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  .
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    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     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

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 

Quote from: rcforall on March 19, 2009, 10:35:58 PM
PS Ismail : I heard from Dr basu that you guys were using mobiles to communicate when checking the range of the Carona 

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.