RC India

Since I was accused of "getting defensive about 2.4", and I am tired of playing defense, let me play offense for a little while ;D

So why do you think FM radios (that is PPM/PCM systems in any band like 72Mhz, 40Mhz, 35Mhz) etc are not worth the trouble any more (as compared to 2.4Ghz radios) ?

Here is my list to start with....

1. Anyone can cause your model to crash by turning on their radio on the same channel, either by mistake or intentionally.  That is a truly uneasy feeling, which one has to suffer through every time you go flying, especially in places where many people fly together.

2. Forgetting to extend the antenna before take off results in loss of control.

3. You have hunt down the right type and channel of crystal.

4. PPM communication is susceptible to static build-ups, especially in the case of electric helis with rotating belts. 

5. One has to be careful everytime some one comes into the field for the first time, or when someone comes in with new equipment, as channel selection/assignment has to be verified. If some has the same channel as yours, you have to take turns and wait.

Point 1 and 5 are the same  8-)  :P

Point 3 you don't you have synthesized receivers .

that leaves only points 2 and 4 .
Point 2 is general reflex action which comes naturally its like pointing the antenna of a 2.4 radio towards the plane  ;D

Point 4 is a possibility accepted .

BTW have you announced the next prize that you are in such a hurry to get the post count up again. ;D
Sai

6. 72Mhz etc communication is susceptible to ignition noise on gas engines.

God, where is my memory when I really need it  ;)

The biggest point is 1 and/or 5.  So it is not only 2 and 4, there is HUGE 1 and/or 5 along with it !

Most importantly, we are just starting down the list ;D 

8)  pros and cons of Mhz radios would be a good title to build  a data base.

One other negative which you forgot is transmission on the same band by non rc transmissions.

See I have an open mind  ;D ;D not biased :P

sai

oh sai uncle how is your 2.4ghz conversion going on i heard that u shall stock these modules i might buy it for the new futaba 6exap

Here is one more.
-Hate the RX antenna spoiling the look of my scale airplane. And even if not scale, i prefer the "clean" 2.4 Ghz looks.

7.  PCM, which is the more widely used one, is known to mask interferences/glitches up to a certain level, causing small problems to go un-noticed initially.  Finally, after crossing a threshold, the glitches surface in its full force, causing loss of control/communication ("PCM lockouts") for possibly up to many seconds.

Now especially with Synthesized receivers available PPM/FM is widely used

I thought many war birds actually had an external antenna.

This thread will really go a long way to reaching 5 K fast {:)}

sai

8..  You have to properly extend and secure the RX antenna, otherwise the range is affected significantly.

9..  In addition to crystal restrictions on type (dual/single conversion) and channel, there are differences in size (mini versus full size) and "hi-lo" band restrictions.  All of these cause issues with sourcing and sharing of equipment.

No longer a problem with Synthesised receivers I can use my JR , FUTABA, W Fly , Turborix , Kyosho , Graupner  and any other transmitter on the same receiver the receiver costs 1/2 the price of any original receiver .

2.4 Ghz module for Futaba 6exap ???? Wow now thats new !!! :)

i dont think 6EX has module. please check. :)

You have to get the 90 deg angle on the 2.4 G receiver as well

People here are too advanced ;D  They are talking about this :

http://www.rcindia.org/radios-and-receivers/2-4ghz-or-723540mhz-(ppm)-diy-frequency-selectable-transmtter/

Saurabh ,
Check this link
http://www.rcindia.org/radios-and-receivers/2-4ghz-or-723540mhz-(ppm)-diy-frequency-selectable-transmtter/

And this Video :
http://www.youtube.com/watch?v=y2dk_42fpWM

Posted earlier by Atul in this thread
http://www.rcindia.org/radios-and-receivers/interesting-article-on-2-4-g-and-the-diff-between-dsss-and-fhss/15/

but since I don't know how to link it here posted the link again (Anwar please help)

Will be getting the Assan Modules soon I am going to be using one so one is spare from the 1st lot.

rethink selling your 6 eax you can do this easily
sai

Sai

WOW !!! this is kooool... I dint know this... surely will wait for this ... please let me know when u have the module... and  let me know the performance as well... Thanks SAI...


Regards,
Saurabh

Sai Let me know once you have the module... Will directly buy from you.

