Quote from: KALYANPRODHAN on November 28, 2011, 11:23:23 PM
I can add some points. But those may be useless.

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).

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

Quote from: abhay1290 on December 09, 2011, 09:22:43 PM
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)..

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).

Quote from: anwar on December 10, 2011, 12:39:40 PM
The biggest problem with Mhz radios these days is finding the right channel crystal for additional receivers. 

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

Quote from: spinzdude10 on December 11, 2011, 04:07:02 PM
75 MHz is a approx value the exact value is 72.750MHz

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  

I expect more range in sky.

seems to be all fine....

Quote from: abhay1290 on December 17, 2011, 03:30:33 PM

I suffered a very minute servo shaking whenever a bike passed by in between the vision.

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.....! 

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.