RC India

Have you had a personal bad experience with 2.4Ghz radio systems, that has really been traced back to the radio system itself ? 

It seems like some people (at least a minority) seem to be skeptical with about 2.4 radio technology, even when its adoption is becoming wide-spread.  In the US, it seems like there is 75% or more adoption of this technology, and the rest 25% or so is waiting mostly because of the money involved in spending on a new radio and changing existing receivers.

The only case I personally know is that of a competition pylon race enthusiast who uses full carbon fiber race planes, and he went back to 72Mhz after he lost control two times.  He believed earnestly that 2.4Ghz had something to do with the loss of control.

Do you personally know of someone who had issues because of 2.4Ghz radio technology, and thus went back to 72/35/40Mhz ?

Hey Anwar,

Carbon Fiber attenuates 2.4Ghz signals.  So even when setting up our normal planes, we are advised to keep the Rx as far away as possible from all Carbon Fiber parts / rods!  When 2.4 Rx is used in a full carbon fiber plane, proper care should be taken to keep the Rx antenna outside.  Even then it poses a threat.  So 2.4 systems are a big NO NO for Carbon Fiber planes!

I have been using 2.4 Spektrum as well as Futaba for quite some time and I have not had a single glitch (except once when my Rx battery voltage went very low..my mistake though! it was just a 2 sec loss of control.  no crash / damage!).

I had personally seen a 2.4 Ghz Futaba controlled trainer plane go down after total loss of control for about 5 to 10 seconds.  They were flying regular circuits when all of  sudden there was loss of control and plane spiralled down into the water (Yes WATER!!).  But later on we found out the reason for the crash to be low battery voltage again! the Rx pack voltage had dropped below the threshold and the Tx / Rx connection had reset! 

My advice would be to use a Lipoly with a regulator if you have to go for 2.4 Ghz systems!  But people have been using NiCd packs also.  Only thing is, make sure that the battery voltage is high enough as 2.4 systems consume more power!

Most of the crashes attributed to 2.4 systems is becuase of low voltage cutoffs! Whenever the voltage drops, then the connection is reset and then 2.4 systems are blamed to be faulty. 

People should take enough care to keep the Rx pack voltage high enough (higher than required for FM systems) and also to keep it away from Carbon Fibers!

My 2 cents!! Comments / Corrections welcome!

Regards,
Chan

Yes Chan, most of the crashes are due to people not monitoring their receiver power levels. That is why I mentioned "problems due to the system itself". 

Pretty much everyone I know is on 2.4Ghz now, and I myself converted to 2.4 in December 2008.  No issues at all, so far.

I still wonder why some people are holding out for what seems to be no logical reason.  Now a days, it seems that you are more likely to crash due to a frequency conflict with 73/35/40Mhz, than an issue with 2.4Ghz.

Hi Anwar,

Exactly what I was trying to imply.  Most conventional people are happy with their FM radios and are familiar with them.  So a change at this point of time is unwanted for them.

And going by a few negative reviews, some people are still holding out.

The popularity of 2.4 Ghz is so much that the majority of the aeromodellers have been migrating and there are bound to be a few accidents here and there due to defective manufacturing.  This cannot be attributed to the technology.

Take the DX6i notification issued recently.  Many of the Txs were recalled as they had defective potentiometers.  If anyone who has migrated to 2.4 recently has a crash because of this, it is automatically blamed on the technology rather on the defective Tx.

Even in our field, die hard FM aeromodellers are slowly changing over to 2.4 because there are many interferences and there have also been a few crashes because of this and the only way out is the 2.4 way!!!

I would always recommend 2.4 tech to a responsible aeromodeller who takes precautions to setup everything correctly.  As you move on to advanced technology, the responsibility also increases.  That alone should be kept in mind!

Chan

All the issues I have heard are due to manufacturing defects (which could happen to 72MHz as well) or improper usage or installation. The spread spectrum modulation used with 2.4 makes it much more interference immune compared to PPM/PCM. You do need to be a little careful about the small antenna getting shielded by metal and carbon fiber parts. But it is not so bad, so many people are flying helis with carbon fiber frames without any issues.

Hi Guys ,
I think 2.4 G is great and surely the future of Aero Modeling , but what is also holding back many like me is the cost of the receivers .
Chan for eg the Radio itself with the receiver cost you around Rs 10 K but each subsequent receiver costs you around Rs 4.5 K right  that is 1/2 the price of the system in the 1st place .
If  you a flying a few models it is OK but  if I have many models or am an electric scratch build enthusiast then I cannot afford to add a Rs 4500 receiver on a Rs 400 scratchbuild. Imagine my investment if I was to have 6-7 flying models just in terms of receivers especially so if I already have conventional receivers on many of my models already.
 The advantage of the conventional system is off the shelf receivers are available from various manufacturers at very very economical .

As far as freq, interference is concerned I think the Corona synthesised 72 or 40 or 35 Mhz receivers due to their narrow band width  largely takes care of the interference factor .The other advantage if these receivers is that you can use the same receiver with either JR of Futaba as they are Auto Shift , further they have a 1 mile range . I have used one of thees receiver  on both my JR and Futaba and they work great .

In my opinion the best route to 2.4 G is to go in for a Module based conventional transmitter  and the buy a  Corona  Module suitable for the make eg for Futaba / JR . Once this is done then the cost of receivers subsequently is 1/2 the price of the original ones .This would be the Ideal route .

In fact on RC groups I have seen some posts of guys having converted 6 exa's and similar  transmitters with 2.4 G corona Modules , dont know how  but I guess these modules were external .


Sai

The spectrum recievers are around $50 (Rs2400).  That is one big reason Spektrum is so widely being adopted.  In fact it is almost becoming the de-facto standard in the US/Europe.

Yes Anwar But $50 does not mean Rs 2500 when you sell them in India you have to pay 35% Duty and clearance charges by the time a seller gets it into India. The Corona 2.4 G receiver is exactly 1/2 the price  ;D.
So I would rather invest in a corona module once and have my future receivers at 1/2 the price of a spectrum

Yes, I keep forgetting about the customs cost in India  :'( 

Yes.  I also agree with the cost factor.  To be exact, I paid 4500 for my Rx (AR6200) and i cant afford to keep buying Rxs for all my planes. 

But if people can afford to get 2.4 systems and are looking for high end technology, then they should not worry about the cost factor.

Corona is also very very good and a nice solution to the Rx problem.  but still, brand conscious flyers might prefer Spektrum or Futaba.

Futaba 2.4 Rx are about 5k and Spektrum is about 4.5k.

The $50 Spektrum Rx are not full range ones.  The least price i was able to find for a full range 6 ch Rx (AR6200) was $79.

And moreover if I have to go in for a module based Tx, i would again be paying a heavy amount and in addition to it, there is the module cost and the Rx cost.

In general, anyone looking to get into 2.4 Ghz can look at getting a module based Tx if their budget permits. 

But to all of us folks who already have non-module based Tx like the Futaba 2.4 6EX or the Spektrum DX6i, we have no option other than to go in for these expensive Rxs.

But end of the day, I am able to fly without any hassles and worries about interferences / glitches and radio probs.  That has made it worth my money.

I am actually considering getting a module based Tx as well sometime in future!!  Then, it would be Corona for me. 

Would be following this thread closely to see whether there have been any accidents due to 2.4 (touchwood)!!

Chan

The synthesized receivers (Corona or others) are still susceptible to frequency clashes.  They just allow you to switch from one frequency to another, but somebody will be shot down if two people are on the same channel. 

If one is looking for peace of mind as the end result, it looks like 2.4 is the way to go.

Yes you are right about frequency clash , but hey guys dont forget that these systems have been around for long  and people have got used to checking frequencies before turning on their transmitters thru shear habit .
The advantage of the synth receivers is they operate on a narrow band from the tuned freq.

I for one am not going to shift to 2.4 g in a hurry mainly due to :
1) cost of receivers : I have around 8-10 models in hand with receivers hence cannot afford to junk all of them and replace them especially considering most of them are low cost scratch built .So the plane really is not a major issue as far as I am concerned .
2) Experience on getting Shot down on freq. clash  : in my 5 years at the field have seen that happen just once
Have seen aircraft flying 2.4 G crash due to lost linkage more often than crash due to freq. clash . The reason for the lost linkage may be anything and explainable but the crashes due to 2.4 g out number the crashes due to freq. in my experience .
Anwar the way you have put it is that freq. clash is something that happens on a daily basis at all air field that is not right as per my experience 99.9999999999999999999999 % aero modelers are responsible to ensure against it , In fact as I saw it at IIT Mumbai the organisers managed 62 participants x 2 flights each  and their  transmitters very well without a
single freq. clash. Give it a break  the freq. based transmitters have been around for far too long to be written off in such a hurry.
sai

Hello Sai -  I only shifted to 2.4 recently, and was quite happy on crystals earlier  ;D  My module based radio (Futaba 12FG) can handle both and even now I fly my foam planes on 72. 

