Hello,

I built my own pavo pico with crossfire and mini imortal t antenna. But the range in 50hz is very poor. I can only go to 300m before i get a signal of 1:70. I have a tango II configured to 250mw. 
I read that i can go to 2km with the mini imortal t antenna.

Is it because i have also expresslrs in the AIO ?

Thank for you help

It's almost certainly the Minimortal T that is causing your issue. Don't believe the 2km range specification. I've read numerous reports of people having range issues with that antenna. Even TBS say not to use one even though they still continue to sell them. Swap it for a full size Immortal T and you will probably find that everything is then OK. If you need a small antenna then use 2.4GHz ExpressLRS instead.

VAS XFire Pro antenna?

Thank for your answers.
The immortal T full size is too bigger for the pavo pico. Maybe i can try with this one https://www.studiosport.fr/antenne-pour-...CAQAvD_BwE ?

The antenna linky you provided is the same size as the other full size one, but you can shape it into a nice L shape for max reception. Same problem tho using it on that small kwardkarpter, looky here:

868 MHz version for EU
915 MHz version for US

https://www.videoaerialsystems.com/produ...ro-antenna

...knowing now what it is, you should be able to find one close to where you live.

I don't have XFire Pro Antenna so i will first try with this one : https://www.team-blacksheep.com/products...rx_antenna

1.  can i put it like this ?     
   
2. do i need to power cutoff ELRS to avoid interference between ELRS and crossfire ?           
   

The answer is YES to both of your questions.