Dear customer, if you have any questions in the process of using, please don't worry, please don't disassemble the amplifier by yourself. Please feel free to contact our customer service to help you solve the problem.HF Amplifier most effective Frequency range:20-30mhz. (Works on 15 meter, 12 meter and 10 meter). HF amplifier works with the frequency bellow 20Mhz, the output power will be lower and swr will be higher than 20-30Mhz. The connected antenna is also very important (suitable Frequency, watt and other conditions). The effect of the antenna will seriously affect HF amplifier effect. DC Power: at least should be 13.8Vcc, 14-20 A. Compact high power all mode amplifier with automatic TX/Rx switch and On/Off switch. Please pay attention to the operating details. This model can be amplify 100-150W for HF radio. Input power SSB:2-10 W. FM Output power:PEP Max 150 W(Input 10W). Output power SSB:300 W(Input 10W) PEP Max 250W (Input 5W) PEP Max. The item "TC-300N HF Power Amplifier FM- AM-CW-SSB 3-30MHz For Portable Ham Amateur Radio" is in sale since Wednesday, July 1, 2020. This item is in the category "Consumer Electronics\Radio Communication\Ham, Amateur Radio\Ham Radio Amplifiers". The seller is "walkietalkie64" and is located in . This item can be shipped worldwide.