[DadsPhilco]

Thank you for the additional info about the speaker holes etc. The audio output has definitely been altered to accommodate a different impedance speaker, but that speaker isn't even there, so I don't know what all was done to it. I'll need to rework that portion of the guts. I should have stated where to find these changes, what document they are in, in case anyone else has the same question. The document is here at the Philco Phorum, under "Members Only Forums". Choose "Philco (and More) Downloadable Files". Then choose "Philco Files for Free Download". Download the file "changes.zip". One of the many change bulletins summarized in this document is for the model 84, here is the text:

Center Tap Lead (black-yellow tracer) from filament winding of power transformer is eliminated; one side of filaments and pilot lamp are grounded.
Approximate date of change: 2/1/34
Run number: 2
Service Bulletin number: 178

Exactly the changes I was inquiring about!