The 6519/6521 from Vectron International is a Voltage Controlled SAW Oscillator with Frequency 300 to 1500 MHz, Output Power 7 dBm, APR(pullability) ±20 ppm min, Supply Voltage 3.3 to 12 V, Control Voltage 3.3 to +12 V. More details for 6519/6521 can be seen below.