In my close to 2 years of RC, I have seen 4 planes/helis being brought down due to frequency clashes, and heard of one guy having issues with 2.4 and his full-carbon-fibre-body plane. I guess it is all a matter of self-discipline from the part of the fliers.

I guess my point is that with 72/35/40 you are at the mercy of others, which is something no one appreciates   8-)  No one wants to feel vulnerable !

My point is that if people are staying away from 2.4 these days, the only logical reason should be cost.

Hi Anwar,

I was not referring to the Corona synthesized receviers.  I was referring to the Corona 2.4 Ghz Module and Rx available with Mr. Sai.  I have seen the module and the fit into Futabas are perfect.  I even checked out a few reviews. 

Corona also manufactures 2.4 stuff in addition to its synthesized receivers!!

Regards,
Chan

Hi Chan - Sai mentioned "synthesized", so I was under the impression he was talking about 72.  And the only Corona product on the store was a synthesized reciever from Corona. 

http://cgi.ebay.in/Corona-Synthesized-Dual-Conv-Receiver-8Ch-72-Mhz_W0QQitemZ150310303296QQihZ005QQcategoryZ2563QQcmdZViewItem

Hopefully the 2.4 version will be back in stock again soon  :)

Yes, the only draw back of the 2.4 is the COST. getting a Rx and 5 servos is the DEAL, and you must use only DSM2 Rx, so compatibility is yet another but small issue. IMO!
But when it comes to use and interface, I think the technology is a break tru.
I'm a beginner and haven't yet got the full spectrum of Spektrum  :) I love my Radio and Know that its a good piece, yet last week when I got a new plane, I realized that every time I add a model I'll have to add Rs7500 - 8000 to it.  :-\ (dsm2 Rx, Batt and Servos) well the Batt and the servos apply in any case.

I know some people who use velcro to attach their receivers to their aircraft, so that they can just move it between planes, keeping costs low. 

Just need to label the servo and other connections.  Takes couple of minutes  ;)  {:)}

Well, I do not fly 2.4GHz just because I am happy with my 72MHz stuff and do not want to re-invest in another radio.

BTW, I have checked out the corona 72MHz synth receiver and it works like a charm!!.. Man!!.. That thing could receive the signal from a (closed antenna) TX kept 500m away. No glitches whatsoever... In fact, I could not find the max operating distance as the receiver keeps working no matter how far I move away from it... No wonder, I got fed up with the range check and returned back.. If I am going to buy another 72MHz receiver it would definitely be a Corona.

-Ismail

That is a very strong endorsement for Corona receivers  :)   Looks like Sai picked the right bits to carry in his store !

I will pass this information on to others who are going to buy 72Mhz receivers. 

Corona Receiver are also available with us the links are given below

Corona Synthesized Receiver RP4S1 72Mhz
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=89&products_id=238

Corona Synthesized Receiver RP6S1 72Mhz
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=89&products_id=239

Corona Synthesized Receiver RP6D1 72Mhz
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=89&products_id=240

The Airtronics/Sanwa Radios Receivers Servos are now available in India for Both Air & Surface

The MX-3FHSS & RDS8000 are now available. Extra receivers are also available for both the  MX-3FHSS & RDS8000

Please check www.rcdhamaka.com

Looks like Corona has resolved their earlier issues with their receivers. I almost bought these when they came out, but then held off due to mixed reviews. Anymore experiences with glow planes flying at crowded (radio transmission wise) fields ?

RotorZone (http://rotorzone.com)

Specifically interested in reviews of corona dual conversion synthesized receivers.

Yes we carry the Corona Synthesised 8 Channel receiver   in frequencies of 35,36,40 and 72 Mhz .

We also carry the Corona 2.4 G module  with receiver for Futaba and would be getting similar ones for JR as well soon .

http://cgi.ebay.in/2-4G-Transmitter-Module-Reciever-Set_W0QQitemZ110313112438QQihZ001QQcategoryZ2563QQcmdZViewItemQQ_trksidZp1742.m153.l1262

We also have a few Corona 2.4 G receivers as well forgot to list them   >:( will list them tomorrow.

I am so happy with the corona because I can use the same receiver now on both my JR and the Futaba Transmitters and their range is like awesome .

sai

PS Ismail : I heard from Dr basu that you guys were using mobiles to communicate when checking the range of the Carona  8-) ;D

Yes, that is true. The receiver just kept working as if the TX is very near it. Its just amazing!!.. full marks for the engineer(s) who designed it. BTW, I think the receiver we tested is the dual conversion one.

Does that mean I could use this with my DX7? since i read that I can use only DSM2 receivers.

From what I understand, you have to use a Corona 2.4 TX module to use a Corona 2.4 Receiver.  So it would not work with Spektrum/JR or Futaba or Airtronics 2.4Ghz transmitters (or transmitter modules).

Make that 5  :'(

Fridays are holidays in Qatar, and it is the primary day we fly here.  And someone started their new plane, without checking their frequency with others first, and he crashed.  Luckily the guy was has been flying from before felt only some glitches, but was able to land safely.

Obvisouly, no one wants this to happen, but we are human.  And being able to forget is a one of the best gifts we have (how else would one cope with the loss of their dearest and nearest relatives, except their memory slowly fades away as time passes ?), but the side-effects include periodic loss of RC aircraft !

Yet another reason for 2.4..... everyone there was saying.

i am using futaba 2.4ghz system onli...... i didnt find any problem in that...... but the receiver is very precise and very costly..... so we need to take more care.....

Here is a video of Donatas Pauzuolis flying a 100cc Yak 54 plane using a Futaba 12FG. 

http://www.youtube.com/watch?v=6piJmCjAV0E

Just more proof that 2.4Ghz can be trusted with even the biggest models, and has become the mainstream technology when it comes to radio gear.  Hopefully this will also result in opportunities for beginners on a budget, as the seasoned folks move to 2.4, and start to sell their PCM/PPM radios for cheap  ;) 

Here is an interesting comparision...

http://www.simiflyers.com/pdf/RC-%202.4%20Ghz%20Radio%20Systems-Compared.pdf

Hi Guys,

I have an old Futaba T6X 'Ripmax 50th Limited Edition' 35MHz .. My quetion is can i fit a 2.4ghz module in this radio ?

If someone can answer this for me would be great..

pic enclosed..

cheers

atul g.

You should be able to do the Assan hack easily.

Sai ?

The Manual says -

Modulation : FM/PPM OR PCM, Switchable..

 ;D I think i can convert this  {:)} Superb stuff..

Man this radio is old but the technology with futaba at tat time was also superb..

Cheers to 2.4ghz & Futaba.. 8)

I think a lot has been written and said about the Assan Hack option  so no need to keep on repeating the same thing.

Saju did the conversion himself and is also planning to get the LED of his Assan Hack out so  conversion is not a big deal really.

Sai

The point was not about the quality of Assan hack etc. We all know it is inferior to Futaba ;D

The question is, is there anything that prevents use of the Assan hack on this particular radio ? I can't see any, and you seem to say the same thing.

FM/PPM  so no issue

Hi Anwar,

I beg to differ... Quality is a relative term, and I would not say that Assan is of inferior quality to Futaba. Its just that both are using different technology on the same platform. They both transmit on the 2.4Ghz platform (spectrum) the difference is only the encoding part and the number of channels they utilize. Quality of Assan is not inferior, the only difference being it does not hop frequency, so it is more prone to interference COMPARED to Futaba. However, for the price and convenience, Assan is not a bad deal :)

Both have almost the same range and response time (unless you are a sport pilot for whom microseconds make a difference.)

Both are compatible with eahother and can be operated simultaneously.

Hope I made my point :)

Cheers !!!
Saurabh

Saurabh -

Looks like you have not been around this forum long enough to see what is going on ;D  Did you know that I will defend Futaba at ANY cost, ONLY because my eldest daughter is going to get married to the son of the owner of Futaba corporation ?  8-)

Hi Anwar,

Nice to know that...