Thanks
Saurabh

Saurabh look at the video it is amazing

Anwar hardluck the thread has again been hijacked by 2.4G ;D ;D

sai

Sure, but see how this list is similar yet longer ? ;D

And I have not even started on LoS and weather issues !

Can you please post the link to the video...

Thanks.
Saurabh

Saurabh,
Its on page 1 of this thread.

Anwar ,
One of the biggest plus in buying a Mhz radio .
I can convert it to 2.4 G with a cheaper Module and continue to use cheaper receivers at 1/2 the price with both my Mhz as well as 2.4 G .

This is having the best of both worlds.

sai

Traditional PPM/FM is even worse, since they lack the ability to filter bad signals as compared to even PCM.  Using them just for the sake of being synthesized ?  Hmmm...

You can always get Assan 2.4, if you are looking for cheap, and have the "peace of mind' that comes with it ?

One world is "best", the other is "so so"  ;D  Why mix up the two  :P

Coming to think of it I think you can also recycle old AM tx's with a PPM Board to 2.4 G using a hack Module .

sai

Who would not love  both worlds if they  can get it at 1/2 the price of the first world :P  ;D

Want to have poll ;D ;D

wow you guys are good  ;D I wish i had tat kind of skill while arguing with my wife  ;D   ;D

am not sure if i will make sense but here goes..

as a beginner i would prefer to go in for a mhz tx since the rx cost is less and besides a person like me who doesnt get to fly except on sundays would rather invest less or invest where its required as of now..besides i dont want to get hurt if i lost a rx worth 5000/-rs over a plane worth 4k or 5k as per a beginners plane..

2.4ghz is no doubt the future & no arguments abt tat, i have used it personally and it's superb...but mr.sai is rite why waste a lot of money when u can get some hack modules & transform your older tx to a 2.4ghz plus the rx cost would be less to original 2.4 available tx..

this is just my view.. cheers..

Again, misconceptions.  Cost for 2.4 is not really that big an issue with Assan, Corona etc. Even the simple coax helis (like Lamas) are beginning to ship with 2.4 these days.  Just look at HobbiCity for cheap 2.4 stuff.

But the issue is different.  The reason I started this thread is because people are nit-picking remote possibilities of problems with 2.4, while conveniently ignoring (or being silent about) similar and much more serious issues in the Mhz bands.  The biggest problem is that they get passionate about 2.4 issues that are far fetched (and rare), while ignoring "every day" issues in the Mhz side.  How unfair ? ;)

So let us continue nitpicking Mhz stuff for more fun....

Tally ho !!!!!
Anwar go ahead and consolidate your list again I will love it .

But  the simple fact is that it makes sense to buy a Mhz radio and convert it to 2.4 .
Even in the case of a Module based Tx  buy a Mhz radio and also buy a Assan or Corona module and switch modules and enjoy the best of both worlds ;D ;D

BTW the Mhz Radios are cheaper  now a days as well that is the icing on the cake

sai

1.frequency conflicts can be avoided by having a frequency scanner in the TX like the multiplex has  
2.transmit the data on two different frequencies/ two receivers  
3.frequency monitor system in the receiver itself with fail safe features
4.GPS unit along with receiver with home option auto pilot landing  8-)

these should solve most of your problems and make HF/VHF bands more safe or equal to 2.4GHZ

to make it short one can implement the 2.4GHZ features on HF/VHF bands

sahil

opp sorry did not see the heading,I'm suppose to bang the 72mhz etc bands. I personally prefer HF/VHF bands but u guys have to remember that first all the RC bands are not legal in India or rather used for some other purpose hence we see lots of interference on the bands. I think once we organize and set standards then we will be able to reduce number of problems.

sahil

just ten minutes earlier i went to taxi my e-starter in the parking lot after plugging in battery the motor went at 3/4 throttle and rudder deflected to the left. i think it caught up a very very very strong interference indeed though i taxied my e-starter many time with 2.4 as its batt was down i took my 72 mhz.

i taxied as flying was not allowed i think govt ban policy has something to do with this


subbu

(i was nearly scared to death as the plane was facing me and behind me was a sparkling car)

The Spare Assan Module I mentioned about earlier has been booked by Saurabh.

So two 72/2.4 G transmitters on the way .

Since Anwar is not doing it here are the limitations of Mhz Radio's :

1. Anyone can cause your model to crash by turning on their radio on the same channel, either by mistake or intentionally.  That is a truly uneasy feeling, which one has to suffer through every time you go flying, especially in places where many people fly together.

