[catwatcher]

This may not be a mystery to anyone but me. Bought a 46-420 at an estate sale last month, started restoration last week. I have schematics from Rider's and a Philco bulletin, which are very similar. Unfortunately, the chassis is not. Photo 03 shows the chassis marking on the back.
   

First, the tube complement doesn't match as there's a 50B5 where a 50L6 should be. Photo 04 shows the underside of the 50B5 socket, photo 05 shows the tube in place, and photo 06 shows the top of the socket which certainly appears to be a factory installation. The 50B5 is a Philco tube so it's probably original.
   
   
   

Secondly, the speaker is a PM rather than an electrodynamic speaker.

Finally, as would be expected, much of the wiring is different from the schematics. But sometimes it's different in unexpected places.

Has anyone else encountered this in a 46-420 and does anyone have a schematic that matches the chassis I have?

[Eric Adams]

You have a series 125. That's why the schematic for the 121 is different. Go to Chuck's website. He has the correct schematic.
http://www.philcorepairbench.com/

[catwatcher]

Ahhh. . . now so apparent. I didn't realize Philco used different code suffixes to designate different chassis in the same radio. I'll order the schematic tonight. Thanks so much for the tip. I've already spent two nights puzzling thru it.