[fenbach]

in some radios, like the philco model FT-6

http://www.nostalgiaair.org/pagesbymodel...014014.pdf

the neutral wire on the speaker is connected to the chassis as is one side of the audio transformer output. grounded, in other words.

in others, like the philco model N

http://www.nostalgiaair.org/pagesbymodel...006387.pdf

the neutral wire is connected directly to the audio transformer but not grounded.

anyone know a good reason to prefer one design over the other?

i did find one related post. TonyJSenior thought it wouldn't matter.

https://philcoradio.com/phorum/showthrea...aker+leads

[Radioroslyn]

As Tony said it probably isn't going to make much of any difference. The impedance of the 2ndry of the opt and the vc are so low. But grounding one side may have been done to quench any ignition noise. You can try it both ways but I think the difference will be negligible.