On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF

On Mon, 21 Apr 2008 11:24:46 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF

Smart-ass ping-pong plonked... no redeeming social value ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

On Mon, 21 Apr 2008 11:24:46 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF


You mean facts, as opposed to second-hand rumors you think you
remember? Guilty as charged.

John

On Mon, 21 Apr 2008 14:04:18 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 11:24:46 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF


You mean facts, as opposed to second-hand rumors you think you
remember? Guilty as charged.

---
"and Maybe"

"Could have been"

"Or maybe"

are facts?

Maybe in your fantasy world, but to me it all sounds like conjecture.

The _fact_ is I originally commented to the OP that his quest might be
made easier by considering the 1N23 as a starting point for silicon
detectors, but then amended my original comment to reflect that the
first time I had contact with them was in the '50's, when I thought it
was new.

I guess, according to you, I was right in the first place.

Oh, well...

I guess your way is to clam up if you think you've made a mistake
unless someone calls you on it.

That's not my way. If I think I've made a mistake I own up to it as
soon as it looks questionable to me without waiting for anyone to prod
me into forced admission.

Your mileage certainly seems to vary.


BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?

Thank you ever so much...

JF

On Mon, 21 Apr 2008 18:23:40 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 14:04:18 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 11:24:46 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF


You mean facts, as opposed to second-hand rumors you think you
remember? Guilty as charged.

---
"and Maybe"

"Could have been"

"Or maybe"

are facts?

Certainly not. Those were conjectures on why you might have thought
that these parts were new in the 1950's. As if it matters.


Maybe in your fantasy world, but to me it all sounds like conjecture.

Those words do usually imply conjecture, yes.



The _fact_ is I originally commented to the OP that his quest might be
made easier by considering the 1N23 as a starting point for silicon
detectors, but then amended my original comment to reflect that the
first time I had contact with them was in the '50's, when I thought it
was new.

I guess, according to you, I was right in the first place.

If it's so important to you to be right, you might consider checking
facts before posting. But do whatever's fun.


Oh, well...

I guess your way is to clam up if you think you've made a mistake
unless someone calls you on it.

That's not my way. If I think I've made a mistake I own up to it as
soon as it looks questionable to me without waiting for anyone to prod
me into forced admission.

Your mileage certainly seems to vary.


BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?

Nope, too much work. The books are widely available.

John

On Mon, 21 Apr 2008 17:18:02 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 18:23:40 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 14:04:18 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 11:24:46 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 07:58:29 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 09:25:01 -0500, John Fields
wrote:

On Sun, 20 Apr 2008 19:38:28 -0700, John Larkin
m wrote:

On Sun, 20 Apr 2008 18:29:32 -0500, John Fields
wrote:
On Sun, 20

Cite?

JF

MIT RadLab books, volume 15, "Crystal Rectifiers", appendix D,
published in 1948.

What is the citation for your statement that "The 1N23 didn't appear
until the '50's, I believe." ?

John

---
Working with them At Loral Electronics in New York and being told that
they were new, as I recall.

JF

There were 1N23A's B's, C's, and maybe D's. 1N23, A and B were wartime
parts. Could have been C+ they were talking about. Or maybe they were
just wrong.

---
Typical Larkinese...

JF


You mean facts, as opposed to second-hand rumors you think you
remember? Guilty as charged.

---
"and Maybe"

"Could have been"

"Or maybe"

are facts?

Certainly not. Those were conjectures on why you might have thought
that these parts were new in the 1950's. As if it matters.
---
Certainly seems to matter enough to you to keep posting about it.
---

Maybe in your fantasy world, but to me it all sounds like conjecture.

Those words do usually imply conjecture, yes.


The _fact_ is I originally commented to the OP that his quest might be
made easier by considering the 1N23 as a starting point for silicon
detectors, but then amended my original comment to reflect that the
first time I had contact with them was in the '50's, when I thought it
was new.

I guess, according to you, I was right in the first place.

If it's so important to you to be right, you might consider checking
facts before posting. But do whatever's fun.

