[Sean]

The antenna lug on the tuning cap would be on the front section of the tuning capacitor. There will be a terminal where the antenna coil connects. That is where you should connect your signal generator. For the output indicator you can either connect a VTVM across the speaker coil, connect an oscilloscope across the speaker coil, or just listen to the audio through the speaker. Watch or listen for a peak in the output. Turn the volume control all the way up and use just enough signal from the generator to give a sufficient output from the radio to get the job done. The signal generator should be set for a modulated output.