The first one you will find (probably) will be found outside the GNR entrance. The next one you will most likely find is in the electrical cage inside the Raider camp, Evergreen Mills. After that, you will likely encounter the SMB in the Capital Building engaging in battle with Talon Company Mercs. After that one, one can be found west of Jury Street Metro Station, near some train tracks. The last one calls for some exploring, as it is found in the Takoma Park Industrial region. Takoma Park is found by going through an elaborate series of Metro Tunnels.