U.S. Army Pvt. Chad Roberts performs a radio check at an observation post. U.S. Army Pvt. Chad Roberts, from Headquarters and Headquarters Troop, 1st Squadron, 7th Cavalry Regiment, 3rd Brigade Combat Team, 1st Cavalry Division, performs a radio check at an observation post during an M109A6 Paladin Self-Propelled Howitzer calibration on Dec. 7, 2006. SHARE: Download: Full Size (0.1 MB) Credit: VIRIN: 549113-Q-VKP58-879.jpg Photo Gallery