1903: Electrolytic detector - The book of science

Electrolytic detector
How it works
Not to put too fine a point on it
Commentary

Electrolytic detector

Radio receivers from 1903
until 1913 used
Reginald Fessenden’s bare-point
electrolytic detector
to convert radio waves
to pulsed direct-current signals
capable of receiving either
Morse code or AM signals.

How it works

A fine platinum wire
immersed in an electrolyte solution
acts as a rectifier
for a small oscillating charge.
When the oscillation gives the tip
a positive charge,
electrolysis of the electrolyte
produces bubbles
that cling to the wire
to prevent current from flowing.
When the oscillation gives the tip
a negative charge,
current flows across the electrolyte.

Not to put too fine a point on it

You mean exactly what you say about it.

Other people such as Michael I. Pupin, W. Schloemilch, and Hugo Gernsback have also been given credit for the discovery of this device; however, Reginald Fessenden, who was also responsible for the development of AM radio, was the first to put it to use. The electrolytic detector was sometimes called the Schlömilch cell, the Ferrié cell, or the Fessenden cell.

1903 Electrolytic detector

The book of science

Electrolytic detector

How it works

Not to put too fine a point on it