If you make crystal radios, you’ve probably got a few crystal earpieces. The name similarity is a bit coincidental. The crystal in a crystal radio was a rectifier (most often, these days ...

Before the MP3 was the Walkman and before that was the "tranny" - the transistor radio. Personal radios existed before their mass popularity in the 1960's, but then they became a teenage 'must-have'.

Acoustic tube and Medium Earmold easy to be Replaced and operated; Replacement Acoustic tube: Covert acoustic air tube transmits more clear sound and protect the eardrum from sound wave ...

The piezo element itself is then directly hooked up to a mono audio jack for use with one of [Billy’s] crystal radios. To make it into a usable earpiece, the tip of a pen is cut off and glued to ...

Before the MP3 was the Walkman and before that was the "tranny" - the transistor radio. Personal radios existed before their mass popularity in the 1960's, but then they became a teenage 'must-have'.