---
I am.
---

Oh, well...

I guess your way is to clam up if you think you've made a mistake
unless someone calls you on it.

That's not my way. If I think I've made a mistake I own up to it as
soon as it looks questionable to me without waiting for anyone to prod
me into forced admission.

Your mileage certainly seems to vary.


BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?

Nope, too much work. The books are widely available.

---
Geez, thanks John. That's just about what I expected.

JF

John Fields wrote:

BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?


John, you missed the note at the top of that page:

Note: These volumes are only accessable on site at Jefferson Lab.


--
http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

On Tue, 22 Apr 2008 12:22:58 -0400, "Michael A. Terrell"
wrote:


John Fields wrote:

BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?


John, you missed the note at the top of that page:

Note: These volumes are only accessable on site at Jefferson Lab.

Jlab (used to be CEBAF) has a 1/4 mile racetrack electron accelerator,
pumped by klystrons driving cool shiny superconductive cavities with
megavolt-per-meter fields and Q's like 1e8 or something. Their site
has some interesting stuff. We did the electronics that measures all
the liquid helium temperatures and levels, and the microsteppers that
tume the cavities. That was probably the last major CAMAC installation
anywhere.

John

On Tue, 22 Apr 2008 12:22:58 -0400, "Michael A. Terrell"
wrote:


John Fields wrote:

BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?


John, you missed the note at the top of that page:

Note: These volumes are only accessable on site at Jefferson Lab.

---
Right. Thanks, :-)


JF

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

John Fields wrote:

On Tue, 22 Apr 2008 12:22:58 -0400, "Michael A. Terrell"
wrote:


John Fields wrote:

BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?


John, you missed the note at the top of that page:

Note: These volumes are only accessable on site at Jefferson Lab.

---
Right. Thanks, :-)

JF


Talk about greed!!

http://www.artechhouse.com/default.a...nent=SA&State=
Price $ 403.00 USD

--
http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

John Larkin wrote:

On Tue, 22 Apr 2008 12:22:58 -0400, "Michael A. Terrell"
wrote:


John Fields wrote:

BTW, for some reason I'm prohibited from accessing the Rad Lab series
via:

http://www.jlab.org/ir/MITSeries.html

so would you be so kind as to post the text referring explicitly to
the 1N23 and relevant deployment dating?


John, you missed the note at the top of that page:

Note: These volumes are only accessable on site at Jefferson Lab.

Jlab (used to be CEBAF) has a 1/4 mile racetrack electron accelerator,
pumped by klystrons driving cool shiny superconductive cavities with
megavolt-per-meter fields and Q's like 1e8 or something. Their site
has some interesting stuff. We did the electronics that measures all
the liquid helium temperatures and levels, and the microsteppers that
tume the cavities. That was probably the last major CAMAC installation
anywhere.


That sounds like a great set for a Sci-Fi movie. ;-)


--
http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

"Michael A. Terrell" wrote in message
...
Talk about greed!!
http://www.artechhouse.com/default.a...nent=SA&State=
Price $ 403.00 USD

Artech has never been cheap. :-) At this price, I think they figure they're
appealing mainly to University technical libraries and perhaps some larger
companies' internal corporate libraries... or perhaps they're thinking the
market for such historical documents is quite limited, thus "necessitating"
the higher price to cover their costs?

On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns
wrote:

On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

Just checking the footnotes in the radlab book, it looks like most of
the serious theorizing (ie, stuff that worked) was published between
1939 and 1942, "about 1940" by my standards. Potential barrier
diagrams and Fermi levels and such were in books published in 1940.
Mott and Schottky seem to have published the first non-silly diode
theory stuff (non-backwards!) in 1939 and 1940. This got a lot more
serious between 1940 and 1943 as MIT poured in money and talent.

John

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

---
John, I must say you're simply amazing!

Being able to postdict the butterfly effect is a gift few of us have.

