You will need an external switch (foot pedal) to put it in transmit mode on any band. You can wire a relay into your mic cord that will key the amp when you key the radio. This is the better way to key an amp than how cb amps are made. It doesn't hot switch the relay and no chattering issues with a ssb delay. There are many ways to key the amp and it's not complicated. All HF amps will be like this unless some hack puts in an RF sniffer type keying circuit. Ameritron uses a 12 volt circuit for the relay. Heathkits and other old amps might have 120v or more. This is something to keep in the back of your mind. Don't expect much of a warranty on a cb amp. No one will warranty transistors and you're buying an illegal product anyway. It is a buyer beware market. If you want a 500 watt amp buy one that will do 1000 and run it at 500. Being cheap will catch up to you.