AR88D PSU question.

[Michaelr]

I think Paula has given the full answer to the question, directly heated rectifiers used to have their filament ends fed from a seperate centre tapped winding . The HT being taken from the ct point , this reduced induced hum.

ALso could you not power the Ar88 kit from a seperate DC power supply. Maybe the resistors are there to tie the filament ends to the same potential when using the external DC supply.

I am not sure why they used 2 resistors in series though.

Mike