Cellular Alarm Communicator inside enclosure

[carealtor]

When ADT activated the alarm in our new (to us) house, the installer installed a "DSC ADT 3G4000 Cellular Alarm Communicator" on the wall outside the existing alarm box.
 
I'm wanting to move all the alarm stuff to inside a Leviton enclosure and I'm wondering if it will work to move this inside the enclosure too?  Will the antenna still function inside a metal box?  Should I (somehow) remotely mount the antenna outside the box?  Any insight would be appreciated.
 
 
 

 

[Del91574]

2 words. Faraday cage.
 
Wireless and cellular need to be outside of metal enclosures unless you remote the antenna