All About Circuits

Cat's Whisker, is this where the semiconductor was launched?

VoodooMojo

Thread Starter

VoodooMojo

Joined Nov 28, 2009
505
http://en.wikipedia.org/wiki/Cat's-whisker_detector

Does anyone have any experiences with the Cat's Whiskers that can be shared?

Was this the true beginning to the semiconductor-age?
It is certainly not as celebrated as the 1947 development of Bardeen, Brittan, and Shockley.

I have always taught that "the semiconductor diode was the single most important technological development in the history of mankind."
and
"the transistor was the single most revolutionary technological development in the history of mankind."

just one man's opinions of course.

I remember my father always scratching around on his to get the farm report. He refused to use the new fangled radio we had...


http://semiconductormuseum.com/Museum_Index.htm
 
KL7AJ

KL7AJ

Joined Nov 4, 2008
2,229
VoodooMojo said:
http://en.wikipedia.org/wiki/Cat's-whisker_detector

Does anyone have any experiences with the Cat's Whiskers that can be shared?

Was this the true beginning to the semiconductor-age?
It is certainly not as celebrated as the 1947 development of Bardeen, Brittan, and Shockley.

I have always taught that "the semiconductor diode was the single most important technological development in the history of mankind."
and
"the transistor was the single most revolutionary technological development in the history of mankind."

just one man's opinions of course.

I remember my father always scratching around on his to get the farm report. He refused to use the new fangled radio we had...


http://semiconductormuseum.com/Museum_Index.htm
Click to expand...
Certainly!

When I was a youth, eveyone was building crystal radios. The Galena crystal with a steel whisker was the standard method. Alternatives were the Gillette blue blade rasor and a piece of pencil lead.
(You can still get mounted galena crystals from www.midnightscience.com )

The cat's whisker was so sensitive because, unbeknownst to its early users, it is a HOT CARRIER DIODE!...basically NO forward voltage drop.

No question it was the first solid state device!


Eric
 
Wendy

Wendy

Joined Mar 24, 2008
23,421
But Shottky Diodes are, which are pretty much the same thing.

I read an article a long time ago that stated if you hunted on a natural germanium crystal it was possible to find two points that would be a transistor, though with low gain and really poor performance. I'm not sure I believe it, but it was a nice concept.
 
beenthere

beenthere

Joined Apr 20, 2004
15,819
The oxide coating to partially rustproof the blade worked the magic. It was easier for electrons to pass in one direction than the other. The blue coloration of the razor blades might be related to the oxide coating applied to weapons to give them some rust resistance.
 
JDT

JDT

Joined Feb 12, 2009
657
VoodooMojo said:
http://en.wikipedia.org/wiki/Cat's-whisker_detector
Was this the true beginning to the semiconductor-age?
It is certainly not as celebrated as the 1947 development of Bardeen, Brittan, and Shockley.
Click to expand...
Semiconductors research was going on long before this.

You may be interested to know, for example, that the LED was discovered in the mid 1920's by Oleg Vladimirovich Losev who:

"observed light emission from zinc oxide and silicon carbide crystal rectifier diodes used in radio receivers when a current was passed through them"

This is from a article in Nature Photonics April 2007 that published a copy of the Losev's original paper.

OK, that's your interesting fact for today!
 
VoodooMojo

Thread Starter

VoodooMojo

Joined Nov 28, 2009
505
JDT said:
Semiconductors research was going on long before this.

You may be interested to know, for example, that the LED was discovered in the mid 1920's by Oleg Vladimirovich Losev who:

"observed light emission from zinc oxide and silicon carbide crystal rectifier diodes used in radio receivers when a current was passed through them"

This is from a article in Nature Photonics April 2007 that published a copy of the Losev's original paper.

OK, that's your interesting fact for today!
Click to expand...

That is what prompted me to ask about what might be the beginning of the semiconductor-age.
The wiki link I posted stated that all this point contact stuff started before the vacuum tube. So, contrary to popular belief, the semiconductor preceded the tube?
http://en.wikipedia.org/wiki/Cat's-whisker_detector

My father always preached that Fleming and the like slowed us down technologically by steering the attention away from semiconductor development.
http://en.wikipedia.org/wiki/Fleming_valve

It wasn't until the space ship landed in New Mexico and the aliens needed to get back home. They took the sand and mixed it with aluminum from their spaceship and phosphorus they found at Carlsbad Caverns and made semiconductor diodes and transistors so they could repair the electronics onboard their ship. But they got caught and were interrogated and divulged the information to Bell Laboratories.
The preceding is not my belief, just mumbo-jumbo that makes for good bar-room banter. Although it is an interesting and entertaining concept.

