Chinese wall-warts and power supplies, especially ‘bargain’ ones are notoriously noisy in the RF department. Get an SDR, plug in a chinese power adapter and observe bands of noise from DC to cosmic rays.
Very true. An AM radio tuned to a weak station makes a good detector.
I’m hopeful a “genuine” Dell charger won’t be too hideously noisy. Guess I’ll find out when I get to my next small audio amp / powered speaker project...