RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

This references the FASST system for R/C cars, not the airplane version. Also, it does not explain the Futaba multiple antenna solution very well. It only mentions there is one internal and one external antenna.

Please realize that I"m not disputing your own reasons for using FASST over Spektrum. I'm willing to believe that in your area (France) the frequency environment may indeed be different than here for some reason favoring the Futaba system. I don't understand this, so I won't argue about that.

However, the original question was specifically addressing shielding issues that require physical annenna placement solutions to solve. The fact that Futaba uses a particular code, or switches frequency continually will not help. The physics of the problem define that any 2.4 GHz system uses a small wavelength (~5 inches) and when the wavelength of a signal becomes small compared to objects that may block the signal, shielding can result which diffraction cannot overcome. For our model uses, this is only a serious concern for large metal items like giant scale engines, batteries or exhaust systems made of metal or carbon.

Unfortunately, but understandably, neither Futaba nor Spektrum have devoted much advertising to educate us to what exactly what goes on under the hoods of their respective systems. Both use different proprietary schemes and these must be guarded to prohibit a third party from developing their own receivers which will be compatible with each system. But in the Spektrum solution, it is obvious that their engineers have developed a solution which does address the concerns of spatial positioning for maximum reception. Having multiple antennas which a user may position for his custom configuration is key to the Spektrum solution. I have not seen a FASST system explanation to refute the superiority of the Spektrum solution in this regard. Switching frequency (still within the allowable 2.4GHz band) will not alter the wavelength appreciably to eliminate shielding issues, because the wavelength will still be small compared to the source of sheilding. Only moving the antenna will help, or in the Spektrum case, having another antena which is not shieldied at a particular moment solves that particular problem.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Wind Junkie, I like your input and especially the engineer/pig signature signoff. I graduated with an engineering degree 39 years ago but never used it professionally as I ended up flying airplanes all my career. Another axiom I recall from engineering that I have found useful is "Never try to solve a problem you can eliminate." Additionally, it is always good to be able to "question" information that someone gives. The info may well not be supported by fact or evidence.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Thanks Airbusdrver. I'm a software monkey by day, but I learned EE stuff in school which I only use in my hobbies. Wierd how life takes those twists and turns, isn't it?

Very true on getting evidence for a problem. The scientific method demands repeatability. I guess in this case we need other French Spektrum users to speak up!

;)

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

I agree with our French friend that the FASST system appears to be a better system on the surface, at least to me. Frequency diversity provides much more interference protection than just switching back and forth between two preset frequencies whenever the voting circuit determines that one frequency has a stronger signal to noise ratio than the other frequency, although in many/most situations, it can work "well enough".

Presently, I own both the Futaba and the Spektrum systems and both have performed flawlessly and identically as far as the end result is concerned. I also own a set of third party modules, whose manufacturer's name I cannot remember at the moment, that work perfectly in my JR 8103 and 9303 Transmitters. I am very, very pleased with my 2.4 GHz spread spectrum gear. I fly all sizes of models with electric, glow, diesel and spark ignition engines.

With the potential for litigation very high, I doubt that either manufacturer would have released their products to the market had they known that their system suffered a serious deficiency.


Ed Cregger

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Ed Cregger I agree. I think in a few years the situation with the FASST and Spektrum/JR will be the same as it was with their 72Mhz systems. Everybody will have an opinion as to which is best, but in the end they will all perform equally as well. In other words, they will both get us up and down safely and most of the reasons we crash will not be associated with whether it uses two or a bunch of frequencies. It is all smoke and mirrors to most of us. I guess it is up to us not to let the smoke out. Because we all know that when the smoke escapes, it crashes.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Ed, with all due and sincere respect, I would contend that (in the case of Futaba) transmitters dropping unique ID codes and having receivers with antennas that cannot be separated with enough distance to prevent shielding are serious deficiencies.

I have been flying for a little more than 2 years and now own a fair amount of Futaba 72mhz gear and 9CAPS Tx. I am ready to move up to a "preminum" 12- or 14-channel system, but with the troubles at Futaba I am going to wait to see if Futaba can fix these issues and see what the consensus is on frequency hopping vs switching. But some way or another, it seems Futaba is going to have to adopt the idea of separate antennas to eliminate shielding. Imagine having a plane with a DA150 flying toward the TX with the receiver blocked.