I am a Futaba fan too... no doubt Futaba is the best... but this does not mean that others are inferior... Most of the videos if you see on youtube, people would be flying JR... This does not mean that JR is better than Futaba... Both use different technology and coding in the 2.4 spectrum. So, I believe it is unfair to say that one brand is better quality or superior to the other brand... 8-)

Cheers!!!

Saurabh - I don't think you still got the point  :P The point is that we take this light heartedly !  In short, "I was just kidding" (as indicated by this =>  ;D )

BTW, if there is "no doubt Futaba is the best" as suggested by you (which is not something I necessarily agree with in all cases),  then by definition (or by the rules of English language), that makes everything else "inferior" to it, right ?   8-) ;D 

Also, radios come and go.  They are just a "means to an end".  As long as they are fairly reliable (i.e. doesn't give you second thoughts every time you come out to fly), pretty much any brand will work.  Cost, accessibility/availability, a fair amount of reliability etc etc are much more important issues, than being "perfect". I only jump into these discussions when someone tries to highlight random events and then generalize that, resulting in the scaring of others away from using those brands/technologies.  Of course anyone can highlight advantages and disadvantages of any particular brand or technology. If someone said "72 is prone to frequency clashes", that is just the truth, that is not scaring people without reason. If the reader is intelligent, they can always say "but I always fly alone so this is not a big issue for me".  But what I generally see is people take one or two random crashes and go after 2.4, while a huge part of the entire RC community is flying on 2.4 without any issues.

I don't know if anything is "bullet-proof", let alone "idiot-proof" !

thanks Anwar  :D

I agree with you  8)

btw I seriously am a die hard fan of Futaba.. no second thoughts... just wanted to try the Assan hack so went for it... :) i had read quite nice reviews about it.

Cheers !!!

Anwar

You have got me biting now... Too juicy not to!!!

Well, 2.4ghz FASST systems from Futaba... your brand of tx and rx systems... has had a well documented problem with temperature build-up inside the rx.... Deadly when you enclose the rx in foam, in warm climes, in an unventilated area of the model... remember.... Diehard fans that we all are of Futaba (when is the great wedding by the way ?).. me included (I have just bought a 6exap 40 mhz and Assan hacked with a switch as vouched for by Sai). Safer to avoid known issues and bide by warnings... dont you think?

One thing quite noticeable about the hack was the speed of response of the model... Dont know whether this is true for the FASST system

I think we had this discussion like 5 times now.  Boring as it is, the heat issue does not happen in any kind of routine usage (again, speaking from hot.. baking.. Qatar!).  If you follow proper setup, this issue is the  last thing to worry about.

BTW, show me references of a bunch of people running their 30% and turbine planes on Assan 2.4, and see if you can entice me ;D 

Lot of people must be brain dead, running their costly stuff on Futaba 2.4 in summer (in hot places), while well known alternatives "without any issues" exist (forget newbies like Assan for now !).  I rest my case :P

Anwar



Just have a look at this thread on the RCG
http://www.rcgroups.com/forums/showpost.php?p=12804973&postcount=3911
http://www.rcgroups.com/forums/showpost.php?p=12789982&postcount=3893
http://www.rcgroups.com/forums/showpost.php?p=12795955&postcount=3901

Any more required?

See I walked you right into my trap ;D

Read the whole thread for the above post...

http://www.rcgroups.com/forums/showthread.php?p=12789982#post12789982

It mentions a few juicy details like "CDI issue" with Assan.

http://www.youtube.com/watch?v=zT_Y72yxURg

Now I don't know if someone has done a similar test on Futaba, but I am sticking with  Futaba for now !  The thread does mention that the "sensitivity of Assan is higher than Futaba, Spektrum etc, and that is why it is affected".

Did I say I have NOT found nirvana in radio land yet ?!?!?

And I love the way you conveniently ignored this ;D  8-)

What a can of worms did you just open ?!?!?   :o   :D

http://www.rcgroups.com/forums/showpost.php?p=12782239&postcount=3886

http://www.rcgroups.com/forums/showpost.php?p=12794556&postcount=3898


BTW, for others watching this.....  these are issues a regular flyer would probably never see, so there is nothing wrong with Assan that we are sure of (for normal usage).

I am just preparing for law school with Saju's help !

Paging Mr. Saju... Please report to this thread immediately  ;D

If you do not respond within 24 hours, Team Futaba will be given a walk-over and declared champions forever !  :P  :P

Some fun to keep the match going till Saju gets back ( Night watch man duty ) 8-)

I'm using ASSAN from almost two years ago and had no problem until yesterday in the field... This is my setup:

* TX X8F V2
* RX X8R ( this one ¿V1 o V2?)
* RCEXL CDI with SPE 40cc engine and NGK spark plug and NGK cap.
* Mini servo Hitec behind firewall near to CDI.
* Used ferrites near receiver in all servo cables.

I thought Chan had a problem with FASST within 1 month  ;) ;D

Sai

And me or no one I know had problems for 2+ years on Futaba !

I know at least three  that have to the extent that one of them has completely stopped using his Futaba 2.4 G FASST and is considering  fixing an Assan in the same tx  ;D ;) :D.

I am happy at least the walk over is  no longer a possiblity  {:)} {:)}

I hope he never flies gassers !  ;D  At least have the ladies and kids stay a long way afar when he does ! 

And wait till Assan has about 1% of the number of Futaba radios in the world !  The real fun would begin then only ! (Just like Apple Macs are "immune" to viruses :P )

I don't know too much about 2.4, But corona has 4 different 2.4 systems which are mutually NON interchangable. so i wouldn't invest in their 2.4 system, though i would swear by the 72 synthesised. In fact i had pestered Mr. Sai to get me one in the early days.
Avijit

With the Futaba FASST he did not have to get to even the gasser stage  a plain good old OS 46 High Wing trainer was good enough to achieve what you say   and for chan again it was a Funstar 40 with a ASP 52 engine  that did the job.

So I agree with the FASST getting to the crowd requires far less of an effort  :P :P :o

The difference is that it is guaranteed with Assan ;D   See the video above !  With Futaba, it is just an unexplained event that has a remote possibility !

And again, let us have more than 5 people owning Assan around the world :P

??? ??? The reason is quite clear I know due to personal reasons you cannot admit it  so I will not push further lest it spoil a  good chance of having  a futaba family member on our forum.

BTW with the tempratures mentioned you could try to fry an egg I guess  ;) :D

But I do accept that The likes of Futaba are finding Assan tooooo  hot to handle  considering that so many guys are using  assan as seen in the same thread  .

Any way Gassers and Turbines are not what 90 % of the modeler's fly hence quite a non issue for majority of us.

Just as I said  this might happen with Assan only in the case of Gassers but for Futaba you don't  even have to get to that stage  Glow is good enough  to loose control . :P

sai

There are more than 5 in India alone  {:)}

http://www.rcgroups.com/forums/showthread.php?t=723343&page=272

This is page 272  of the above thread . I am sure you would find more than 5  :P 8-)

Anwar, why ask or argue which is better, let assan get into the world F3A,F3C, F2A etc.... and prove their worth. They don't still have a radio of their own with total software etc., The new assan radio to be launched is still atleast 9-12 months away from launch. It does not have digital trims, sliders, model match, etc...

Now you are really running out of arguments, picking on numbers meant to make a point. 

And if Assan has 5, Futaba has 20000 ?  When Assan gets to 1000, you will see that they would not necessarily have to wait a whole month to scare onlookers ;D

And Assan needs Futaba to work ! ;D



The point is, until two days ago, everyone on the forum probably thought Assan has ZERO issues. Now we have one confirmed issue, reproducible 100% of the time ! :o  As the radio gets used more and becomes more common, you will see what radios do in real life ! ;D   Like I said, no NIRVANA !


Seriously, I would like to see Assan really succeed using their own radios, AND/OR hope Futaba will reduce prices.  It has to be a win for the modeler.  In fact, if Assan forces Futaba to reduce prices, that is even better ;)

Never be a nightwatchman when the bowlers are fresh and the ball is new ;D ;D ;D

By the way just for your knowledge assan introduced the TX X8F V2 only about a year back and they had alot of binding issues in their earlier production run. So if you claim you had it almost 2 years ago when they launched the V1 in august 2007. You must be heading their development team.


http://assan.cn/main/index-news-7-en.html

Your entire set up of the assan 2.4ghz is about year or less than that. Also you had mentioned earlier that you don't use 2.4ghz may be about couple of months back........ ??? ??? ???

