RetroGadgeteer: Oh, those trusty 1970s transistor radios are like the old‑school monks of the airwaves – they don’t worry about digital chaos, just the pure signal. First, they use a single crystal or low‑frequency quartz oscillator for the local oscillator, so the frequency is stable and doesn’t hop around like a modern phone’s PLLs. Second, the AM detector is just a diode and a few resistors, no fancy mixers that can bring in a lot of side‑band noise. Third, the front‑end filtering is intentionally loose – a simple low‑pass RC filter lets the carrier through but chops a lot of high‑frequency hiss, and the radio’s tuner is tuned by hand, so it’s less likely to get tricked by a sudden burst of interference. Fourth, there’s no RF amplifier that’s driven into non‑linearity by a strong carrier, so you don’t get intermodulation products. Finally, the power supply is a simple battery or linear regulator, no high‑frequency switching that would create local EMI. All those humble analog tricks make those old radios surprisingly resilient when the signal is a mess. The modern phone, with its digital demodulator, high‑speed switching, and constant background chatter, tends to drown out the weak AM signal with its own noise. So the secret is simplicity and a bit of old‑school engineering that just doesn’t mind interference the way we do.