2. Forgetting to extend the antenna before take off results in loss of control.

3 PPM communication is susceptible to static build-ups, especially in the case of electric helis with rotating belts

4 72Mhz etc communication is susceptible to ignition noise on gas engines  ???

5 PCM, which is the more widely used one, is known to mask interferences/glitches up to a certain level, causing small problems to go un-noticed initially.  Finally, after crossing a threshold, the glitches surface in its full force, causing loss of control/communication ("PCM lockouts") for possibly up to many seconds.

6 Interference from non RC transmissions on the same band .

Sai

PS> Anwar add some more if I have missed out any no problem ( feel  :( to see you so quite on this thread started by you to bash Mhz Radio's ) but think of the future you will also be bashing " FUTABA " as the most popular  these radio's is the  6exa futaba

I am bit skeptical on that. If you have an AM radio - no matter what freq - you will have intereference due to spark produced by the spark plug. The arc created by the spark plug intereferes with the amplitude of the signal that you transmit. It does NOT corrupt the frequency. Having said that, if you have a FM radio you will not have interefernce from the spark plug, unless your receiver is way too close to the spark plug.

As an experiment try this... take a pocket radio or desktop radio and turn it ON in your car... Note that the antenna of the radio should be close to the dashboard... better open the boot of your car and try it closer to the engine. Tune the radio to an MW or SW station (thatz AM)... now when you run your car (just idle it no need to drive) you can hear a rythmnic noise that is synchronized to your accelerator pedal... more acceleration more denser the nose rythmn. Thatz due to the increase in sparking freq as you accelerate... Now, tune to an FM channel.. do the same steps before.. you would notice the noise is considerably lesser.. And at about 1 or 2 feet distance from the engine you would never hear a glitch!.

-Ismail

All leading radio brands like Airtronics/JR/Futaba/Hitec will be discontinue FM radios very shortly most of their models are discontinued. Hence the service and support for this will also go. This another very big reason FM radios are not a good idea anymore.

Do we get service in India for most of these brands in any case 2.4G or FM  ???

Are you offering warranty as part of the support and service ? If yes  {:)}

Don't see it mentioned  in the item.

Sai

If there is a serious enough problem (I remember the wire chaffing issue on JR XP9303s), you always have the option of sending it to the US, Taiwan, Japan etc, if there is warranty support. 

Even that option goes away if the entire product line is discontinued (which, I don't see happening any time soon).  But the manufacturers have sort of stopped developing new products in the Mhz range, which is a sign of things to come (whenever that is). 

Would you buy an Ambassador car now ? :P   <=== I congratulated myself 3 times for coming up with this.  This sure will make Sai mad ;D ;D

Dear Mr. Sai,

I do not know if you are aware that for any futaba warranty or service you need to send it to Singapore.

Yes warranty is applicable on manufacturing defects the customers needs to bear shipping costs. All are radios come in from the manufacturer and carry the warranty as per manufacturer. You need to send it to manufacturers authorised service centre.

But when they stop production or discontinue a product then after a year from them discontinuing that product they are not liable to give you support or service on the same.

We are not against any technology but when a particular product is discontinued then it will not make any sense in buying it. Also we are not here to argue for the sake of arguing or adding more number of posts. But facts are facts. Every technology has a life span, even 2.4ghz will be overshadowed by newer technology in the future. But for now 2.4Ghz is the future.

All advanced aspects like software, triple rates,etc will now only come out in 2.4Ghz

Strictly my opinion .

I don't see the Mhz range disappear altogether mainly because it is widely used in FPV and UAV applications where using a 2.4 G radio is not possible as all these systems are designed on either 2.4 G or 1.3G or 900 Mhz  ( long range )
Like this http://www.rangevideo.com/index.php?main_page=index&cPath=35_22

This is becoming quite popular in the west hence if this trend gets stronger then this niche market will be good money for any manufacturer who also manufacturers Mhz radios.

Sai

Also people who do not know:

Here are some links:
http://www.jrradios.com/Products/Radios-Air.aspx
Here in the air & helis section you'll can clearly see that there are no FM radios in their line up

Spektrum:
Only sells 2.4Ghz radios

Futaba someone has already posted the discontinued list earlier and you can see from their present line up FM radios they have hardly a couple of them in FM.

http://www.airtronics.net/
Here you will see that they have discontinued their Classic range that is the FM radios.