Rx -X8R is V2 if you are not aware. X8R was never made in V1.
Also how can you have a setup and don't know what you use

Howazzt that ;)

Katty -

He is quoting from a webpage. It is about someone else's experience, who had no issues with Assan for two years and then he crashed. Sai did not mean he had Assan for 2 years.

Take it easy, and have fun ;)

OK but still before he quotes someone else he should check facts, as this will mislead other people. And also he say i am using without referring to that its someone else quote.

One thing is clear in these threads, locally we use whatever we can buy and really don't have much for or against any specific product. As long as the stuff works its the best since we haven't seen anything or been able to get anything better. Possibly thats purely on account of non-easy availability of a variety of these products. So, we will end up quoting ppl who are more prolific in their buying and using capabilities. Thats inevitable, given the still infant nature of this hobby.

Katty ,
Feels nice to know that you are watching every word I say or write that is what Assan has done to the world of 2.4 G as can be seen at RCG itself  {:)}.
Don't worry you are the other person with a 2.4G system without any major problem reported

Next time I will submit the post to you for approval prior to posting it here   ;D

Anwar  I think you should elevate Katty's status on the forum to WATCHMAN in Chief. :D

the future is only for 2.4 ghz till some one comes up with a better idea. its always better to stick to proven radios like futaba or JR, etc. as far as asan i would think it is more for the experimenting type of modeller intrested in taking things apart and make it work better. with the way the world is going prices of radios are still on the higher side and hope fully there should be a sharp reduction in the days to come.

Major ,
Was just wondering  what would have been the situation  a couple of decades ago when Futaba and JR came on the scene similar I guess. ;D.
Innovation is what drives progress and progress is directly proportional to risk taking .

HAS ANY ONE THOUGHT OF THIS :

THE ONLY THING THAT DOES NOT CHANGE  IS THE FACT THAT EVERYTHING CHANGES  ;) ;D

Sai

Saju... say something dude...

Did you chicken out ?  ;)  Or are you not feeling well or something ?  :-X

Guys,

Just received a 2.4GHz Dx6i. I had originally thought about going in for Futaba, but then the price of Dx6i Tx + Rx  @ USD170 was a bit too much to resist.. Looks impressive.....

Pankaj

At the 6 channel level, Spektrum 2.4 is a better choice than Futaba anyways. 

See this : http://www.rcindia.org/radios-and-receivers/is-this-a-good-radio-offer/

Anwar

No I didn't chicken out... Had a few in-law health problems and pending work at home to be finished.

Well... Here I am back.. But the topic seems to be a bit on the stale side...
You crying out for your in-law Futaba and me going out against...
I think we should trade places... You fight against for a change and then me for Futaba .. what say?...

After all we are all human and change at some point is inevitable... Whats wrong in change of attitudes?... You see I have a young daughter too coming of age... I have to look out for her as well!!

Saju

Guys ,
I think a lot has been said and written on this thread , I think there is going to be nothing significant by way of contribution just trying to prolong this thread  except for some small irrelevant issues ( for majority of us ) like what Anwar has bought out that Assan Has interference  with CDI.
Actually it would have been convincing if the same guy had tested the Futaba , JR, Airtronics and other brands on the same set up who knows they may also be having the same problem under  similar test conditions  . The fact that Assan has interference  does not prove that others don't under same test conditions .I am more convinced of such a possibility as we ourselves noticed yesterday that the Fatshark  2.4 G was affected by Throttle variation ( ESC interference )  when flying with a 72 mhz JR system.

Further to be frank Anwar the only thing this sort of thread arguments will achieve is in inconseqential post count if that is what you are looking for.

What we seem to forget in this whole affair is that every system has pros and cons like the 72 mhz has the possibility of external as well as from other radio modelers , but we have learnt to live with it by having frequency checks etc .
Futaba, JR etc  have their set of pros and cons as well and I am sure the user of these learns to handle and live with them.

The fact that guys have actually used Assan to fly Gassers and  a thread of around 272 pages on RCG  itself shows the level of confidence aero modelers globally  enjoy in them .

Hence I would  think any more discussion on this topic is quite point less  as the title suggests this is a discussion on 2.4G in general and not related to any brand , this thread is not assan vs futaba .

Anwar thanks  for elevating  Assan  to  by comparing it  with Futaba it  shows its effectiveness that in such a short time it is being compared with Brands like Futaba it surely is an honor for Assan

Sai

I will make it clear again.  The only reason I passionately participated in this thread and elsewhere is when I felt that one brand (or sometimes one technology) is being maligned in the name of issues that does not affect the routine use of the system (which is the same concern you have now for Assan).  Again, the heat issue for Futaba is NOT a routine flight problem (assuming basic setup and care instructions are followed).  2.4G use in general is fine (even preferred), as long as one takes in account the need for good receiver battery power (well, it is the case for 72 also).

I have many PMs from members here for standing up and talking about a radio system they use in all environments daily, and have zero problems. I have PMs asking why are people so hostile towards 2.4, without any reason (like in the other forums). Finally, some people asked me to calm down; since the more I speak, people seem to bring up issues that are even more arcane ("corner cases", like in engineering design). 

We have to be fair to all brands in terms of routine use, and that is the "larger than life" point ! 

PS: The thread cannot be "inconsequential" only when I start digging the dirt on Assan !!!! ;D  I hope you now realize how others felt when you were making "inconsequential" claims about 2.4Ghz in general, and Futaba in particular !!!  :P

Exactly. And, in that case, there is no need for Team Futaba - or for that matter, any other - to be declared champions.

All can - and do - co-exist. Best to leave it that way. Let significant experiences from all "camps" be reported in an objective manner without obvious aspersion/bias  and/or mud slinging.

Of course, and I hope you do realize that X or Y being declared champions was just for the sake of fun. A "winner of arguments", for the sake of arguments only !  Nothing to do with technology or capabilities of any system versus another.

I have made it clear multiple times that no radio is foolproof / idiotproof /nirvana ! Obviously, the question of declaring champions would contradict that.

And I will defend any of the other brands with just same fervor, should the need arise !

ALL I WOULD SAY IF THIS BE THE CASE SORRY TO ALL THOSE WHOM I OFFENDED , WILL NOT REPEAT AGAIN IN FACT I GUESS IT WOULD BE BETTER FOR ME TO KEEP MY IDEAS AND VIEWS TO MYSELF


SAI

My responses here is not to judge others' intentions.  But we have to remember that speaking one's mind (with no ulterior motives at all) can easily mislead others, especially newcomers. That we have to be sensitive about, even when everything we say is true and honest. 

We just do not have enough data points and test results about the newer equipment.  The newer stuff (whatever brand) has not gone through the level of scrutiny as the others.  So comparison between them have to be done with utmost sensitivity.  We all know that the brands that are shining now were also newcomers at one time.  Over time, the better ones tend to prevail and will get even more users, others will get weeded out.  It may take a long time in some cases (like in the case of Sanwa/Airtronics, which is just not getting the attention is seems to deserve); but it will happen.





 

 :-X :-X no more discussions here henceforth.

Anwar ,
You are the one who seems to have taken this discussion out of context and got  mixed up OR taken it  personal  :P .

 The futaba receiver heating problem : the discussion was not in this thread at all it was  an analysis made pertaining  Chan's Crash and the possible reasons for it , this was not to be any kind of casting aspersions on Futaba quite the contrary both Saju and me use Futaba radio's  and have been doing so for long.In fact Saju also has an Airtronics and myself a JR  hence between us we have most of the popular brands of radio's

So  please be rest assured we are not  against any brand as you make us out to be we are the type who don't mind experimenting  and thought  we would share our findings on the thread  for the benefit of all like in the case of RCG etc .

But from your  above post where people seem to have been upset   and PM'ed you rather than post their views on the forum and considering that as per you are sensitive , hence  I guess  such views are not appreciated here  by the vast majority  , hence up holding true democratic traditions from now on I would not  post such observations here and keep it to myself so as to keep the forum  a nice and happy place. ;D

Further since you talk of sensitivities  you started a thread  writing off Mhz radio's as no good titled : Why FM radios ( 72 Mhz etc ) are not a good idea anymore ?
When you started this thread  we did not have Assan and other affordable 2.4 G alternatives available here in India so these were accessible only to those few who could import them.
So the only option  to start the hobby on a budget was to buy cheaper Mhz Radio's .

In such a case was you starting such a thread not being prejudiced , misleading  and insensitive to those who use them  including for beginners  who cannot afford 2.4 G  systems like Futaba / Spektrum/airtronics  :P ,

BTW me and Saju are not the only ones using these radio's here  so is this not being insensitive to the regular class aero modeler's who cannot afford OR choose not to switch to 2.4 G  ?

