[RodB]

Hi Phil,

Looks like you have an electro dynamic speaker. This is a speaker that has a coil of wire that connects to the radio's power supply to create the magnetic field, generally known as the field coil. Modern speakers use a permanent magnet. The field coil is the big coil on the back of the speaker. The device on the side of the frame is the output transformer which sends the audio signal to the voice coil that moves the cone and creates sound. You can use the multimeter to check the field coil which should measure several hundred up to 2000 ohms. The other 2 pins are the transformer primary and should measure several hundred ohms. You can try using a pair of test leads connected to the primary and momentarily connect a battery and you should hear clicks from the speaker. If no clicks then connect your 9 volt battery to the field coil. Then try momentarily connecting another battery on the primary.