Only servos reverse (that was a big thing to have at the time!).
 

And back to the subject, tested my 5Dbi antenna, and I can already see a great range improvement! Need to be tested on the field now, but even if that's useless, a few miles more range (7 miles in theory...) makes me feel a bit safer!

[Ron]

Now Fred, don't start me on 'the old times'.
What about single pulse 27MHz radio and escapement rudder only?

Ron

[Fred]

Ah 27mhz, that was fun !    Really had to learn how to fix your planes in those days!  

Never had the rubber band servos! My first servos were the in-line ones.

Still remember my first "mini" servo... The size of today's big standard servo, but at the time, that was cutting edge technology! And not cheap!

[Happy Days]

ZZZZZzzzzzzzzzz....................OH! Have we stopped reminiscing now? :lol:

Actually this discussion has thrown up a couple of ideas that I hadn’t thought of.

I hadn’t paid much credit on being able to know a model’s rx/servo battery voltage in flight, having never had a problem with such things myself.
But then I’ve never had the “need” of a seat belt in my car, but I still wear one,……..Just in case.

Personally I wouldn’t have much use for varios’ or altimeters, but Aidan’s idea of the voltage reading of flight batteries would definately get a thumbs up from me. (For my powered planes) I can certainly see the benefit of that. :?:

(It’s always good to  hear other peoples point of view.)

Keith

[Ron]

You're right Keith.
But.... I call them, or think of those times, as the 'bad old days'.
It's a bit like old cars.
We used to think they were great, but try driving one now and you'd soon enough jump back into your modern warm, dry, fully syncromesh, five geared, overhead cam, etc. etc. modern car.

So give me all the modern radio facilities that 'just work'.

Whether I actually need them or not is another matter. :?
I think maybe I do, but only if I don't have to pay more for them. :?:
(Well I did have a Scots Grandmother :wink: )

Ron