So if you think you are the defender of those who can't speak for themselves  then I will  say that you have also been insensitive in this case  as well .

I  have done my little bit towards making this hobby affordable in India in the past 2 years  so I am not some kind of devil's advocate against brands , but am always trying to push the envelope with affordable reliable alternative's  , if that hurts  branded products I am sorry I cannot help that , BTW I also sell Branded Products as well  ;D.

sai

May be I am !  8-)

But from a third party angle, people would notice that until true criticism came about the Assan stuff, the thread was not "inconsequential" or "vain increase of post counts".  Or it could just be me again !  ;D 

Plus, it was fun !!!

My two bits worth on all this:

Guys who need to PM rather than post are not sure of themselves or gutless or both.

I personally feel that  Anwar  has come on a bit strong with a "me Tarzan, you Jane" attitude. I also feel him to be sincere but the manner misjudged and/or misplaced.

Sai. I see no reason for you to give up although I can well understand how you feel.

Is there a way to block the view of posts on a particular thread? Something like user settings... 8-)

;D  Not really bothered by such things , I guess the phenomenal growth of the forum in a short period is the cause for this feeling  . I do understand the situation  so no hard feelings from my side . One can get carried away .

But all the same Anwar has done a great job  that discussions can be this open  {:)}.

Sai 

Exactly, the forum is truly an open forum for discussion and nothing seems to read as personal. But can we similarly also discuss brands for batteries, servos, etc. in addition to just Txs. At least we learn what to buy and what not to buy.

I started that list/thread only to prove the point that 72Mhz suffers from as much or more of the issues that you were digging into on the 2.4Ghz side, and I made it clear too.  The fact that on 72Mhz you are at the mercy of others is well known and understood, and people need to know that (in the odd case that did not know it already).

But saying that a plane kept in the shade crashed at 8am on a "NOT hot, cloudy day" in Chennai due to Futaba FASST heat issue, and then repeatedly claiming that Futaba FASST is risky for routine use because of that; I felt that was unjust and I responded to that.


Sai and I are very good friends, and I intend to carry it to my grave !


The forums success or growth has nothing to do with this thread/subject. I would do the same in any other forum, as some of you may have seen already. I do feel that it is nice to have no fear of censorship here.


In summary....

I felt something is unjust (so did some others), and I spoke up. I will do it again !  Anybody else is welcome to do that too ;)

Moving on to batteries...  Which brand do you like Sai, so that I can start with another one ? ;D

being sensitive  :-X :-X :-X

Please note that there is a  difference between being or read as personal and a personal opinion.

Most opinions, would, by nature, be personal, based on their knowledge and experience.

Sushil ,
I agree and would advice them to let the shirt down and enjoy life  even at the risk of increased PM activity for Anwar  ;D

It could also be that they are not used to such "freedom" !  

Or even more likely, they thought that someone is already voicing their opinion, so why jump into the fray ?

Not speaking up does not mean "gutless". You can be in any team and offer support and advise, but does not necessarily have to be vocal about it.

Speaking up in private and not in the (public) forum, would surely indicate a fear of "standing up and being counted."

It could also be a sign of modesty, especially when others (for example, Ismail) are already expressing disinterest in the thread/discussion ;)

I am not sure if a lot of "me too"s would add any value to such discussions, unless of course they had something new/unique to contribute to the subject matter.

Hey Anwar,

While some of us are arguing about whether to move to 2.4GHz or not, another thread is started on 2.4GHz becoming obsolete.

One thought for the proponents of the MHz models might be like "why change? its going to become obsolete anyways"

cheers

Pankaj

The main reasons for change from Mhz to 2.4Ghz is the avoidance of frequency conflicts.  2.4Ghz is also less prone to other types of interferences due to the nature of the "spread spectrum" technology it is based on.  The convenience of not having to ask around before take off would be significant to many, especially in crowded fields. And these reasons are valid right now.

Asking whether one should stay on Mhz because 2.4Ghz would become obsolete some day in the future is analogous to "would you not buy or upgrade to a Suzuki Swift from an Ambassador, because the Swift will be obsolete some day?".  Even that is not a completely correct analogy, because there are better cars than the Swift today, but we do not have a better technology than 2.4 right now (I mean mass market ones).

what is available now only can be taken.  you dont postpone the purchase of your first  mobile phone because 3g comes after 2 years then only i will buy. the same logic applies. free your mind be happy with what is there. all said and done we all are flying. better to fly with peace of mind. happy flying.

Yesterday, a flier experienced TOTAL control failure on his  brand new FUTABA 10 CAG + 617 FS. He had an earlier flight without problem. The battery was a 6V - 2650 NiMh pack, about 8 flights old and fully charged the previous day.

After the crash, the radio system was found to be functioning normally.

What can one look for except the usual culprits that have been eliminated already.

1. Was the voltage of the receiver pack verified after the crash (not just trusting the previous night's attempt to charge was fully successful).

2. Are all servos still working well ?  Any that are stuck etc ?  Would any linkages be stuck at extremities of stick movement, causing high amp draw ?

3. Was the model kept in the sun prior to flight, and was it a hot day with bright sun ?

4. Is the flier being totally truthful ?  Did he lose control while doing simple routines, or was the aircraft  already in a bad orientation when the crash happened, and it is easy to blame the radio for not being able to recover ?  >:D  (No disrespect, but I have seen this attitude multiple times).

5. Any lose contacts/connections in the wiring ?

6. Finally, put the same receiver on a less worthy plane, and try flying it a few times.

So many possibilities and things. I have had a crash on 2.4G Futaba 2 years back,when 2.4G was new but then Futaba admitted their fault and replaced it. Now, i would say that the usual culprits be scrutinised more before really blaming the radio. There are so many factors. Here is a small list that i would start off with :
1. Ensure if it was really control failure or lack of orientation etc.
2. After crash, check battery/connecters. Discharge battery and note voltage/current
3. Check if there was a control surface/linkage failure or any structural failure
4. Check antenna placements / vibration of model

All this has probably been discussed before. Without indepth details and first hand information nothing can be said here.

1. The Tx was taken over by a very experienced pilot. No control possible.
2. Checked/OK
3. Checked/OK
4. Checked/ No obvious problem


1. Yes.

2. Yes.

3. Was an overcast day.

4. Agree with you. Very will admit to "finger trouble". But, as above, an experienced flier took over the controls.

5. Re-checked after the crash - vertical dive into the ground, engine possibly damaged, radio worked - and still does - fine.

6. He'll need to find a plane one would not worry about writing off ! But I suppose that's all one can do now.

That itself is a bit weird.  Usually, the amount of time required for a physical hand off of the radio is always problematic, and has mixed success.  Of course, a buddy cable setup is much better, and generally works (assuming it has been well tested before the flight). The person taking over usually gets very little time to react, unless the model was doing some kind of level flight or going up.

I cannot understand what is weird by someone taking over a Tx in an EMERGENCY situation. And this was mentioned in the context of the second, experienced, pilot who found that none of the controls were responding, eliminating the possibility of "the flier not being truthful".

The flier who lost his aircraft had adequate experience to be flying solo and the use of a buddy box does not arise in this case.

The weird part is a reference to the short time window.  I believe what remains is a model that has had a head first crash, and I am not sure if the second flyer got adequate time to be of any help in that short time frame.  Do we have confirmation that he had enough to check for control input before the model hit the dirt ?

Also, if the aircraft had a head first crash, I am not sure how confidently someone can determine if the linkage rods etc where binding/stuck etc in some stick positions.  While leaving open the possibility that there is defective equipment (after all it is all electronic components), I am still not sure if all common sense possibilities have been eliminated.

I will repeat that the question is not whether the second flier had time to recover but that he found no response to his inputs.

As I have said in my posts on this, the usual culprits have been eliminated. Was looking for inputs beyond that, things that our - local - collective "uncommon" sense may have overlooked.

And what I was trying to get clarification (obviously at the expense of getting on your nerves :giggle:) is whether the second person had enough time at all for verification of response to his inputs before the model hit the ground ? After all, it is a matter of seconds and fractions of seconds.

I would suggest that a foamy be flown a few times using the same receiver in the same location for the next few flights.

i have a question, did this happen to only this guy or most of the fliers experienced glitching that day or time  :-\

Sushil,
I have  seen one such crash myself and have heard of 2 further crashes on FASST the most likely culprit in all the cases was receiver heating  and/or low voltage  resetting .
You might find some answers in this thread :
http://www.rcindia.org/radios-and-receivers/crash-on-futaba-fasst/

All these were attributable to the fact that the receiver did not have sufficient air flow over it .

