Coaxial Ferrimagnetic Nonlinear Transmission Lines (NLTL) are utilized as all solid state High Power Microwave (HPM) sources with virtually fixed phase relationship between input voltage pulse and output rf wave. Since the output power of a single NLTL at a given frequency, and of a given size, is limited by the effect of line dimensions as well as charge voltage on operating frequency, we employ an NLTL array to achieve higher power levels. To operate in microwave generation mode the ferrite domains are aligned along the axial direction of the NLTL using a biasing magnetic field generated by a dc current driven solenoid. This biasing method also provides a means of controlling the line delay by adjusting the magnetization of the ferrites using an auxiliary delay coil. By utilizing the delay coil and the primary biasing coil together on an NLTL, the operating frequency can be locked at a given frequency while the delay of the line can be independently adjusted. The relationship between the delay coil field and the corresponding temporal delay is investigated, and two NLTLs fed by identical voltage pulse shapes are combined using the phase control method described.