[Radioroslyn]

Ok Now things are making sense! That transformer is the audio output transformer. The thing that was throwing me off track is that most of the time it's not mounted on the chassis but on the back of the spkr.

We need to test it to be sure that the primary winding is good (has resistance) and is not open (OL) So measure the resistance from your wht chip lead wire to pin 2 of one of 42 tubes then do like wise to the clip wire to pin 2 of the other 42 tube. If good should show around a few hundred ohms. Also measure from pin 2 of one 42 to pin 2 to the other 42.

You mentioned that the spkr plugs in. Should have 4 connections, are for the voice coil and the other are for the field coil. Voice coil is mounted near the front of the spkr right behind the paper cone. We're not to interested in it but we are interested in the field coil. It's at the back end of the spkr and basically it's a big coil of copper wire that makes up part of the electromagnet that operates the spkr. Modern spkrs have a permimnate magnet (no electricity need). So we need to check it too. Unplug the spkr and measure the resistance of the field coil. Should be abt 800 ohms. On the spkr socket (on the chassis) should have 4 connections, two are grounded to the chassis one goes to the voice and the other to the field coil. The other two connections, one to the voice coil which ends up at the output transformer and the other is the field coil. If that is your loose wire it goes to the - side of the 15uf cap.