JF

On Tue, 22 Apr 2008 16:03:15 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns
wrote:

On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

Just checking the footnotes in the radlab book, it looks like most of
the serious theorizing (ie, stuff that worked) was published between
1939 and 1942, "about 1940" by my standards. Potential barrier
diagrams and Fermi levels and such were in books published in 1940.
Mott and Schottky seem to have published the first non-silly diode
theory stuff (non-backwards!) in 1939 and 1940. This got a lot more
serious between 1940 and 1943 as MIT poured in money and talent.

---
Talent, maybe, but where do you think the money was coming from?

Hardly MIT, if their mandate was, as you state:

...."to develop radar to win the war."

JF

On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK
wrote:

On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey
wrote:

On 4/20/08 11:26 AM, in article ,
"JosephKK" wrote:

On Sat, 12 Apr 2008 11:29:18 -0500, John Fields
wrote:

On Sat, 12 Apr 2008 11:24:19 -0500, John Fields
wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, "ronwer"
wrote:

Hi!

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

What I would be interested in is as follows:

-type numbers of the diodes

---
1N23 is a good place to start.

---
Oops... brain fart.

The 1N23 didn't appear until the '50's, I believe.

JF

Not only that it was germanium not silicon.

Do you have a solid reference for that? "Credible" references I found said
they were silicon.


The most conclusive evidence i know of, is someone here who actually
put one to test and the result was germanium. A heck of a lot of
"official" or "authoritative" records are pure fertilizer.

What test?

John

V(f) @ 1 mA. Result 180 mV. Thus Ge, not Si.

On Mon, 21 Apr 2008 09:28:11 -0500, John Fields
wrote:

On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK
wrote:

On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey
wrote:

Do you have a solid reference for that? "Credible" references I found said
they were silicon.


The most conclusive evidence i know of, is someone here who actually
put one to test and the result was germanium. A heck of a lot of
"official" or "authoritative" records are pure fertilizer.

---
Can you spell "Schottky?"

JF

Certainly. 1N23s that i had were Ge also. Lost them on some move.

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

In article , JosephKK wrote:
On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
wrote:

On 21 Apr 2008 03:03:32 GMT, JosephKK wrote:

On 20 Apr 2008 13:59:36 -0700, Don Bowey wrote:

Do you have a solid reference for that? "Credible" references I found
said they were silicon.

The most conclusive evidence i know of, is someone here who actually
put one to test and the result was germanium. A heck of a lot of
"official" or "authoritative" records are pure fertilizer.

What test?

V(f) @ 1 mA. Result 180 mV. Thus Ge, not Si.

I have seen silicon schottky diodes that drop about .3 volt at 1 amp.

- Don Klipstein )

In article , JosephKK wrote:
On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

I am on a temporary setup now that does not have Acrobat, but I somewhat
remember Vishay-IR STPS1L30UPBF or 1N5818 dropping maybe .35 volt at 1
amp. These are 30 volt 1 amp Schottky rectifiers.

- Don Klipstein )

On Tue, 22 Apr 2008 18:17:10 -0700, JosephKK
wrote:

On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
wrote:

On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK
wrote:

On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey
wrote:

On 4/20/08 11:26 AM, in article ,
"JosephKK" wrote:

On Sat, 12 Apr 2008 11:29:18 -0500, John Fields
wrote:

On Sat, 12 Apr 2008 11:24:19 -0500, John Fields
wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, "ronwer"
wrote:

Hi!

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

What I would be interested in is as follows:

-type numbers of the diodes

---
1N23 is a good place to start.

---
Oops... brain fart.

The 1N23 didn't appear until the '50's, I believe.

JF

Not only that it was germanium not silicon.

Do you have a solid reference for that? "Credible" references I found said
they were silicon.


The most conclusive evidence i know of, is someone here who actually
put one to test and the result was germanium. A heck of a lot of
"official" or "authoritative" records are pure fertilizer.

What test?

John

V(f) @ 1 mA. Result 180 mV. Thus Ge, not Si.


Here are some curves from the RadLab book:

ftp://66.117.156.8/RadLabDiodes.JPG

ftp://66.117.156.8/RadDiode2.JPG

Your data point is dead on the point-contact Silicon diode curve.

