KBr Crystal Amplifier - Electronic Circuits Projects Diagrams Free

tansis · 7th July 2004, 11:23 PM

It's been a few weeks since my last bout of cranial anarchy so I think another brain teaser is in order, well more of a quest this time.

Delving into the history of the transistor and semi-conductor theory one will find repeated references to the work of Robert Pohl and Rudolph Hilsch. Now back in 1938 they claim to have created a three electrode (Potassium Bromide) crystal amplifier, with a reputed current gain of 100 to 1 and some rather curious operating properties, however its performance made it unsuitable for many uses such as RF and audio amplifiication, so it was banished to history, well almost.

What I would like to know is..
Has anyone managed to build a duplicate device in more recent times?

Russlk · 9th July 2004, 04:55 AM

Is there any record of how they did it? I once tried to make a transistor by adding a 2nd point contact to a 1N34 crystal diode, but I didn't know what I was doing and it did not work.

Sebi · 9th July 2004, 12:42 PM

Just for curiosity...

tansis · 9th July 2004, 07:46 PM

Have yet to find any detailed info myself, I intend to have an hour or two trawling through the Patent Office website some time over the weekend.

Sebi has found a remarkable piece of history from the Bell Telephone Laboratories, a copy of the orginal notes for the first transistor dated December 1947

Want to make your own transistors ?, try this link for inspiration...
http://www.mindspring.com/~pfriedr/b...ry/gallery.htm

It takes a while to load but the images at the bottom/end of the page are fascinating.

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7th July 2004, 11:23 PM	(permalink)
tansis	KBr Crystal Amplifier It's been a few weeks since my last bout of cranial anarchy so I think another brain teaser is in order, well more of a quest this time. Delving into the history of the transistor and semi-conductor theory one will find repeated references to the work of Robert Pohl and Rudolph Hilsch. Now back in 1938 they claim to have created a three electrode (Potassium Bromide) crystal amplifier, with a reputed current gain of 100 to 1 and some rather curious operating properties, however its performance made it unsuitable for many uses such as RF and audio amplifiication, so it was banished to history, well almost. What I would like to know is.. Has anyone managed to build a duplicate device in more recent times?

9th July 2004, 04:55 AM	(permalink)
Russlk	Is there any record of how they did it? I once tried to make a transistor by adding a 2nd point contact to a 1N34 crystal diode, but I didn't know what I was doing and it did not work. __________________ see my website: www.geocities.com/russlk

9th July 2004, 07:46 PM	(permalink)
tansis	Have yet to find any detailed info myself, I intend to have an hour or two trawling through the Patent Office website some time over the weekend. Sebi has found a remarkable piece of history from the Bell Telephone Laboratories, a copy of the orginal notes for the first transistor dated December 1947 Want to make your own transistors ?, try this link for inspiration... http://www.mindspring.com/~pfriedr/b...ry/gallery.htm It takes a while to load but the images at the bottom/end of the page are fascinating.