Observations indicate that jets (i.e., charged particle beams) are emitted from the central black hole sources of active galactic nuclei and quasars. Magnetic fields are produced in e(-)-p or e(-)-e(+)-p jets when electrons (and positrons) are slowed with respect to protons in the jets. Interaction with an ambient interstellar gas or external radiation field can cause such drift velocities. Calculations for the magnetic fields and surface electric fields produced in axisymmetric charged particle beams are described. 5 references.