John

On Tue, 22 Apr 2008 19:02:19 -0500, John Fields
wrote:

On Tue, 22 Apr 2008 16:03:15 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns
wrote:

On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

Just checking the footnotes in the radlab book, it looks like most of
the serious theorizing (ie, stuff that worked) was published between
1939 and 1942, "about 1940" by my standards. Potential barrier
diagrams and Fermi levels and such were in books published in 1940.
Mott and Schottky seem to have published the first non-silly diode
theory stuff (non-backwards!) in 1939 and 1940. This got a lot more
serious between 1940 and 1943 as MIT poured in money and talent.

---
Talent, maybe, but where do you think the money was coming from?

Hardly MIT, if their mandate was, as you state:

..."to develop radar to win the war."

JF

A couple of fascinating books are Buderi's "The Invention That Changed
The World" and Conant's "Tuxedo Park", both about the history of
microwave radar, and where the money came from.

Also Bowen's "Radar Days" and the Brit story of HF radar, "Three Steps
To Victory" by Sir Robert Watson-Watt, who probably saved England from
the Luftwaffe.

John

On Tue, 22 Apr 2008 18:55:18 -0500, John Fields
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

---
John, I must say you're simply amazing!

Being able to postdict the butterfly effect is a gift few of us have.

JF

One of the MIT books says that "a semiconductor triode should be
possible." But that wasn't their mandate. The RadLab was disbanded in
late 1945.

John

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

This is a silicon point-contact diode, essentially the same as the
WWII parts, expect that they get to use modern, very pure silicon:

http://www.micrometrics.com/pdfs/PC_SXBandMixer.pdf

Skyworks makes some very low capacitance (below 0.5 pF) schottkies
that are similar.


This is 300 mV *max* at 100 mA, so should be down there. I think the
schottky curve is sorta similar to the silicon PN curve, which is 60
mV per decade of current.

http://www.centralsemi.com/PDFs/products/CMHSH5-2L.PDF

I posted some WWII diode curves elsewhere, well under 200 mV at 1 mA.

Gee.

John

"JosephKKK Lunatic & Congenital LIAR "

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.


** Examples tested:

BAT46 = 0.261 V @ 1mA

MBR745 = 0.194 V @ 1mA

For comparison

AAZ15 (Ge) = 0.230 V @ 1 mA



The 1N23 ( Silicon point contact) is 0.25 V @ 1mA

http://pdf1.alldatasheet.net/datashe.../ETC/1N23.html



....... Phil

Rich Grise inscribed thus:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yes ! I have some devices that were made in the mid to late 40's.

Also if I can find them I have some pre war point contact detectors that
have screw terminals on the ends.

Baron.

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

---
I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.

JF

On Wed, 23 Apr 2008 08:51:25 -0500, John Fields
wrote:

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

---
I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.

---
Just to make sure it wasn't an anomaly, I measured 10 more and here's
what I got:

If Vf
mA V
-------+-------+
1.000 0.1495
1.000 0.1350
1.000 0.1525
1.000 0.1344
1.000 0.1495
1.000 0.1355
1.000 0.1510
1.000 0.1532
1.000 0.1496
1.000 0.1370


The equipment was set up like this:



+-------[WAVETEK 27XT]---[10k]---+----------+
|+ |A |+
[HP 6216A] [DUT] [FLUKE 8060A]
|- | |-
+--------------------------------+----------+


The 8060A draws 25µA on the 2 volt range, so the current out of the
6216A was set to 1.025mA for every reading in order to force 1.000mA
through the 1N5817s.

Turns out the power supply was impossible to adjust spot on, so I put
the 10k resistor in there to give me fewer µA per degree of rotation
of the knob. Worked great.

JF

On Wed, 23 Apr 2008 09:50:13 -0500, John Fields
wrote:

On Wed, 23 Apr 2008 08:51:25 -0500, John Fields
wrote:

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

---
I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.

