Small size. Frequency range 80--120Mhz ( input 1--1.5W) 140--170Mhz (3--4W). Power : DC 24--26v current: 5-7A. debugging steps: Welding completed, installed radiator First, do not install MRF9120. Connect the power supply 24V adjust the bias voltage of 3.5V and then disconnect the power supply. Install the MOS power tube MRF9120, pay attention to unplug the electric soldering iron, soldering iron welding using waste heat, preventing electrostatic breakdown of MOS power transistor. connect the power meter, dummy load, first turn on the power, adjust the quiescent current, 200--800MA, 400MA is the best. the test power connected to push, push, push FM maximum 1.5W, maximum VHF 4W FM and VHF, the basic do not adjust, promote the UHF Max 7W-8W, UHF adjusts the variable capacitor to obtain output power. Warning: input maximum FM VHF 1.5W, maximum 4W, maximum 7W-8W output UHF, maximum 100W, Output Disable open circuit, short circuit. Colour:green Material:plastic Package Contents: 1 x RF Power Amplifier Board AMP kits Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.