RC India

I have found people using Mhz Radio switch over to Ghz Radio systems. Now beginners start with Ghz systems.
What's the advantage in doing so  ???

One gets full range in air using Mhz systems also.. :)
One need not bind Rx with Tx. Its simply plug and play..  ;)
Although it is prescribed to pull up full antenna during flying..  ;D

I dont owe any Ghz Radio, nor used any..  :'(
I still use Futaba 29Mhz Radio system..

People plze share your opinion

starting with

cost : Ghz are costly than Mhz
tech: advanced in Ghz and not much in Mhz
ease of production ( for chinese) : more for Ghz and less for Mhz
range: more for Mhz and less ofr Ghz
interference: likely in Mhz and nil in Ghz
availablity today: more Ghz and less Mhz.


thats some of my view..! :salute:

Now i m more confused  ???   :giggle:

"To's and fro's of Ghz Radio systems and Mhz system...."

Don't you really mean "Pros and Cons....." :headscratch: ;D

Yes VC sir, i really meant that..  :)
I am a bit weak in such abbreviations..  ;D  ;D

PS:topic corrected

 :thumbsup:

Thanks VC sir
I think you can exactly tell the advantages of using Ghz radio systems..Or they are extensively used because of ease in manufacturing?  :headscratch:
You seem to have used nearly all types of radios  :)

Some corrections Vishvesh:

For a newcomer, who does not have back load of FM Receivers, 2.4Ghz is the way to go. I can argue to any length, that using FM is reduced only to legacy/attachment/Works for me purpose than iota of practicality. Ashok (Foamy builder) used to fly lonely 200 feet away from us without even need to ask on which FM Channel we were flying - all he had was a 2.5K worth 6 Channel Hobby King 2.4Ghz system.

A while back, we had a similar Digital SLR Vs Film SLR arguement and most of grand dandies swear with their life that Digital cannot meet film standards. But as soon as SLRs broke the 8MP barrier, the controversy died. Except for rare artistic/scenic 'warm' photos, most journalist/nature/Wildlife/Wedding/Fashion and hobby photographer today use Digital. Kodak cutting its Film production plant to 1/10 is a live proof of it.

You may be happy with the FM Radio you have, but owing to practicality, your next radio would be a 2.4G unless you have some special requirement.

Yes ujjwanna sir,
Actually planning to buy a new radio for my younger brother(in a couple of months) who keenly devotes his help in my aeromodelling, and wanna fly togather.. Have no flying chaps here in lko :(

So, just wanted to know atleast the major +point in buying a Ghz radio or add one more Futaba Mhz radio..

 :thanks:

Be Wicked. Get him a Futaba 6EX  (2.4G) or even better Futaba 7C. Also buy a after market Futaba trainer cord. This way you can train him on buddy as well.
If on low budget, go for 9 channel Turnigy/RCBazar Radio or  Sanwa SD6 2.4G system. But then you cannot give him a buddy flight.

Thanks ujjwanna sir, just collecting funds(would like to go for futaba)..
by the time let me also get trained  ;D  ;D..

I can add some points. But those may be useless.

1. All EM waves reflects when reflecting surface area distance at least 1/4 th wavelength or you can say it can pass through if the hole dia is larger than it's 1/4th wavelength.(1/4th is not so critical, here rather than Frequency)
2. So, a 2.4 GHz can penetrate more. But for 2.4GHz, the radiation power required for that length is less. So, range less or more depends upon the final stage RF power for both. So, it may vary for any freq and direct comparison is tough. Even an unmatched antenna with RF Amplifier can reduce the range drastically even unradiated power may burn the RF Amplifier. This is correct for both FM and 2.4GHz.
3. The higher the frequency, lower the reflected wave (rather it passes through) and so to transmit more length, either reflecting parabolic mirror or higher power required (Theoretically).
4. With FM, the transmit require licensing (Except some frequency), and 2.4GHz is much easier for using without separate license. Or you can say using 2.4 GHz is risk free.
5. The FM frequency channel for  similar frequency are lower (rather very low than 2.4GHz) than 2.4GHz. So, collision risk is lowered. Again, as Tx can bind with Rx, the risk of collision almost NIL.
6. Any HAM or Radio engineering book may explain more,
                                       BUT