---
Just to make sure it wasn't an anomaly, I measured 10 more and here's
what I got:

If Vf
mA V
-------+-------+
1.000 0.1495
1.000 0.1350
1.000 0.1525
1.000 0.1344
1.000 0.1495
1.000 0.1355
1.000 0.1510
1.000 0.1532
1.000 0.1496
1.000 0.1370


The equipment was set up like this:



+-------[WAVETEK 27XT]---[10k]---+----------+
|+ |A |+
[HP 6216A] [DUT] [FLUKE 8060A]
|- | |-
+--------------------------------+----------+


The 8060A draws 25µA on the 2 volt range, so the current out of the
6216A was set to 1.025mA for every reading in order to force 1.000mA
through the 1N5817s.

Turns out the power supply was impossible to adjust spot on, so I put
the 10k resistor in there to give me fewer µA per degree of rotation
of the knob. Worked great.

JF

Most DVM's seem to output 1 mA on the diode-test range. I don't know
how much of a convention that is. They do seem to disagree on how much
voltage they'll indicate: some display the Vf of an LED, some say open
or overload or whatever.

John

"John Fields"

I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.


** But you well knew that Motorola describe them as having " Extremely low
Vf " - now didn't you ??

http://www.onsemi.com/pub_link/Collateral/1N5817-D.PDF


BTW:

how hot did you make it get first ?


..... Phil

On Apr 22, 4:03 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns
wrote:



On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

Just checking the footnotes in the radlab book, it looks like most of
the serious theorizing (ie, stuff that worked) was published between
1939 and 1942, "about 1940" by my standards. Potential barrier
diagrams and Fermi levels and such were in books published in 1940.
Mott and Schottky seem to have published the first non-silly diode
theory stuff (non-backwards!) in 1939 and 1940. This got a lot more
serious between 1940 and 1943 as MIT poured in money and talent.

John

Thanks for the references, John. Sounds like Buderi, who certainly
had access to all that, might have put it in somewhat different light
than he did, perhaps something along the lines of, "though much
theoretical work had been done by 1940, it remained to discover how to
apply it in practice." He does make it clear that researchers all the
way up through development of the transistor didn't fully appreciate
what they could do with potential barrier diagrams and Fermi levels
and the like. As I scan through the book, I see multiple references
to events over several years where there was clear puzzlement, limited
understanding, and/or disagreement about what was going on in observed
effects around semiconductors. The serious search for a solid-state
amplifier (based on semiconductor materials) was started apparently at
least by 1936 at Bell Labs, and I suppose it was there and at a very
small number of universities where much of the published work you cite
was begun or carried out. Too bad that it's a bit late to be asking
the people actually involved in the work! (Wish I'd had the foresight
and time to ask my uncle more about the work he did at RadLab. :-( )

Cheers,
Tom

On Tue, 22 Apr 2008 21:40:49 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

This is a silicon point-contact diode, essentially the same as the
WWII parts, expect that they get to use modern, very pure silicon:

http://www.micrometrics.com/pdfs/PC_SXBandMixer.pdf

Skyworks makes some very low capacitance (below 0.5 pF) schottkies
that are similar.


This is 300 mV *max* at 100 mA, so should be down there. I think the
schottky curve is sorta similar to the silicon PN curve, which is 60
mV per decade of current.

http://www.centralsemi.com/PDFs/products/CMHSH5-2L.PDF

I posted some WWII diode curves elsewhere, well under 200 mV at 1 mA.

Gee.

John



Central CMMSH1-20 is a really tiny, about 1206 size, 1 amp 20 volt
schottky, great for small buck switchers; measures 201 mV at 1 mA. But
it's 280 pF!

John

John Larkin wrote:

Central CMMSH1-20 is a really tiny, about 1206 size, 1 amp 20 volt
schottky, great for small buck switchers; measures 201 mV at 1 mA. But
it's 280 pF!

I think if you do a Google search for "zero bias diode" you
will find things a lot more similar to 1N23 in electrical
characteristics.