Sai

Sai

Whatever. And if that is a likely cause on an overcast day then I think that FUTABA has a lemon. I just cannot fathom how and why a receiver should overheat. They do not need much power and the only possibility is the microprocessor is dissipating a lot of heat. It also seems to be a not uncommon problem.

Any which way, even if these incidents are isolated, they are indicative of a not fully developed technology. I also accept the advantage is in the impossibility of frequency clashes. But that, to me, is the only tangible "pro". The "cons" of these type of problems still outweigh that, in my opinion.

Sushil ,
This might be of interest to you :
http://www.aaccmac.org/documents/2.4FutabaCautionNotice.pdf

Sai

Ah, so that's the game being played  >:D  We have a huge thread already on why a receiver can over heat when servos go bad or when the linkages are stuck causing higher amp draw by the servos.  That, coupled with Futaba's poor choice of components with a 60celcius temperature tolerance does pose some risks unless you follow a few common sense best practices.  Still not a problem, unless you are careless in your setup.

I feel sad for all the people who risk their gassers, turbines, expensive helis and scale planes on the Futaba lemons (all the while they have access to many other 2.4 brands and technologies) !  And no clue why it is a major player (if not the major player) still in most fields around the world.

And there are other brands of 2.4 with no real issues reported in any sizable quantities at all yet (ala Airtronics), in case anyone feels adventurous enough to go for the tangible "pro" (without these "types of problems"). 

It always boils down to one crash, where people think they have investigated and eliminated every common possibility. And even when all such items are meticulously eliminated, it is not uncommon to have a single bad receiver.  What we seem to excel in is generalization.

PS: Where did I leave my list of the "types of problems" affecting 72Mhz ?

oh come on 72mhz or similar band are not that bad

Sahil - I have a synth 9C and a recently acquired 7C (got it for $60, from RCU classifieds ;)).

I am not against 72Mhz, and that was just a sarcastic reference. I converted from 72Mhz not too long ago, and still use it for buddy training etc.  But I hate these generalizations and scare mongering based on one off incidents.  Some people accuse me of the same when it comes to 72Mhz. But the distinction is very clear, that frequency interference on PPM/PCM is a 100% reproducible issue.  It is the major reason why 2.4 was invented in the first place.  Stating such a fact about Mhz and generalizing based on rare incidents about 2.4Ghz are two different things. 

I hated the stickied post on the other forum that scares people (who did not take the time to investigate, or newcomers) from using 2.4 technology. I wish these people tried some other brand of 2.4, in case they are not comfortable with Futaba or JR/Spektrum (something like Airtronics or Assan conversions); instead of blurting out generalizations.

for me this is the reason,now more then ever i want to stick to 72mhz or similar bands because for me its price that matters besides i will soon be getting my 9ch radio with built in synth n scanner almost near to WFSS (wireless frequency select system)so it should solve/avoid/warn major problems

also did you know there are radio system where in one can transmit on dual frequencies but this for DIY type,although i remember seeing similar commercial unit.

Anwar

With due respect to your objections, I would still like to enquire if the rx was in a nonventilated space away from all other heating devices (like batteries, esc's etc) and with no room for airflow over it ?

You see, the earlier reference to    http://www.aaccmac.org/documents/2.4FutabaCautionNotice.pdf

shows one how the Futabe Rx heat up on its own, and therefore a precautionery ensuring of air-flow over it, could mean all the difference. This is not to vindicate any arguments made here and in earlier posts elsewhere  but as an elementary precaution when working with these type of rxs'. It does not deride the fact that Futaba and Airtronics are sitting on some of the world's best model RC technologies, the difference being that Airtronics rxs', as noted by all sources of information, do not heat up. The JR/Spectrum 2.4Ghz is next in line and then comes others like  ASSAN and others.
This also does not mean that they are bad by any comparison. All these technologies have proven many times over in many airfields where typically there could be atleast 30 or more numbers of  2.4ghz fliers all working simultaneously in various assorted manners. Meaning to say they are all good technologies

But I am still looking forward to a little wedding....

Saju

Saju not again   :violent: :argue: :discuss: :giggle:
I would rather :sleepy:

Saju - That's for you ;) I would suggest that you read that paper carefully to justify your "gets heated all by itself to 60C" argument (more like 72C per the article), unless of course, other events contribute, like high amp draws by stuck servos. I am tired of repeating this.

While reading, pay careful attention to phrases like "I am trying to represent is a model that has been left on a tarmac pit area in the sun on a summer’s day" and "How much current would a stalled servo consume".  The article says cooling is a good idea, which Futaba itself says when they recommend that the receiver should not be wrapped in foam.

Sai - Me too  :sleepy:

Not sure about airflow (it is certainly a good thing, don't have enough data to say that is a requirement). But away from heat sources, right antenna orientation, and not wrapped in foam etc are issues to be clarified, and I believe they were all considered (as these are part of the "common" reasons).

The 100% reproducibility is exactly the point I have been trying to drive at. With the 2.4GHz problems there is only conjecture and uncertainty. This is the real issue.

Also, even if Futaba has issued an advisory, I consider it inadequate design if the radios cannot be used in a fairly typical environment in many countries. The same conditions do not affect other type of radios from working satisfactorily. I would also like to add that this would hold true for ANY manufacturer who dared to release a product with an inherent flaw.

Imagine a car manufacture issuing a caveat that, for example, it should not be used if there is more than 10mm of rain, or some such thing.

Basically, if one product and/or technology cannot work in the same manner, in common conditions as ALL OTHERS, then there is a flaw, and a deep one at that.

But we have drifted a bit and come down to Futaba specific problems because my report just happened to concern that brand. What about other 2.4GHz radios?

Anwar


Well what is bound to get heated gets heated when powered up whether you like it or not... Look at your standard PC... The Pentium chip for example gets heated up just doing the functions at high speed... The higher the speed the higher heat it dissipates and therefore the higher the efficiency of cooling one has to provide. The same thing goes here as well. This doesnt stop you using it.
The microprocessor (Micro-linear ML2724) has to do a formidable task of checking for blocked and unblocked frequency bands continuously at very high speeds and successfully transmits its signature in two of the free bands simultaneously in the Tx. The Rx also has a similar microprocessor running at high speed to unravel the signature from the right bands, authenticate it via the tx signature, decode it to the different channels at 1.5mbps.
 The technology is superior, but with cautions... whether it is Futaba or not is not important, when it comes to Physics.

Cheerup man...

In common conditions, there is no issue, is what I have been trying to say all along.  Just make sure the receiver battery is strong, antenna orientation is OK, do not wrap the receiver in foam, and make sure your servos and linkages are setup right (not binding).  These are the simple rules everyone I know have been following for Futaba, and they have been fine so far, in the blazing hot conditions in Qatar (yes, NO one flies at noon in summer!). You may call that "lucky", but those are the facts.


I have said time and again that Futaba made a poor choice in terms of component selection, so that they missed an opportunity to accommodate an even wider range of temperatures and operating conditions (like people not following proper setup instructions). Again, this is not an issue for routine use.  Other brands are even more accommodative of such excursions.  Just try Airtronics 2.4, if Futaba 2.4 gives you sleepless nights ;)  But there is no logical reason to completely bad mouth this technology, that is seeing wide-spread adoption.

But people just go on generalizing against the use of any kind of 2.4Ghz use, which defies and all common sense (and common sense of the majority of RC users who are already happily flying 2.4G !)  It seems that a conscious decision has been made to bad-mouth this technology, until the day arrives when they also buy a 2.4Ghz radio (for whatever reason ! I hope they all receive one as gifts from somebody who cannot take this anymore ;D)

Anwar

I dont think any one is generalising here about 2.4Ghz use... There is no question about 2.4Ghz being good technology... Since Futaba came out with one of the first FHSS systems, they used an earlier processor which so happened to have this limitation on temperature. Others who came later skirted around this problem, their own way or use of later more advanced technology. This does not in any way deride 2.4Ghz or who ever use it, me included...

Saju

Unforunately Saju, that is not at all what I see from other posts here, and elsewhere. Just read through the posts here carefully.  You can find even more glaring examples elsewhere.

Time to put a lone sticky post on the "Radio" board which proclaims 2.4Ghz is more dangerous than the H1N1 flu ;D

We are all intelligent enough to see that radio technologies and brands come and go. But having a closed mind on something that is being widely adopted begs for questioning.

