The ATM1900D-1A20 from Radio Frequency Systems is a Tower Mount Amplifier with Frequency 1.85 to 1.99 GHz, Power 250 to 1600 W, IP3 25 dBm, Voltage 10 to 30 V, Frequency TX 1.85 to 1.91 GHz. Tags: Module with Connectors. More details for ATM1900D-1A20 can be seen below.