[Raleigh]

Some Philcos of that era had a terminal on the antenna strip on the back of the chassis that was connected to the output transformer so you could make this connection without taking the chassis out of the cabinet. The instructions for 47-1230 say it's terminal 3. If you look at the schematic, it shows terminal 3 with an arrow pointing to "Z", and the output of the output transformer is also connected to "Z." That way they don't have to show the wire between them on the schematic.

So connect your meter positive lead to antenna terminal 3 and the negative lead to the chassis somewhere. You should be able to see your meter register an AC voltage if you are getting sound out of your speaker, but it might have to be fairly loud to register on your meter.