PS: And my fingers are tired of questioning  :banghead:  :giggle:

Ok, I am a little concerned here. We know that the Futaba Faast Rx is susceptible to problems due to heating. Now, wouldnt 6V battery pack (A123 even more ) , heat up the Rx ore than 4.8V ?
Also, if we use high torque digital servo with a huge current load, then wouldnt the Rx heat up ?
I noticed that the 14ch Rx was slightly warm even after a few minutes of just leaving it turned on with 6V .
I do abide by the guidelines with the Rx installation, but still i am a little unsure about the heating issue. How do others here plan to overcome this ? or do we all just ignore this and move on ?
 

Gaurav -

Like anything in life, do not do anything that you have second thoughts about.  But try to do your research first, so that you can draw your own meaningful conclusions. If you feel uncomfortable even after that, do NOT do it.

Ever since I became aware of the heat issue, I was looking at how people are dealing with it, and if this is affecting people's confidence in deploying this.  To my surprise, I found that more people who are flying the bigger models (especially gassers) were going for Futaba FASST as compared to any other radio !

I am not sure if Futaba would be my first choice, if I had know about the heat issue.  I always loved the ease with which they can be programmed, so I went for one.  But further reading made me comfortable enough to decide that for routine use, there is no real issue as long as I followed a few simple guidelines.  I would have been just as comfortable or even a bit more relaxed with a JR 2.4 system back then.

Newer receivers are coming to the market from Futaba, and I did not do much research on how much they have fixed the heat issue in those.  May be with the newer receivers, this whole issue is a non-issue ! After all, it is only the receivers that are the cause for concern.

They do have one of the best (if not the best) 2.4 systems in terms of interference handing capability (mostly due to FHSS), and that is probably why they are doing so well in the 2.4 market !

To directly answer you, the number of gasser flyers who use Futaba 2.4 is a good indication that you are safe.  There aren't any guarantees about most things in life, so hopefully you will not take me to court for saying what I just said ;) 

Even the higher torque servos draw a safe level of current in normal use.  Only if they get stuck that they overdraw current and tend to cause issues.  The receivers are rated for 6V, so there should not be any cause of concern there too.

Gaurav
Please note that most TTL based IC technology use 5v as a standard. The 4.8v spec given is the lowest value the ICs can tolerate. The higher value of 6v provided is just to provide a sort of protection from wrong polarity by way of a diode in series with the Rx main circuit. The forward bias drop of a silicon based diode is 0.7v. So if that is subtracted from 6v, we arrive bang on the std TTL voltage upper tolerance of 5.3v. Therefore providing 6v is a non-issue.

Abiding by the guide lines in terms of proper air circulation over the Rx to dissipate heat created by its processor is important and should be followed as a good measure. Doing so in a gasser or Glow engined plane is tricky as it could mean that some of the exhaust may get collected over the rx and its compartment, especially if the plane is of balsa construction. The other way could be use of a very small fan over the rx. If you are using high torque servos which draw high current, it is best to only connect its signal wire to the rx and connect the power wires to a junction board separately connected to the battery, thus not transferring the high current over the rx board copper. But then again one has to compromise depending on ones best judgement.

Gaurav ,
Not withstanding all the tech talk  for which i don't even need a helmet to avoid  it flies way over  :giggle: :giggle:

In simple language : Rx Heat is an issue with FASST that needs to be addressed as long as you  are  firstly aware of this issue and take adequate precaution  to ensure against failure due to it you are fine  .
You might have to undo some old habits and learn some new ones  but  what the heck that is adjustment to change  in any case  ;D ;D

Sai

Nobody uses TTL components these days. If it was TTL, the receivers would not have worked reliably at lower voltages from 4 cell NiMH battery pack. Without knowing the exactly what fails in the Futaba rx, I see merit in Gaurav's hypothesis. In general the power dissipated in electronic devices does increase with voltage. The nominal working voltage of devices I have worked on developing have  been going down over the years for this very reason - reducing power dissipation. Current devices work at a nominal voltage of 1V.

It is true that TTL is not widely used nowadays... however, with the old foundries being scrapped to asian countries you wouldn't know what the chinese component manufactures have inside their products. I am a 'victim' of a chinese manufacturer who claimed good things in his component datasheet.. it worked fine in samples but in production it burnt my fingers.. on close examination its found to be out of specification!! Well, I do not mean that you may have a component like that in your radio systems. Its just my experience with electronic components...

At 2.4GHz signalling rate, it would be wise to use a 1.0V - 1.8V for power supply to conserver power and to maintain the requried slew rates. My guess would be the RF back end would be using a lower voltage (1V - 1.8V) while the Digital Front end system would be using higher voltage (3.0V - 6.0V)... So, the system to work the supply voltage should be >= 3.0V.
(Again, note that the voltage figures are just arbitary values)

-Ismail

While this is true, there is a different issue to consider.

If Gaurav is trying to be cautious, which I thought was the intention, then there is a choice to make.  One possibility is a low voltage reset, and the other possibility is receiver overheating.  Between these, low voltage reset is more prevalent, hence my recommendation that a 6V setup would be more resilient.

I didn't see where the 6V was suggested, I was responding to Gaurav's post about Futaba. I guess somewhere the spektrum low voltage reset issue and futaba overheating has got mixed up.

His question, I believe, was "is 6V riskier than 4.8V because of heat issue".  I believe heat is a lesser risk than the risk of running a lower voltage on the receiver.  6V is within the rating of the receiver, and the small increase in voltage and possible additional heat generated due to that is less of a concern than the risk of receiver power going low.  The number of 6V setups people use on Futaba FASST especially on larger planes seems to confirm this.

Which component overheats in Futaba ? Is it the processor or regulator ?

Well, I agree that people are using FASST for gassers and other big airplanes, but there have been incidents worldwide. Not that i do not trust 2.4G, the technology is the future, but the FASST implementation is not 100% there yet. All these heat and voltage issues never existed in the 72Mhz, and these issues cropping up after their product release surely proves that Futaba went wrong somewhere.

Agree to this. But we live in the present and we cannot ignore this issue. The importance of this issue is realized only once you crash your model and have no explanations what caused it. We just cannot take it lightly.



and also remember that there have been a number of un-explained crashes.

This is why I said, go with what makes "you" comfortable.  Yes, these heat issues were not discovered in India, it has affected people worldwide.  But worldwide, Futaba FASST seems to be a top choice when it comes to flying large planes.  You make the pick, that suits you :)

Futaba implementation erred on the heat tolerance of a receiver chip. It is known, and acknowledged. I am not sure why it needs to be "proved".  For common use with precautions, people still seem to prefer it.  Does not mean that you or me should follow suit.

Unexplained crashes have happened with every radio technology.  If you feel the share of Futaba FASST is particularly significant, do NOT go for it.  Let the people who are trusting it now, have their trust shaken when they hit the dirt ;D  Just remember that it is a tiny minority though (as compared to the total number of people using it) !  If you want 100% guarantee (which I am not sure is achievable), you should make decisions towards that end. 

Futaba is only one of the choices, after all.

Receiver voltage is an issue everywhere, including 72Mhz.  Newer 2.4 implementations have drastically improved the reconnect times.  Heat is a Futaba FASST specific issue, not a 2.4Ghz wide issue.

Gaurav and all

The processor used in the Futaba Tx and Rx is the same : ML 2724 from Micro linear. This is a fully integrated 1.5Mbps frequency shift keyed (FSK) transceiver that operates in the unlicensed 2.4GHz ISM frequency band.

I am attaching the max ratings specified for your benefit. This data sheet specifies that the processor can operate even as low as 2.7v but subject to other components on the rx operating at that voltage. This is the processor which has the unfortunate bad habit of heating especially in the rx mode. This chip is used extensively in cordless phones. It has an upper tolerance of 5.5v for its VDD. Futaba certainly has other components interspersed to see that the voltage at this chips VDD does not exceed specs. So you can rest assured about the use of 6v.

As I said before, one has to take ones options cautiously, knowing the risks involved.

Saju

Yep, this is the one with the 60C temperature limit. 

Futaba should have made a better choice, not giving Spektrum guys a chance to come up with advertisements like these  :P

http://www.spektrumrc.com/content/images/products/challenge_AD_3.pdf

Here is an interesting video on low voltage impact on both Futaba and Spektrum/JR 2.4Ghz systems.

http://www.youtube.com/watch?v=PwnM9pBH9QM

At 3.0V, I can't see how regular (72) Mhz links can fare any better either.

at this voltage the servo will be going there own thing ;D beside one can notice non responsiveness of the plane or glitching well before 3volts !