Hitec will shortly update their site on it once they have launched their 2.4Ghz radios.

Sure  would if I can convert into a Ferrari at half the price  ;D ;D ;D and continue to operate it  at the cost of an Ambassador  and not a ferrari :P ;D ;D <=========  time to rake your brains for a better come back

Mr. Sai,
What is the cost of this assan set?

Will PM you tomorrow.

sai

But why, when you can buy the Ferrari itself (a Suzuki Swift would be a better/realistic analogy) !  No matter how much you convert and mess with it (which by the way, costs half the price of a Ferrari and the skills required to do it) you end up with something that everyone jokes about, and with no spares ;D

Good to see you finally admitting that Mhz is becoming a niche application thing ;D 

That is an AM versus FM comparison.  My understanding is that the Ghz range is more resilient to ignition noise as compared to the Mhz range.  Would love to hear your comments on this.

PS: I left the circuits world a long time ago, and that too even before getting into it too seriously.  I currently live in the world that makes things like these forums possible.

Frankly never been bothered by what others say ever . I have the confidence to execute new concepts
I go where others fear to tread and create a path for others to follow.
  

Come on Anwar I expected better come back's from you  :P  ;D ( no hard feelings )

sai

Never had an issue with that in fact  from my experience in marketing Niche markets are great places to operate in .

I would love to be the only seller of Mhz Radio's  in India. Can you imagine it from a business point of view .
But not all can be niche marketeers that requires creativity

sai

You are again admitting that Mhz is becoming non-mainstream (i.e. niche only) ;D 

Come on...  you can do it. Just say it aloud...  "Mhz is dying, everyone who is getting a new radio better go for 2.4Ghz"... ;D ;D

Just take a deep breath and repeat after me..  it is not as tough as you think it is .... :P :P

PS: My father is wondering why I am sitting in front of the computer and laughing hysterically ;D

I repeat it  as below :

"  Start
BUY  A MHZ RADIO ITS CHEAPER BUY A 2.4 G MODULE LIKE ASSAN OR CORONA  CONVERT THE MHZ RADIO TO 2.4 G USING THESE MODULES  AND ENJOY THE BEST OF BOTH MHZ AND 2.4 G RADIOS AT HALF THE PRICE ""
 {:)}

why get stuck with an original 2.4 g radio and keep paying high receiver prices when you can get it cheaper .

I have said it before and say it again I am not against 2.4 G but I will adopt it the way that appeals to me best .
And if I know of something good I will share it with guys here

Kindle the creative side of you.

Don't follow the beaten path.

Sai

PS Anwar  once again {:)} {:)} {:)} {:)}  this sort of fun could not be possible at the neighbour  without all of us getting banned

BTW just received the Assan Modules .
Got work to do see you later
sai

Cheers ----- Best Of Luck -------- :)

Anwar ,
tell Santosh his Multiplex park master arrived as well.

sai

Yes, GHz is more resistant to ignition noise. So, is MHz at FM.

I am with Sai on this. I would convert a MHz radio to GHz and enjoy both the worlds. The MHz receivers are going to be dirt cheap as 2.4GHz takes over. And more people fly in GHz, the MHz channels are going to be free... Buf if I change my mind to go with GHz, I can always do so anytime with my Assan module.

Thanks for confirming that.


That is just one way of doing things (assuming one is savvy enough). 

The point (of this thread, at least) is that everybody including you and Sai are shifting to 2.4.  In other words, why take the risk (of getting locked out by someone else) with a 72Mhz "add-on" ?  I am not sure price is enough of a justification for most people with a limited number of models. I think the peace of mind, security and other features of 2.4 are a better trade off.

Cost is something that has already come down for the non-premium brands, and is on the way down for the premium brands.

IMHO any beginner or even an intermediate flier who invests a lot of money in all the RC equipment would want to mess around with these things. converting AM/FM to 2.4 or whatever. I remember the time when i used to wait for other guys to land and switch off the RX. I surely hated it a lot. Now i am capable of converting a TX to 2.4 but would never do that as there is only Rs. 1000/2000 diff + a lot of trouble. only people with lot of spare time/money to waste or a RC seller/dealer would do that. BTW I am proud owner of two 2.4G  & one 272 MHz sets. Thx