The PHILCO Phorum

Full Version: A B- Question On My 46-250
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Yes me again. This time I don't see any notes that I'm missing.

The black wire coming out of the Z300 transformer finds its way down to pin 7 of the 7C6 2nd detector/1st audio on the schematic. According to the schematic pin 8 of the 7C6 is B- and is common to pin 7 of the 7C6. So are pins 7 and 8 of the 7C6 common to each other?

Thank you,
Johnny
Yes. And Pin 4 is also common to them.

Here's what you missed Icon_smile Or rather what the draftsman missed. Down at the bottom of the drawing where the tube filaments are shown connected in series the tubes are not labelled but the 7C6 would be the last one in the string closest to ground. Its standard procedure to have the detector tube as being the one 'closest' to ground in a series string so as to minimize hum.

http://www.nostalgiaair.org/PagesByModel...013592.pdf