But if I had to go one way or the other right now, I'd switch to JR.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

The problem is people trying to make technical evaluations that possess neither the RF background, nor enough manufacturer's information to arrive at a rational conclusion or make a rational decision. In fact, this problem is one that does not exist in the real world of flying R/C model aircraft. I hate to see everyone get all upset over nothing more than what we have been contending with since the original R/C models were flown by the Good brothers.

Futaba's "problem" is inconsequential and will be remedied easily, if it hasn't been already. I'm addressing the ID number issue. A software over sight.

Regarding blocking. If our receivers were only capable of receiving incident (direct) waves only from our transmitter, your concern would be valid. However, that is not how radio works in the real world.

Every piece of metal in the environment reflects some of the Tx's RF energy in nearly all directions. The chain link fence across the field, the power lines passing the field on power poles, the aluminum soda can lying in the ditch, the mailbox of our friendly resident neighbors, etc. All can reflect strong signals to the receiver that are strong enough to successfully control the model, if no other stronger signals were present. An engine, or pneumatic metal air cylinder between the engine and the Tx is really of no concern. It is something that folks with little to no RF training pick up on and worry about for no good reason. Even some engineers with an anal retentive bent will add extra outboard receiver modules, just in case. The higher the frequency of operation, the shorter the distances are between peaks and nulls. The latter translates into better control, not worse.

Our radio controlled models, regardless of frequency band or modulation techniques, are constantly flying through areas of strong signal peaks and then weak signal nulls all of the time as normal practice. It is a function of wavelength for the particular frequency. If this problem were so forbidding, none of us would be flying R/C controlled models at all. There is nothing magical about 2.4 GHz R/C systems.

I built, owned and flew a .15 powered pattern ship named Peppermint Pattie back in the late Seventies/early Eighties. It was faster than the piped Curare's and Blue Angels at our flying field. I guarantee you that if that model struck someone solidly in the head at full speed, it is highly unlikely that the struck person would survive. So much for model size mattering all that much when it comes to being lethally dangerous to humans in the area. We should be worrying about folks safety, not how much money we would lose if our model crashed. I am not implying that you are not properly concerned. I am saying that we, as a whole, should remember that occasionally our models do strike people and that we should do everything we can to avoid this from happening. I suspect that we are so successful in flying our craft that we tend to forget the real priority in our hobby - human safety.


Ed Cregger

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Guys take a look at this thread, you ' ll be surprised ? dont think so !!! I ' ll stick to DX7 rather than Futaba fasst.

http://www.runryder.com/helicopter/t172571p9

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Ed,

I'm seeing a new slant to your suggestion about not trying to fix a problem which you can eliminate.

Are you suggesting that by the FASST system switching frequencies, even if a particular frame is dropped because it came in on a frequency which was blocked for a particular location, it is likely that the next frame will not be blocked because the next frequency will be different enough that it will bounce around the blocking object? (we can assume the plane is stationary for sake of frequency switching rate involved, correct?).

The peaks and nulls you speak of are certainly be workable in the real world for most conventional installations, but I'm wondering how a single antenna can really deal with shielding in the most difficult environments. It's obvious that the FASST system works with big engines and metal/carbon objects nearby, but I consider myself one of many who is more than frustrated at Futaba's lack of an explanation of how they can ignore what spektrum has embraced regarding multiple antennas and reliable reception.

There are a lot of carbon glider flyers on RC groups right now trying to come up with a solution antenna wise to allow 2.4GHz systems to work in their expensive birds because the general consensus is that shielding is a huge problem. I lost control of a 3M Trinity for about 5 seconds last summer due to a bad installation with an AR7000. I re-routed the antenna, and it works better now, but it's obvious that shielding is reducing range. Glider guys don't want to expose their antennas for aerodynamic and durability reasons and this makes life a lot more difficult-- especially when you consider the airframe parts are small and thin.

