Hi, my local electronic store has lots of radio tubes brand new in boxes. I don't recall exact part number but basically they are all simple tetrodes. All of the AM radio transmitter designs use pentodes or other vacuum tubes with more pins. Is it possible to build one with a tetrode. I want to use my old radio to play music from my phone nothing special. I am aware there are simple circuits like 555 timer or crystal oscillator ones but I want this to be a little nostalgic. Or should I make a 555 circuit and use a vacuum tube to amplify the output power. I am not experienced at designing circuits so any help would be appreciated.