Finally snagged a Zenith tube radio

[mhardy6647]

oh, you can open it... don't do it with it plugged in unless you're comfortable working with HV. That admonition would apply whether or not it's got an isolating transfomer in the P/S!

You can (and might well want to) buy an isolation transformer for bench use, testing, or routine use of a "killer" chassis radio or TV. You'll note that the knobs are plastic on the radio...