Controller beep twice, in CE mode as well ?

[isopro]

Yesterday during a Ground station 500m range mission, i lost Control Link at arround 490m, so i checked my battery voltage and everything seem ok, then i tryed to see if i could switch to CE mode and screwed the lower screw on the back of the transmitter counter clockwise, turned controller on, 2 beeps again. So i plugged controller into pc and noticed it was still FCC mode even with the screw counter clockwise, switched to CE in software, turned off controller and back on, 1 beep. So i putted the screw in FCC mode with software still in CE, turned the controller, 1 beep with screw fully clockwise in CE mode...

Do anyone know what is the real FCC mode and real CE mode, because now im confused, i can get 2 beep with screw in both positions, and 1 beep with screw in both positions, controller came stuck in 2 beep mode with screw fully clockwise and only give me about 490m range. And the screw look like its doing nothing on the beeping. I wish i add something to check rf power of my controller in all those 4 possibilities...

Anyone seen this ?

 

[Geoelectro]

I just tried mine. Fully CCW, one beep. Fully CW, 2 beeps. Bottom adjustment of course.

Geo

 

[isopro]

I just tried mine. Fully CCW, one beep. Fully CW, 2 beeps. Bottom adjustment of course.

Geo

This is a Video of me trying, with the screwdriver,
[youtube]https://www.youtube.com/watch?v=xoNxLSEV3u0[/youtube]
And an image of the inside of my controller

It's like the screw do nothing, to the controller beeps, but does it change the power output is the question im asking myself, and maybe it works reverse, i really wonder...
If i set it to CE mode in my computer, i only get 1 beep after, but if i turn the screw fully clockwise it stay at 1 beep only..
You do the adjustement when the controller is turned off, anything i did wrong ?
P/S: I've the controller with the USB port outside...