We are developing a family of frequency agile relativistic magnetrons to continuously cover the bands from 1 to 3 GHz. We have achieved tuning ranges of > 33%. The magnetrons have been operated repetitively in burst mode at rates up to 100 pps for 10 sec. Power is extracted from two resonators, and is in the range of 400-600 MW, fairly flat across the tuning bandwidth. We are using a network of phase shifters and 3-dB hybrids to combine the power into a single arm and to provide a continuously adjustable attenuator.