An effusive pyrolysis source is described for generating a continuous beam of radicals under conditions appropriate for the helium droplet pick-up method. Rotationally resolved spectra are reported for the nu(1) vibrational mode of the propargyl radical in helium droplets at 3322.15 cm(-1). Stark spectra are also recorded that allow for the first experimental determination of the permanent electric dipole moment of propargyl, namely, -0.150 and -0.148 D for ground and excited states, respectively, in good agreement with previously reported ab initio results of -0.14 D. The infrared spectrum of the nu(1) mode of propargyl-bromide is also reported. The future application of these methods for the production of novel radical clusters is discussed.