all those are theory, don't get confuse. ;D

1. Use any trusted SET.
2. strict follow budget and remember, this is a one time investment. But you may start with any cheap set and afterwards can sell that and can purchase another favorite set as you are new in this field.
3. Get information from elderly fliers.
4. The range is not only the issue, but the antenna length and potentiometers are valuable thing and life depend on those, and here omes brand value.
5. If you start with rough use, don't purchase your favorite set at first. Even turnigy 9x of FS9x is sufficient for various operation except (or with) BRAND VALUE.

I recommend to use FS9x as it comes with type approval ;D certification if your budget permits. ???

After all all is your choice. We can suggest only. Think twice before purchasing.
Wait for January, as x-mas sell will be beneficial to LHS's and you can get some low priced things.

but the main thing is  :thumbsup:GOOD LUCK. :hatsoff:

Thanks

(http://www.freesmileys.org/smileys/smiley-confused009.gif) (http://www.freesmileys.org/smileys.php)(http://www.freesmileys.org/smileys/smiley-confused010.gif) (http://www.freesmileys.org/smileys.php)(http://www.freesmileys.org/smileys/smiley-confused009.gif) (http://www.freesmileys.org/smileys.php)

 :hatsoff:

I face a problem that sometimes when the plane is near the radio, servos automatically work and go on shaking when i start the engine or motor. But it automatically gets corrected when the plane is taken to distance..

Is this any drawback of Mhz radio systems, or there is any problem with my radio ???

i can only say is that it is prob with your radio... does this happen with your antenna collapsed of extended..??

When antenna is completely openned..

what ground range does your Tx gives when it is compleately collapsed..?? ( close the antenna and walk away from the plane till your servos start to jitter  (move on their own))

I never checked it.. Till now i have gone to field only four times..(flew twice,both crashed,two times did not flew at all  ;D)

Yesterday i went to field with my first electric plane. It(servo jitter at short range) always used to happen, but i thought that the sound of engine must be making some interference.. But yesterday it was electric.. http://www.rcindia.org/electric-planes/cessna-182/msg81918/#msg81918 .I never expected it with electric. I didnt flew the model due to the reason.

Dont know whts wrong..

the rong is with yor TX or RX.. if you can try getting it checked physically by one of the seniors there..!

THERE IS POINT IN TAKING YOUR PLANE IN THE AIR IF YOU HAVE A DOUBT WITH YOUR Tx and Rx.  you will loose your dear plane cos of the fault you already know.. even if any thing els fails on the system you will blame the Tx Rx even if it is not their fault...!!

Dear vishvesh, dude if you have tips to check radio at field, please do provide me.. :( Its sad if my Tx Rx has any problem..
Ill check it first myself at field, to check whether im not making any silly mistake.. then ill go to some senior member if i could not get it correct..  :-\

might be some internal fault... jus do some SOPs like
1> ground check: keep the plane on open ground  close the antenna and walk away from the plane till your servos start to jitter  (move on their own))
2> home check: keep the plane in one room and go 3-4 rooms away from the plane keep some one there to help u tell if the jitters start
3> full range: get one friend near the plane, get a bike extend the antenna and drive away (keep intouch with the person near the plane via phone) keep a track of how far you are going through the KM reading on the bike.

the one which will declare your Tx Rx in utter perfect conditions
1> range without jitter min 30 steps( again differs from model to model of Tx, but this is std)
2> atleast pass through 3 walls( around 15cms thick and 10 feet apart)
3> should give min of 1-1.5 KM even less than 1 or .5 will do as long as you do not fly beyond visual range

be sure to have the radio fully charged less voltage is also a likely reasons for glitches

also learn that there is no freq disturbances in that area.. high electric field (never felt or found) can also cause jitters

was searching for the site where i had read this but not able to find it will search and post the entire link...

