Hi! I have started facing a problem with my quad copter. It loses the radio link completely after a few seconds of the start.

I'm using an Arduino Mega coupled with a ITG3200 + ADXL345 and running the Multi Wii 2.1 firmware on it.
For the radio control I have a Sanwa SD6G and the paired RX-600 receiver bought from RCDhamaka.

The entire setup used to work great earlier. I had to keep it all packed for 3 months as I was stuck up with work and now when I tried to get the thing working, this new problem cropped up! 

Any heads up on what should be done? 

First of all, have you checked if the problem is at the receiver level or the quad level, by connecting a servo or a motor alone directly to different channels in the receivers, thereby keeping the quad controller/arduino out of the equation ?

@Anwar sir: Yup, just checked the radio by putting up a servo motor on all the channels one by one. It worked perfectly! 

For the controller side, I checked up all the controls on the Multi Wii configurator. The sensors and the radio outputs are as they should be! 

Two things that I'm not really sure about are:

1. The receiver antenna wires are slightly bent. Considering that they are optical fibres, bending could be a potential problem for range. But then the quad was not even 10 feet away when the control was lost.

2. The receiver was positioned around 3 cms away from two ESCs. Could magnetic interference be causing a problem?

Did you try re-flasing your setup with multiwii v2.1?

Yup, I did!   

First of all, antenna wires are not "optical fibres".  And them being slightly bent (alone) should not be a problem.  You would get maximum range if you keep the thinner tips on those two antennas at right angles to each other though.

Seems like we need a bit of clarification.

1.   Does this happen when the quad moves away from you only ?  Does this happen even when the transmitter is  close to the quad ?

2.   Does this happen consistently (ie, every time you try flying) ?

You can try moving things around, and re-wiring... this has helped in the past on some issues. Try to keep the high current pulsating stuff (ESC to motor wires) away from the receiver/antennas. But then you said it was working fine earlier, so unless you made changes, I am not sure.

@Anwar sir: Checked everything! Reverting back to Multi Wii 2.0 code eliminated the problem. Maybe I'm doing something stupid with the new code! 

For now, I've shifted to the KK 2.0 FC that i bought from Adiboy! 

KK FC worked almost out of the box!  Let's see how it flies tomorrow! 

hello everybody,
i have started quadcopter with sanwa sd-6g remote control and kk multicopter board v5.5..
has anyone used it?
actually i dont know how to configure my sanwa with quadcopter..means what are the setting to be made?
can anyone help me?