Extending Range of a Futaba 2.4 Ghz Radio

Started by sundaram, December 16, 2010, 12:23:50 AM

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sundaram

That was the same question which came to my mind when I saw that demo video above. Wonder what was the video tx setup for the Demo 45 KM demo FPV Flight.

Video Tx are already available at 1.5Watts. It is only the Tx Power of transmission is being boosted from 10/100mw to 1 Watts. Though the Bandwidth used by TX RX is much less than the video Tx  which is likely to give more range to Tx Rx for same wattage, yeah I agree, It is always desirable to have better range on video channel than the Radio Control Channel.

If such a thing happens that you go beyond video range when you are fully in control range, You can always switch of the Tx and pray like hell, Blind as a bat, that your RTH Kicks in gets your Model within control range and FPV Screen flickers back to life.  :giggle: But if you are on purely FPV without OSD and RTH/ Autopilot then some Plus 20K down the drain.

Jokes apart, If such a thing has to happen it can be only on an inherently very stable platform which will always level up automatically, further supported by auto pilot electronics like co pilot or auto pilot/ auto leveling features of the OSD.

One should Practice flying around from behind Blind spot/ obstacle like tree or a hill in simulator and further the same in actual s model flight practice for such an eventuality. I have heard, this part of training given to UAV pilot for such eventuality to be able to get back the model in vedio range. Not sure how far it is true, but though makes sense.  

sundaram

Finally got time to repair and replace two toggle switch of Futaba 10CHG. Further strap on the booster.

First the stock rubber ducky was removed and kept safe for future use/ as spare.

Then the pigtail with male SMA was fitted at the same location of original antenna.

Next Jack for tapping the battery pack of TX for supplying 5V filtered sup to Amplifier was added after carefully cutting slot with dremel for the jack.

sundaram

Internally the pigtail u fl connector is connected to the RF card.

The DC jack' s wire is connected to battery pack through master switch.

Earlier I thought I will put the turnigy 5V filtered power supply also inside TX but since it would have remained on without an additional switch under normal operation decided to put it outside with the amp.

Photo graph of inside tx and prepared power supply.

sundaram

Some more photograph of tx from inside, assembled tx with just the antenna, and booster amp method-I where the amp is directly connected top SMA.

sundaram


sundaram

Method -II where the booster strapped behind and connected with interconnecting cable.

This is with a 12dbi high gain 2.4 GHz antenna omnidirectional.

Now this is a 1 Watts transmitter. The connectivity and servo response is good in all configuration. Only thing left is range testing with 1.5 watts 900 Mhz FPV with OSD.

Exploroman

Can this booster be made to fit the Aurora 9?

Exploroman

Also,
I'd like to add something like this on a RC car Tx as well.

sundaram

This can be fitted to any 2.4Ghz radio/ transmitter/ wifi router with 5- 10mw RF output. However you would need appropriate  (Male) SMA connector/ SMA aerial mount to take the RF output to the amplifier.

saurabhhsrivastavaa

Correctly mentioned by Sundaram.

U can use the booster to boost the range of any RC system that works on 2.4Ghz (it does not matter if it is land rc or air rc)
Any frequescy between 2400mhz and 2500mhz will work. However be careful as this is the microwave range. Keep it away from your body as much possible, specially from your head  ;)
Cheers !!!
Saurabh
+91 7977382130

nadia

I have heard from a senior electronics expert that "Messing up with Transmitters" in India is a crime.

If one is caught with a modded transmitter he/she might end up in prison. And this is not a joke!!

You are supposed to buy the transmitter as-is from the manufacturer. The government licenses every product that is sold in the open market. If somebody tries to increase the capability of the transmitter without a license, that will be considered illegal.


anwar

There are wattage restrictions on each band and the purpose that band is used for.  Ensuring the added power stays below those limits is always a good idea.
Hangar : Please see my introduction.
RC India forum and me : About this forum.

anwar

Hangar : Please see my introduction.
RC India forum and me : About this forum.

sundaram

I stand to agree with both Nadia and Anwar on what they have said.

Today 2.4 Ghz is used for most Electronics Comunications such as wifi routers, bluetooth, which are low power and range and various high powered transmissions like wimax and wireless WAN. They are even used in point to point wifi transmission over long range using directional antenna and very high power transmitter. They are of much higher wattage than 1 Watt, but of course all of them have been licensed by their respective manufacturers.

Like wise 900Mhz is used in GSM mobile communication band. There are 900 Mhz amplifiers in the range of 1, 2 and 5 watts Which are used for amplification for remote areas which can also be used to amplify the F*V Audio/ video transmitter transmission for extra range.

Using 2.4GHz RC Transmitters over 10mw/100mw depending on which country you are in itself not considered legal.

But getting arrested for it can rarely happen. If at all it has to happen it can even happen for using just a normal RC transmitter for flying if not used wisely.  :)  :)

When using such a modified device one has to be wise enough to use it away from civilization and habitations to avoid interference/ Jamming of other communications near by even though it can rarely occur because of the way 2.4 Ghz is used for communications.

saurabhhsrivastavaa

Cheers !!!
Saurabh
+91 7977382130

anwar

It is important to note that tinkering with such stuff is an age old tradition among amateur radio (HAM) enthusiasts. With all the grey areas... common sense rules the day !
Hangar : Please see my introduction.
RC India forum and me : About this forum.

nadia

Is it possible to extend range of the radio transmitters that come with cheap chinese heli. I have a chinese heli that I bought for about 2000 Rs. The Transmitter has 40MHz written on it. I am not good in electronics. I dont know what it means but I guess the range would be in a few meters.

Is it at all possible to extend the range of this chinese transmitter?

200m will be a good range for me to start off.

saurabhhsrivastavaa

A 40 Mhz tx should have a 200mt range by default (unless it is a toy remote). The lower you go on frequency, the more penetrating power you get. Have you even tried 200mts ? Do a ground test to check the range.

A typical 72/35 Mhz RC radio is known to have more range than the latest 2.4Ghz radios.
Cheers !!!
Saurabh
+91 7977382130

nadia

Quote from: saurabhhsrivastavaa on February 02, 2012, 05:52:17 PM
A 40 Mhz tx should have a 200mt range by default (unless it is a toy remote).

I have 2 trasmitters.
1)First one is supposed to be 3.5 channel one which came with a chinese Heli I bought for around 2K. This one is 40 Mhz.
2)Second one came with a toy car. only 2 switches so I assume it is 2 channel. This one too is 40 Mhz.


I have not tried testing the range of the Heli transmitter. I will go to a field soon and will check it there.

KALYANPRODHAN

The both of you are superregenerative receivers and that is why they fall in ranges.
You need Superhet based narrow band receiver for better performance. The receivers used in 2.4GHz Tx/Rx even in cheap HK models you get better range.
And donttry to increase the range as that me be legal issue because of the discrete booster stage.
Commonly available boosters as already legal and approved for marketing (withen their freq and wattage range) using those are complete legal.
So, AFAIK, sundaram sir need not worry about it as he uses commonly available items. And above all, he is well aware about interferences may be caused and takes advance care about that.

You may need this
National Frequency Allocation Plan
Just check 2nd page, remark of AJC Bose.   :thumbsup:

Thanks
We have to unite and to prove ourself to make indigenous products as well as marketing / Canvasing them. I'm sure we must achieve success if we try unitedly.


sundaram

Latest addition and improvement on the setup is an addition of 14 dbi 2.4Ghz Patch antenna with 10mtrs cable to mount it away from ground station and at a vantage point.