[mikethedruid]

Work backwards from the speaker. Start at the audio output tube. Feed an AUDIO signal through a .1 MFD condenser into the junction of C23 and R24 and the control grid of one of the 1LA4 output tubes. If you get sound then work further backwards. Feed the signal in at the plate terminal of the 1LH4 tube. See if it comes through. Then switch to modulated RF at the IF frequency, 455KC, and feed it in through a .001mfd condenser to the terminal of the 1LH4 to which the green wire from the 2nd IF transformer connects. See if that causes the audio to come through. If it does, then go to the control grid terminal of the 1LN5 IF amplifier tube, and feed the same signal in there. If it still comes through, try feeding the signal in at the plate terminal of the 1LA6 pentagrid converter. If it still comes through then your problem is somewhere in the circuitry there around the RF and oscillator circuitry. If it stops anywhere short of there, then look for your problems in the area around where it stops.