When there is external input, the machine will automatically recognize and turn off the internal crystal oscillator, and amplify the external signal. Please leave note for your special request e. Please do NOT leave negative or neutral feedback without any contact. We care about our valued buyers, if you have any questions, our Customer Service staffs will be very glad to help you. This item is in the category "Consumer Electronics\Radio Communication\Ham, Amateur Radio\Ham Radio Amplifiers".
The seller is "goldenmonkey2017-4" and is located in this country: CN. This item can be shipped worldwide.