History

The "point rectifier effect", as it was then called, was discovered by Ferdinand Braun, a German physicist and radio pioneer, in 1874 at the University of Würzburg. Based on this work G.W. Pickard developed the cat's whisker diode using a silicon crystal, which was patented in 1906. However, Bengali scientist Jagadish Chandra Bose may have been the first to use a semiconductor to rectify radio waves, applying for a patent on a galena detector in 1901.


Unamplified radio receivers, most of which were crystal radios, were the only way to receive radio signals during most of the wireless telegraphy era, which ended around 1920. Mineral detectors were largely superseded by vacuum tubes, invented in 1906, although the expense of tube receivers meant that full replacement took several decades. By the 1920s crystal radios were relegated to use by hobbyists and youth groups.


The point-contact Si detector was subsequently resurrected around World War II because of the military requirement for microwave radar. Vacuum tube detectors do not work at microwave frequencies. Even the semiconductor p-n junction detectors may not be fast enough compared to semiconductor point contact detectors because of minority carrier storage problem, and large capacitance if the area is not small enough.
 
Last edited:
KL7AJ

KL7AJ

Joined Nov 4, 2008
2,229
VoodooMojo said:
That is what prompted me to ask about what might be the beginning of the semiconductor-age.
The wiki link I posted stated that all this point contact stuff started before the vacuum tube. So, contrary to popular belief, the semiconductor preceded the tube?
http://en.wikipedia.org/wiki/Cat's-whisker_detector

My father always preached that Fleming and the like slowed us down technologically by steering the attention away from semiconductor development.
http://en.wikipedia.org/wiki/Fleming_valve

It wasn't until the space ship landed in New Mexico and the aliens needed to get back home. They took the sand and mixed it with aluminum from their spaceship and phosphorus they found at Carlsbad Caverns and made semiconductor diodes and transistors so they could repair the electronics onboard their ship. But they got caught and were interrogated and divulged the information to Bell Laboratories.
The preceding is not my belief, just mumbo-jumbo that makes for good bar-room banter. Although it is an interesting and entertaining concept.

History

The "point rectifier effect", as it was then called, was discovered by Ferdinand Braun, a German physicist and radio pioneer, in 1874 at the University of Würzburg. Based on this work G.W. Pickard developed the cat's whisker diode using a silicon crystal, which was patented in 1906. However, Bengali scientist Jagadish Chandra Bose may have been the first to use a semiconductor to rectify radio waves, applying for a patent on a galena detector in 1901.


Unamplified radio receivers, most of which were crystal radios, were the only way to receive radio signals during most of the wireless telegraphy era, which ended around 1920. Mineral detectors were largely superseded by vacuum tubes, invented in 1906, although the expense of tube receivers meant that full replacement took several decades. By the 1920s crystal radios were relegated to use by hobbyists and youth groups.


The point-contact Si detector was subsequently resurrected around World War II because of the military requirement for microwave radar. Vacuum tube detectors do not work at microwave frequencies. Even the semiconductor p-n junction detectors may not be fast enough compared to semiconductor point contact detectors because of minority carrier storage problem, and large capacitance if the area is not small enough.
Click to expand...

It's prpbably fair to say that tha vacuum tubes advanced faster than solid state devices because their operation was better understood. Electrons drifting through an enpty bottle is pretty straightforward and intuitive, whereas holes and lattices and energy states were still pretty exotic concepts even in the 1950s. People got predictable results with vacuum tubes, and pretty good performance could be had with some pretty crude manufacturing tolerances. Not so with solid state, of course!

Or to put it succinctly....the squeaky wheel gets the grease. :) Tubes just squeaked louder earlier in the game.

Eric
 
Wendy

Wendy

Joined Mar 24, 2008
23,421
For some applications tubes are still king. If you need high power RF that isn't too high in the band tubes just plain work better.

I suspect when they have a lunar output there will be the mother of all tubes sitting out in the open, doing its thing.
 
Wendy

Wendy

Joined Mar 24, 2008
23,421
Remove the glass envelop, it is not needed. Possibly use a solar array using sunlight to heat the cathode, it doesn't have to be electricity. You then have something that puts any FET or MOSFET to shame.
 
Last edited:
You must log in or register to reply here.
Thread starter Similar threads Forum Replies Date
tienk Where can i find the spice file of this relay? PCB Layout , EDA & Simulations 5
rambomhtri Where is all the leaded solder wire? Why is everything lead-free now? General Electronics Chat 92
askDIY Trying to test LM1875 circuit, don't know where to place voltage probes Test & Measurement 7
schmitt trigger Where have good-quality products gone? Off-Topic 56
R Metal crystal 'whisker' growth! Off-Topic 15
Similar threads
Where can i find the spice file of this relay?
Where is all the leaded solder wire? Why is everything lead-free now?
Trying to test LM1875 circuit, don't know where to place voltage probes
Where have good-quality products gone?
Metal crystal 'whisker' growth!

You May Also Like

Top