Cc2500 and deViation 4.0.1 loss signal

Hi at all,

I installed the CC2500 buyed on Aliexpress as the instructions say...for connection I follow the PB instructions on bitbucked site, and I mounted the antenna out of the radio on the left of the stock antenna.

At first all seemed ok but last week I notice this problem:

When the tx is very near to my Skyartec X3V (heli on the ground and radio 50 cm or less) and I rotate the TX on its axe, some time the rx lost the signal (red light is off and the heli do not respond) and than, if I walk away, the signal become stable (red light stay fixed).

I've tested the signal also walking (with trottle hold) in my home's rooms and I closed doors too, to create artificial "barriers": only in the room farthest the rx losted the signal (15 meters about from tx). The signal power was set to 100 mw.

So I ask: is it normal? is it normal when the tx is very near to the rx?

I think that the test that I done walking in my house, is normal that in some circumstance the rx loss the signal, considering that the walls may corrupt the reception; in open spaces this issue should not happen.

But when the radio is near!!!

Any suggestion to solve?

this is my mod: if someone see something wrong...

I don't know if this can help you....
I've had range and signal problems with my Devo7E & A7105 module... and the problem was the fixed id...
With 5-6 id numbers only have 7-8 meters range.... And with 4 id numbers much more meters...

Hope can help...

Two things to consider:

You say "when you rotate the Tx". The monopole antenna you have on it has a really strange radiation pattern. So it could be a directional issue.

What's the orientation when you lose the signal?

Do you lose signal in the same orientation when in that remote room?

Do you get the same behavior if you reduce the Tx power (I believe that's what "range test" mode does on other Tx's)?

I know that a number of Tx's using monopole antennas have bind issues if the are to close, but have never found an explanation as to why. Could be related, in which case it would be normal.

It's curious...
I'll prove this suggestion next week end.

Thanks Ursus

I saw the monopole antenna on Wikipedia with its donut. The wiki reports this:

<<Since electromagnetic radiation is dipole radiation, it is not possible to build an antenna that radiates equally in all directions,....>> and then the wiki speak about "angle of incedence" too

so, I'm not an "antenna specialist" but, IMO, this may be the reason of my issue: when the TX is too close, the RX is near to the donut's center (the hole) and here the radiation may be too low.

What do you think about?

About your questions I'll test this week end.

My only concern is to "lose" the helicopter in flight and ... booom

Thanks for suggestions

Then test your gear outdoors, within plain sight.
These 2.4 GHz transmitters suffer from he same issues as wlan equipment
The thickness of a wall depends on the angular the signal has to pass through.

auceto wrote: I saw the monopole antenna on Wikipedia with its donut. The wiki reports this:

<<Since electromagnetic radiation is dipole radiation, it is not possible to build an antenna that radiates equally in all directions,....>> and then the wiki speak about "angle of incedence" too

so, I'm not an "antenna specialist" but, IMO, this may be the reason of my issue: when the TX is too close, the RX is near to the donut's center (the hole) and here the radiation may be too low.

What do you think about?

About your questions I'll test this week end.

My only concern is to "lose" the helicopter in flight and ... booom

Thanks for suggestions

An antenna has a near field and a far field related to its wavelength - The dognut is the far field shape of a dipole. As other has also stated do trust or rely on any close signal strength, especially inside at 2.4GHz - test outside with line of sight and your antennas properly angled.

RM