Be smart, stay dumb.

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Crystal radio kit
C3 · Level 0 · No electricity Dumb as a rock

Crystal radio kit

A crystal radio kit with a passive detector and an earpiece.

$29Buy on Amazon
Amazon US, October 2026. Prices change.

A coil, a crystal detector and an earpiece. The radio waves themselves power it, so it plays AM forever without a battery. A weekend project and a lesson in physics.

Calm
Does not compete for your attention: no notifications, feeds or endless content. Does its job and gets out of the way.

Where to buy

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Survival checklist

What it survives, next to the smart one it replaces.
1
=SURVIVES(threat)Survives…
ThisCrystal radio kit
What it replacesSmart oneAmazon Echo Dot
2
Power cut
TRUE
FALSE
3
Wi-Fi goes down
TRUE
FALSE
4
The company switches off its servers
TRUE
FALSE
5
Someone tries to hack it
TRUE
FALSE
6
A firmware update goes wrong
TRUE
FALSE
7
Twenty years from now
TRUE
FALSE
8
=COUNTIF(TRUE)Total
6 of 66/6
0 of 60/6

The smart one is the Amazon Echo Dot.

Row 3

See it in the sheetIn the sheet
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Powered by the broadcast itself. No battery in sight.

Crystal radio kit

$29
Calm
Crystal radio kit$29
Buy on Amazon