25 Oct
2025
25 Oct
'25
12:34 p.m.
On Oct 24, 2025, at 10:37 PM, ben via cctalk
<cctalk(a)classiccmp.org> wrote:
On 2025-10-24 6:29 p.m., Murray McCullough via cctalk wrote:
According to "200 Meters and down" by Clinton B. DeSoto, the silicon and
carborundum "detector" were both invented in 1906, and of course galena (lead
sulphide) point contact diodes were widely used in the early days of radio.
Incidentally, the particular transistor that BBS invented was the bipolar junction
transistor. The field effect transistor is actually quite a lot older -- patented in 1925
by Julius Lilienfeld, who also invented the electrolytic capacitor -- but from an article
I remember reading as a teenager that one used selenium and as a result didn't really
work. Wikipedia says the first successful JFET is from 1945; it also cites an article
that said the 1925 FET work used copper oxide, which is a semi-useable semiconductor for
rectifier use known as far back as the 1920.
paul
I had forgotten that 75 years ago, Oct. 3, 1950,
the transistor was
invented leading to integrated circuits making possible personal computers
and the interest of our love of computing. Where would we be without
Bardeen's, Brattain's and Shockley's invention?
I HAVE NO idea.
When did the point contact diode come out? Radar was the big tech then
so any use of solid state diodes would be Secret Information.