[bobk9eui]

A few years ago I refurbed a 40-180 for a friend. Physically it was mint. I tested/replaced bad tubes and recapped where necessary. the radio worked fine but I was really disappointed in the audio response. For a radio with a large speaker it sounded like a typical AA5 table radio with a 4 inch speaker.
SO I added feedback to improve the low end response as well as some power supply mods. Well worth the effort IMO. This may also apply to other sets.

[Ron Ramirez]

Very good info! Thanks for sharing!

This would also be applicable to the 40-185 and 40-190. If you were inclined to do this to your 40-150 or 40-155 table model, this is applicable to those as well. All five chassis are basically the same, only minor differences between them.

Philco added audio feedback in the 1941 versions of these sets (41-250/255/280/285/287/290/296/610), using a tap on the output transformer secondary.