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  • Marcus Müllerfunkylab@mastodon.social
    Jul 31, 2025, 6:05 PM

    you just have to build it less badly, i.e., less sensitive to RF interference to begin with. That mostly has to do with a) engineers actually getting smarter about this, b) things getting smaller (and a short trace is much less likely a good antenna for some frequency, c) at least two-sided PCBs getting common and amplifier ICs getting more sensible.
    - "They use much narrower bands": absolute nonsense. GSM phones use a few kHz of bandwidth, 4G's bandwidths in the dozen of Megahertzes, 1000× that

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  • Marcus Müllerfunkylab@mastodon.social
    Jul 31, 2025, 6:07 PM

    - "Phones get better at managing their emissions": yeah, that's true: modern phones don't emit more power on RF than they absolutely need to to communicate. That's why you get *less* RF exposure if your cellular tower network is denser (common misconception: the tower in your neighborhood exposes you to more power; the opposite is true if you own a phone). But *power control* exists in GSM, too. So, not a new thing, not the reason.
    - "more talkative… checking GPS": GPS is passive…

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  • Marcus Müllerfunkylab@mastodon.social
    Jul 31, 2025, 6:10 PM

    @gsuberland yeah, and decoupling caps and power layout have improved so much since the phenolic single-layer PCB past of 1990's alarm clock FM radios. Plus, if you're building a cheap consumer electronics device that's not rejecting RF somewhat, you'll have to spend more money on the switch-mode power supply smoothing, so that's a positive side to cheap and electronically noisy power supplies.

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  • Graham Sutherland / Polynomialgsuberland@chaos.social
    Jul 31, 2025, 6:17 PM

    @funkylab yeah, MLCC FoM density went up roughly 20x since the late 90s, and costs dropped massively too. they're so cheap now that it's often not worth doing any cost optimisation on decoupling outside of BOM line reduction, because the engineering time costs more than you'd save over a full production batch run of a design.

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  • erincandescent ⎔erincandescent@erincandescent.net
    Jul 31, 2025, 6:34 PM
    @gsuberland @funkylab tbh despite all that I do think it's fair to attribute 90% of the difference to the technology shift. Mostly it's to do with the way the GSM slow control channel worked being particularly optimal for inducing noise.
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