Thanks vishvesh, Even i have been googling since the doubt on my Rx Tx has  been created..
The field i fly is my college ground, and it has high Speed internet connection towers at some building blocks. The campus as well holds Wifi network all around. I dont thing it disturbs.But i doubt. :-\

there you go... go to some other field and try...let us all know the results.. all the best...!

Thanks vishvesh, ill try it in some other field. I will try to take up my Rx with power supply and some servos with horns attached,so that i get my test done peacefully.Complete plane gathers croud here.

(http://www.freesmileys.org/smileys/big/big-smiley-002.gif) (http://www.freesmileys.org/free-big-smiley.php) May my Rx Tx survives the test..

Are you sure about this ? AFAIK , Higher the frequency, the penetration power is less through solid, and more reflection (Hence Multi Path as in F*V videos). Infact this very property of GSM Band (900/1800) MHZ the Vodaphone computer modeled back in England to strategically position its cell towers, getting much more coverage from far less towers than the mighty BT.

Thanks all,


Ive checked my radio at room as per vishvesh's instructions, everything is fine.. No jitters at all at home.

However,whn antenna is completely collapsed, jitter start after crossing four brick walls(of 230mm)..

Ill check the range very soon..

I guess this might be the reason:
refer point 23
http://www.futaba-rc.com/faq/product-faq.html#q201

if this is the case i can say right now is that your Tx Rx seem fine and can completely be sure about it once you are done with all the checks..

also to note that there might be a possible interference at your ground..!

Yes dude!

Even i am very eager to ground check my radio.but Having some academic pressure. >:(
 Just waiting for exams ( 12th of the month ) so that i may get free..

if any one needs a Mhz radio u may go to this link....

http://www.rcindia.org/radios-and-receivers/for-sale-futaba-4ch-fm75-mhz-tx-rx/msg83579/#msg83579

The biggest problem with Mhz radios these days is finding the right channel crystal for additional receivers.  Even the simplest 2.4Ghz radio is a much better proposition, as compared to Mhz radios these days (except for special applications like FPV).

you can always go in for CORONA synthesized receivers... i found them to be reliable, but if u have a doubt with their behavior on ground ... BE ADVISED not to fly..!

They don't seem to exist in 75Mhz... only 72, 40, 35 etc.

75 MHz is a approx value the exact value is 72.750MHz

spinzdude10 - where did you get this pearl of wisdom ?

You could not be more wrong.

do some more research - 72.750mhz is ch 48 on 72 mhz band

whereas 75mhz band has channels 61 - 90

Please be very very specific about what exactly you have for sale... from the picture, it seems to show 75.750 (or 760).  Please do post a close of the actual crystal frequency in your "For Sale" thread.

And let us move this discussion about your particular radio back to that thread... that has no relevance in this thread.

Dear all, just now i have come from the field checking my radio.

Here are the results:

Antenna closed: jitter free range under 50 metre.
Antenna slightly stretched(nearly a feet): Range 200 metres(jitter free)
Antenna half stretched:300 metres(jitter free)

I was fed up doing this every 100 metres, so ...

Coming on to visibility range here(600 metres):
Antenna closed: no response
Antenna openned half: response with jitter.
Antenna fully open:Excellent response without even a jitter..

I suffered a very minute servo shaking whenever a bike passed by in between the vision.
I cant even identify my brother between the trees and other people beyond 600 metres+ Road had a turn so no more distance was achievable..

Thanks all.. especially vishvesh  :salute:

I expect more range in sky.

seems to be all fine....

this is what i am doubt for...!

any ways take it to the sky....! slight jitter wont  make much problem if u react fast...!

Its working like charm in skies till visibility range on my EPP dragonfly :)...

congrats.....!  :thumbsup:

Thanks vishvesh..
it was a good experience..since i was flying after 5 months.

I saw someone using same age radio at Mahalaxmi field at mumbai.An old man with piper cub who comes with his wife every saturdays.
I shared him my problem he too had quiet similar experience with this frequency. He said its all due to interference of sound.i didnt get all he told,but i gained confidence to put my model in air as he did.