The down-the-hole unbalance vibration exciter with the pneumatic drive is designed to treat face zone in the seismic frequency range. The modular-type source consists of a vibration generator with the automated stepped static moment variation, a hold-down unit and an in-built pneumatic percussive device to advance the facility in uncased holes. The article gives pilot test data on R and D model of the vibration exciter, and amplitude-frequency characteristic and spectral content of the excited signal.