PS: the above experience was with Futaba AM 4ch RX and e-sky servos 9 grammar's

Sponsored by Spektrum  8-)  Still quite a bit of good information.

http://www.spektrumrc.com/Content/Images/Products/calOrrSPMarticle.pdf

My all time favorite thread  ;D

The latest news is that Futaba seems to have slipped in a new set of receivers which are much more head tolerant. 

[1] The newer batches of the original "FS" series receivers have small dot (either white or gold) under the antenna. People on other forums who have tested these for heat tolerance have reported that they cannot reproduce the heat-triggering-failsafe issue on these.

[2] The new "HS" and "FF" series receivers have also been tested to be free from the heat issue. They also seem to have a gold dot.

So if you are in the market for a Futaba 2.4Ghz (FASST) receiver, please note this.

What is sad is that Futaba seems to have never acknowledged any change to the heat tolerance with these newer receivers (still the same 60C), which seems to be a business decision driven by the worry of heightening the concern for existing FS series receivers in the market. 

NOTE to Saju bhai:  As this is bad customer service, the marriage has been called off (although we continue to be friends)  ;D

NOTE: If someone is reading this for the first time, please be aware that the Futaba heat issue is not a concern for routine flying and tens of thousands are using them without issues, with the appropriate best practices applied.

This thread has a picture of the white dot.

http://www.rcuniverse.com/forum/m_8859612/anchors_8859612/mpage_1/key_/anchor/tm.htm#8859612

And here is a oven test, on an FS series receiver with the dot !

http://www.youtube.com/watch?v=3ocet0HNOJM

Anwar Bhai

"NOTE to Saju bhai:  As this is bad customer service, the marriage has been called off (although we continue to be friends)  "

Noted... Now will be the next in line ? and when will the blessed event take place ?

Saju

What is the kind of flying where it could/would be a concern?

I have a feeling you know the answer already, but here goes again  :P

The issue is not the type of flying, rather the place and modus operandi that matters.

It is an issue in severely hot places, combined with keeping the receiver exposed in the sun through the canopy (causing the inside of the fuselage to get really hot). It has also been reportedly triggered by the receiver being kept next to sources of heat inside the aircraft itself.

A large majority of people who have noticed this issue have experienced this on the ground, as the plane was on the ground exposed to the sun, and when it is time to take off, they see the led on the receiver in red as failsafe has already kicked in.  Most people move the plane to the shade for less than 5 minutes, and take off after the receiver led turns green.

The 148 page thread on Flying giants is a pretty good bed time reading, and if nothing else, you end up with some respect for the Airtronics SD-10G ;)

With fans like in the attached picture (which I just noticed on Facebook), I guess Futaba can get away with a lot  8-)

did some one say Airtronics SD-10G  8-) (mine is on its way)

what is the operating temperature of 2.4GHZ receivers sold by futaba,JR,spectrum radios ?? i know that Airtronics stuff operates upto 50C !

 :P

This has been discussed to death here ;)  Just search !

Note that newer Futaba receivers have higher temperature tolerance, but not officially acknowledged.

BTW, 50C for Airtronics does not sound right.  Futaba had listed tolerance of 60C, and people had issues when such receivers were exposed inside canopies.

okay will do  :)


link please

hmm....summer season is on its way so lets wait n see if i have anything bad to report !

http://www.flyinggiants.com/forums/showthread.php?t=29975

thanks for the link and 50c temperature rating was for transmitter not receiver (rechecked manual)

sahil

That sounds more like it.  When I was initially investigating the Futaba heat issues, I remember reading that both Spektrum and Airtronics were somewhere in the 70 to 71 Celsius limit for receivers.

happy to report that there has been a crash reported while using a ATX, now i know the system works  >:D

http://www.rcgroups.com/forums/showthread.php?p=14324319#post14324319

Visited one of our LHSes today, and they showed me the new stock of the older model R617FS Futaba FASST receivers.  All had the white dots near the antenna.

So these must be the higher heat tolerance ones.

increasing range of 2.4ghz
Long Range RC Radio Project  with 2.4 Ghz 
http://fpvpilot.com/LongRangeRadio.aspx

Avinash

Thanks for posting the link.

But range has really never been the issue with 2.4GHz.systems.

wow that's 4 times more power  :o

another technical aspect is 2.4 ghz length of  antenna required will be less than a 72mhz, u can see it. :thumbsup:


2.4 ghz will have more range than 72mhz  :thumbsup:

shorter antennas like in 2.4ghz are cool that donot render our movement.


-------------------------------------------------
and AM systems will have more higher antena length
less range  :banghead:

  :headscratch:

Gee guys, this appears to be one big advertisement for 76mhz and Corona receivers. I have both 35mhz and 76 Mhz and I'm rather reluctant to admit even some 27mhz equipment. Thankfully they all sit in storage boxes and the 2.4ghz radios are all I use. I have Futaba, Spectrum, Multiplex, Various generic brands and Turnigy 9X and 9XR and 9XR Pro. in 2.4ghz. I have 40 planes, 30 boats and 17 multicpoters all fitted with 2.4ghz receivers. I have a number of Corona receivers as well for a VHF Multplex transmitter, but as yet have never had reason to fit them to anything.

I have had one bad experience associated with 2.4ghz and that was with a Spectrum Receiver. I haven't discovered why it decides to suddenly swittch off because I can't duplicate the problem on the bench, even after repeated shock tests, vibration, hot or cold. Needless to say it now sits on the shelf along with the lower frequency gear. Apart from that one receiver and another, the identical model and make as mine are the only problems I've ever had or seen which could be directly attributed to it being 2.4ghz. I've seen Coronas drop out of the sky and behave in very unusual ways due to RF interference but as already mentioned that can happen on any frequency and more likely on the lower frequencies.

2.4ghz adopts the frequency hopping method to combat co-channel interference apoint made clear by something like 20 gentlemen playing "Let's see who's the last left flying" game with their flying wings on YouTube. I've never seen 20 flyers switch on their radios and be able to fly their aircraft immediately with any other frequency. I do however see the fact that 2.4ghz is also the band used by thousands of different gadgets around the home and offices, from TV re-senders to garage door openers. In fact a Gentleman very close to my home and even closer to the flying field is using one of those very dirty and nasty 2.4ghz expanders. Or to use it's correct name Amplifier. No matter which frequency my receivers are listening to his Modem's Wifi amplifier completely wipes out any chance of reception. Luckily I was able to quickly discover who and what was causing the problem and now we have to give his place of business a wide berth. I'm very sorry the Government saw fit to close our Radio Inspectors branch for our area.

I may be wrong, it certainly wouldn't be the first time but I see this thread as rather commercial in nature and almost an attempt to sour the use of 2.4ghz. The frequency has wholeheartedly been adopted by the vast majority of RCers and it's often the older members who hold on to what they're used to. I can understand why many don't wish to spend money on new equipment and change all those receivers, but please accept the fact that 2.4ghz isn't a problem and if it was the cause of many crashes and drop outs etc. the RC community would be screaming for change, something very easily done with today's equipment. You have many youngsters new to RC and due to their eagerness to have the right equipment they are easily misled when seeing threads hinting to problems with 2.4ghz. It's inexpensive, sophisticated and reliable, exactly what they want, why try to change that which shouldn't be changed, unless there's more profit in 76mhz of course.

Sorry for the ramble and sorry if I got the wrong message from this thread, it certainly seemed rather suspicious to me and I thought it needed comment.  Stu.

perhaps you could check the date of the last post ? 

@propfella sir,
Here's an example of a person whom i like to address as Sir.
His very politeness deserves it...

@saikat sir
Copy to you.
You'd be aware of the context - how to address people you've never met...

Perhaps you can explain why this post appeared in my "Recent Posts"?

The matter isn't exactly dated. I was concerned that new RCers may see this thread and wrongly assume there was something amiss with using 2.4ghz. A good reason for making my post I feel. Does any topic related to RC really become dated. I'm still using similar items I used during my first build, back in 1957. Obviously 2.4ghz hasn't been around that long, but has 2.4ghz changed much in 5 years?. I'm sure many people would see the thread's heading and not see the date, after all it is in rather a tiny font. Perhaps my post brought it up to date. :)

KK Iyer, Hello, I see you mentioned me in your post but I'm afraid I don't quite grasp the meaning of it. Perhaps you would explain further please. Thank You.   Stu