The Philco 'J5' radio (good one Chris) showed dramatic reduction in E M I buzz after implementing the circuit on my sketch. A 1959 GE clock radio also became usable after this fix.
Safety upgrade for AC-DC sets.pdf
The common-mode inductor and safety capacitor shown are from a Toshiba junker and the toroid came from a mid-70's GE color set IIRC. The common core inductor on the right is from a Zenith, but failed to block noise like the other two.. I usually save any line-voltage parts from my scrap-garden as they are VERY useful to upgrade the old stuff.
9-4 020.jpg
I never have been able to track down the line-delivered harmonic noise source but dimmer switches, poorly grounded (T8 or T12) linear fluorescent lights seemed to affect AM. Higher-wattage compact fluorescent and 3/4 lamp electronic ballasts really affect weaker FM stations.
My Philco R512 looks like a window A/C unit like Tom has pointed out,
but Philco made those too! I guess the design departments were the same. I suspect this radio was made in Sandusky, Ohio as Don Lindsley informed me there was a radio plant there in the 60s. Probably one without unionized assemblers who would willingly insert those Japanese tubes.
