Where is the amplifier in a transistor radio?
In the simple case of a so called “transistor radio”, it basically consists of 4 stages. They are, and in this order, the RF stage (tunes a particular frequency or station), the IF or intermediate frequency stage that amplifies the radio signal, the detector stage that separates the audio from the radio signal and the audio amp stage that gives the final output power to drive earphones or speakers. What you would have to do is find someone with the technical knowledge to be able to modify your radio. First, they would have to come up with some sort of switching circuit to cut out the radio portion from going to the audio circuit when you want to use your guitar. Secondly, Off of the other side of the switch, add a jack ahead of the audio circuit to plug your guitar into. Then it is somewhat questionable what kind of output you would even get as if that is a portable unit, it may not be capable of more than about a watt or so of output for your guitar.
