Two Types of Tube Amplifier Hum and How to Determine the Source - YouTube
Theo Paijmans on Twitter: "This morning I traveled with my tube radio to another town - a tube radio expert group offered free repairs. My precious had a hum, indicating leaking elco's.
Common Tube Amp Malfunctions: My amp makes no sound. — Tropical Fish
How to fix Radio tube amp Transformer Hum Buzz Vibration D-lab Electronics - YouTube
Antique radio - Wikipedia
Tesslor Model R601S Vacuum Tube AM/FM Radio Teardown Report - RF Cafe Cool Product