I don't own a FASST system, but I'm wondering if would be worth getting one to try some range checks.
Joe

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

sir, sir!!! what kind of fuel is your small airplane uses? it is alcohol...
oh, i see, just like me... sir, sir, is it permitted to fly here?
well, bird does...
ah, ok... what is the range of your transmitter?


until now, i used to answer: to the eyesight, wich should be enough....

but now, i answer:::::




ORIGINAL: wind junkie

Ed,

I'm seeing a new slant to your suggestion about not trying to fix a problem which you can eliminate.

Are you suggesting that by the FASST system switching frequencies, even if a particular frame is dropped because it came in on a frequency which was blocked for a particular location, it is likely that the next frame will not be blocked because the next frequency will be different enough that it will bounce around the blocking object? (we can assume the plane is stationary for sake of frequency switching rate involved, correct?).

***Yes, but not with just the FASST system. All 2.4 GHz systems run at higher data rates (encoding) than our older systems on the lower frequencies, from the best I can tell with the manufacturer's data that is available.
***

The peaks and nulls you speak of are certainly be workable in the real world for most conventional installations, but I'm wondering how a single antenna can really deal with shielding in the most difficult environments. It's obvious that the FASST system works with big engines and metal/carbon objects nearby, but I consider myself one of many who is more than frustrated at Futaba's lack of an explanation of how they can ignore what spektrum has embraced regarding multiple antennas and reliable reception.

***Let me state right up front and outloud that I am not pro Futaba and anti Spektrum (I own and use both systems with no problems), in spite of how my comments may sound. I haven't "done the math" as yet, due to a lack of information. But, on the surface, I prefer the diversity of using more frequencies (FASST). In my mind, I see this as being more difficult to interfere with than choosing two random pairs of frequencies and bouncing between them at the voter's whim. However, the latter system, when employed with a separate receiver and antenna system has its advantages too. Statistics will most likely bear me out (in my slight favoring of the FASST system) if everything else is equal - but, truthfully, it seldom is. So, my opinion at this point is just a semi educated WAG.
***

There are a lot of carbon glider flyers on RC groups right now trying to come up with a solution antenna wise to allow 2.4GHz systems to work in their expensive birds because the general consensus is that shielding is a huge problem. I lost control of a 3M Trinity for about 5 seconds last summer due to a bad installation with an AR7000. I re-routed the antenna, and it works better now, but it's obvious that shielding is reducing range. Glider guys don't want to expose their antennas for aerodynamic and durability reasons and this makes life a lot more difficult-- especially when you consider the airframe parts are small and thin.

***I can't think of any radio control system that will function effectively if shielded by a conductive enclosure. On the other hand, I wonder if anyone has tried using the conductive enclosure as an antenna? Perhaps some conductive adhesive tape strung along the interior of the carbon fuselage, like the old timey tape stuff used on commercial building's windows for burglar alarms, might turn a problem into an asset?
***

I don't own a FASST system, but I'm wondering if would be worth getting one to try some range checks.

***I bought a Spektrum DX6 and DX7 a while back. Then I bought two of the Futaba least expensive FASST systems when they first became available. Eventually, I also bought the third party modules and receivers for my JR X-347, JR 8103 and JR 9303. Unfortunately, contrary to my usual behavior, I didn't keep records or notes of their usage. All have been successful so far and I now trust them - but with a cautious eye - like any other R/C system. Minimum ground range checks at manufacturer's specs are mandatory, but they are not the end-all of how the system will perform once airborne.
***

:D;)

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

A flight report on the JR 2.4 R921 receiver and flight update. This thread got a bit hijacked by Futaba/JR stuff, but the plane(remember that plane back at the beginning on page one?) has flown two uneventful flights. The advanced range check numbers from the Flight Logger and the normal 30 paces(actually 40) standard checks were good. So I suppose this thing works even when crammed into tight metal surrounded spaces.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

daggets

So far you HAVE convinced most of us that you have opinions but zip on understanding Spektrum's operation.
You would do well to follow your own advice and go to some other thread.
You do seem however to relish the "unwanted opinion" with no factual support.

