[MrFixr55]

Hi Dan,
Divide and conquer. First off trry to differentiate between 60Hz and 120 Hz hum. 120 Hz hum has a higher pitch. Pull out the converter tube (the 6A7). Obviously, there will be no stations. We are checking for background hum in the radio here. start with the volume control all the way down. Is the hum objectionable with the volume control all the way down? If so, check the power supply. If good, raise the volume. There will be a little more hum, but only a little. Again, is the hum objectionable? If yes, where is the grid cap wire for the detector / AF tube? it needs to be shielded. In early Philcos, the cable should be within the tube shield. If outside, it will pick up hum as the volume is increased.

If all of these tests pass, reinstall the converter tube. Tune between stations. Is the hum objectionable? If not, if there is only hum with stations, the cause is the environment.

You HAMs and other experts chime in, but for some reason, sets with Ferrite loopstick antennas (late 1950s and later) seem to have less interference form modern electronic pollution (Old School Fluorescents, CFLs, LEDs, computers, IoTs (the Internet of Things), carrier current meter reading, etc. In my experience, currently at my house, any radio requiring an external antenna seems to have its signal modulated by the environment. Even battery operated radios in my house give hum. I need to move the radio outside and away from the house to get less hum, even the outside long wire doesn't help if it comes into my office. If I pull the lead-in ack outside the house, the signal to hum is much better. It's funny that a lot of audio equipment now use switching power supplies. their output may be clean, but they sure dirty the AC line.