multiple antennas

Need some help guys/gals and others... I will try and provide enough background info on build and avaliable equipment on- hand for the fix. Vehicle: 2017 Ford F250 XLT Crewcab. (No Sunroof), : has a Bullet Proof Diesel Dual NMO Antenna Mount 3rd Brake Light. : has Headach Rack...

Is it possible to run two antennas at the same time on one receiver? I've been thinking of running an 800 MHz antenna along side the multiband the scanner (Uniden Home Patrol) came with.