Your geography is a 'little off' as well.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

? what does it means?

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

http://www.rcgroups.com/forums/showthread.php?t=830928

here you are...


onewasp.... peace

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

ford or chevy, chocolate or vanilla, earnhart or gordon, it does not matter, both systems work, different ways of course, I personally went with spektrum. Why? my lhs has had a Futaba 6 2.4 in thier case for a over a year, but they have sold dozens of spectrums, starting with the dx6, dx7 (heli and airplane), the new dx6i, and a couple of JR9303's. the flyers around here seem to favor the spektrum. Use what you feel comfortable with but dont bash people that dont use what you do. Happy Flying

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

?????????????????????????????????????????????????? ???????????????

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

---------------


I don't understand either, dagget. But that happens a lot with me, regardless of the topic or poster. <G>

We are all friends here, so just let it pass.


Ed Cregger

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

i m a bit disapointed, in classic pattern flying, we are between gentlemen, experienced, and it does no matter from where we are , the colour etc...
we have got a country for that...
there is no reason of making a war if someone can provide an experience and an opinion...

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

Some people seem to feel (I'm not pointing a finger at anyone in particular) that because we all use different products, we should not compare those products in the forum. Some consider mentioning factual criticisms as being rude, because someone elses feelings might be tread upon.

Other, more technical types of folks, who are used to objectively evaluating equipment, enjoy conversations pointing out the finer points of one brand's technology over another. Who is right? Technically, it is the folks that run the RCU website to determine which way the pendulum swings.

Me, I have all types of the 2.4 GHz radio systems available today. No, not every model they produce, but my inventory represents the manufacturers that I know of at the moment, even some third party manufacturers. All appear to be working as advertised.

Furthermore, I don't favor one brand over another and then consider all others inferior. In truth, the number one position depends upon the observer's needs and interests. But I see no reason that we should not be able to discuss the merits of one brand over another brand for certain needs. The problem arises when we consider that there are forums for this particular type of discussion and this one isn't it. My bad.


Ed Cregger

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

thanks ed... thats no big deal anyway... i have no glitches any more on my six month built curare, and thats the main thing...

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

------------


I didn't see anything but speculation by typical end-users. Did I miss something?

Furthermore, I see absolutely no information that spoke badly of Futaba's FASST system. Just some folks speculating about encoder latency, etc. All systems, even JR/Spektrum, has encoder latency. Whether it is an issue or not is another matter, but there is nothing about the Futaba FASST system that puts it at a disadvantage versus the other systems.

I own Spektrum and Futaba systems, plus a third party set of modules for their handling of the 2.4 GHz band. All are different, but all work well.

If you want to hate Futaba and love JR/Spektrum, that is just fine with me. But, understand that I see no basis in fact for this preference.


Ed Cregger

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

I’m not sure how Futaba will ever be able to completely fix the firmware problem in all the systems they sold that resets the ID. Sure, people on RCU know about the problem and know the radios need to be fixed ASAP, but we make up only a tiny, tiny segment of the RC community. I bought up the issue at our last club meeting and NO ONE at the meeting knew about the ID problem including two guys using the equipment in question! If Futaba does not track down every single system they sold and fix them the potential for a bad accident will exist for decades.

Inherent in the spread spectrum concept is the security that someone else will not interfere with your radio operation. Futaba violated that core concept. It is more than someone getting shot down and losing a valuable aircraft (that would be bad) but is the potential for a serious accident that concerns me.

Yes, any radio manufacturer can make a mistake but what counts is what they do about it. I’ve been a Futaba fan for a few years and like their equipment very much but in this case from what I’ve seen so far Futaba has handled this problem extremely poorly. They need to be responsible for the mistake and aggressively track down the owners of the equipment in question and fix it.

RE: HAVE YOU CONVERTED PIPED PATTERN PLANE TO SPEKTRUM/JR?????
 

We agree on what Futaba should do. Let's see if they make the proper decision.

I'm argueing with some folks (friendly style) about the type of channel hopping SS that Futaba utilizes. This has nothing to do with the present ID debacle.


Ed Cregger