nRF24L01 only works when I move my hand close to it

Hello everyone. I have built a radio transmitter and posted several questions about it. And now another problem that I have had but hadn't asked yet. The nRF module doesn't transmit well unless my hand is close to it or I'm holding the transmitter in my hands. And if I rotate antenna pointing down for example, it doesn't work at all. I recorded a very short video to show how it acts. I searched and saw a few other people had the same problem but couldn't find any solution. I have built another transmitter exactly like this, the circuit was exactly the same, just this one has a potentiometer as you can see in the video, but the previous one doesn't have. But the previous one doesn't have this problem at all. Their difference is that this new one has smaller PCB and I changed the position and orientation of Arduino and nRF24 on the PCB. Here is the link of the video: https://youtu.be/8XUPv2UmRp0

Hi,
What about the receiver end?

Have you tried moving the transmitter away from the aircraft, you may be too close and overloading the receiver.
Putting your hand next to the antenna, detunes the antenna and decreases the effective radiated power.

Tom… :slight_smile:

I’ll second Tom’s suggestion. It looks like the transmitter is an nRF24L01+LNA+PA version. In which case you are probably overloading the receiver with RF.

You can reduce the transmit power in code whilst testing.

TomGeorge: Hi, What about the receiver end?

Have you tried moving the transmitter away from the aircraft, you may be too close and overloading the receiver. Putting your hand next to the antenna, detunes the antenna and decreases the effective radiated power.

Tom... :)

markd833: I'll second Tom's suggestion. It looks like the transmitter is an nRF24L01+LNA+PA version. In which case you are probably overloading the receiver with RF.

You can reduce the transmit power in code whilst testing.

I just moved the transmitter far from the receiver but it didn't affect. And if I don't cover the antenna with my hand but I place my hand under the PCB, where the nRF is placed, it works well too.

I like short videos - full marks.

It seemed to work properly when the antenna was pointed to the left.

That makes me wonder if there is a poor connection between the nRF24 and the antenna.

...R

Robin2: I like short videos - full marks.

It seemed to work properly when the antenna was pointed to the left.

That makes me wonder if there is a poor connection between the nRF24 and the antenna.

...R

Yes in the video it worked, maybe my hand was somehow close to it or something. but just now I tried with antenna pointing to the left and it didn't work. it works best when it's pointing up. I checked the connection between the antenna and the nRF, and I tried with another antenna the same as this one and nothing changed.

Hi, How are you powering the transmitter assembly? Can you please post a couple of images of your project so we can see your component layout?

Can you check the supply voltage at the NRF when the effect does and doesn't occur?

The NRF looks very loose on the main board, have you got any broken solder joints?

What is your receiver antenna and how is it oriented?

Thanks.. Tom.. :)

TomGeorge: Hi, How are you powering the transmitter assembly? Can you please post a couple of images of your project so we can see your component layout?

Can you check the supply voltage at the NRF when the effect does and doesn't occur?

The NRF looks very loose on the main board, have you got any broken solder joints?

What is your receiver antenna and how is it oriented?

Thanks.. Tom.. :)

I will take some pictures and post but before that, I use a Li-ion battery with a 5v boost converter and supply it to the Arduino, and I connect 5V from boost converter to a 3.3V regulator with 2 capacitors and use it to power the nRF. I now checked the supply voltage and was 3.28V all the time wether it was transmitting or not. nRF looks loose because I soldered 8female header pins and I connect the nRF to the header pins (like pervious transmitter that I built). The receiver is this nRF in the picture and the head of the board of the receiver is pointing to the tail of the plane.

UPDATE: I forgot to put the image |500x334

|500x375 |500x375

erfan_m14: and I tried with another antenna the same as this one and nothing changed.

Maybe the problem is on the nRF24 module rather than the antenna

...R

Make sure the antenna SMA connector is firmly tightened - when you rotate such an antenna it can loosen the connector and it needs to be nice and tight. I've had little SMA whip antennas like that disintegrate inside from too much movement too, they aren't hugely robust.