--
Regards,

John Popelish

On Wed, 23 Apr 2008 11:46:09 -0700 (PDT), Tom Bruhns
wrote:

On Apr 22, 4:03 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns
wrote:



On Apr 22, 1:42 pm, John Larkin
wrote:
On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:
On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

I'd question that "was well understood" part. The description in the
Buderi book makes it pretty clear that before 1940, people working
with semiconductors (key being at Bell Labs) didn't have a very deep
understanding of what was going on. It was only in late '39 and 40
that they got serious ideas that they could actually control what was
an essentially empirically-understood phenomenon by changing the
amount and type of impurity. The description of things going on then
as "increasingly curious properties" of silicon doesn't seem to fit
very well with "well understood." But maybe Buderi didn't do a very
good job documenting that particular work, and missed the depth to
which the phenomena were understood.

Cheers,
Tom

Just checking the footnotes in the radlab book, it looks like most of
the serious theorizing (ie, stuff that worked) was published between
1939 and 1942, "about 1940" by my standards. Potential barrier
diagrams and Fermi levels and such were in books published in 1940.
Mott and Schottky seem to have published the first non-silly diode
theory stuff (non-backwards!) in 1939 and 1940. This got a lot more
serious between 1940 and 1943 as MIT poured in money and talent.

John

Thanks for the references, John. Sounds like Buderi, who certainly
had access to all that, might have put it in somewhat different light
than he did, perhaps something along the lines of, "though much
theoretical work had been done by 1940, it remained to discover how to
apply it in practice." He does make it clear that researchers all the
way up through development of the transistor didn't fully appreciate
what they could do with potential barrier diagrams and Fermi levels
and the like. As I scan through the book, I see multiple references
to events over several years where there was clear puzzlement, limited
understanding, and/or disagreement about what was going on in observed
effects around semiconductors. The serious search for a solid-state
amplifier (based on semiconductor materials) was started apparently at
least by 1936 at Bell Labs, and I suppose it was there and at a very
small number of universities where much of the published work you cite
was begun or carried out. Too bad that it's a bit late to be asking
the people actually involved in the work! (Wish I'd had the foresight
and time to ask my uncle more about the work he did at RadLab. :-( )

Cheers,
Tom


The radlab boys observed a number of interesting things that they
didn't have the time to pursue. One was negative resistance in diodes,
and another was diode mixers that had signal power gain, the precursor
to the parametric amplifier. Tunneling was known, too, a long time
before Esaki discovered the tunnel diode.

All that is in one book out of 27. In about 5 years, these guys
invented modern electronics.

John

On Wed, 23 Apr 2008 16:27:21 -0400, John Popelish
wrote:

John Larkin wrote:

Central CMMSH1-20 is a really tiny, about 1206 size, 1 amp 20 volt
schottky, great for small buck switchers; measures 201 mV at 1 mA. But
it's 280 pF!

I think if you do a Google search for "zero bias diode" you
will find things a lot more similar to 1N23 in electrical
characteristics.

"Back diode" is interesting, too. They are, to my knowledge, the only
germanium diodes made using an ic-type mask process, and about the
only Ge diodes still made at all, except for photodiodes of course.
They are still the best microwave detectors.

John

On Wed, 23 Apr 2008 07:52:46 -0700, John Larkin
wrote:

On Wed, 23 Apr 2008 09:50:13 -0500, John Fields
wrote:

On Wed, 23 Apr 2008 08:51:25 -0500, John Fields
wrote:

On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK
wrote:

On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
wrote:

On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise wrote:

On Sat, 12 Apr 2008 17:51:10 +0200, ronwer wrote:

I am doing a study into the early use of silicon diodes in radar and
communication equipment during the Second World War.

Did they even _have_ silicon diodes in WWII? I remember when they
announced the first transistor, some time in the early 1950's.

Thanks,
Rich

Yup. Most of the WWII radar diodes were silicon point-contact types,
Schottky diodes actually. The best 1943-vintage mixer parts were about
as good as any packaged schottky you can buy today... 0.2 Vf, 0.2 pF,
decent noise figures to 30 GHz.

The point-contact transistor was invented at Bell Labs in 1947. Most
of the relevant semiconductor theory - bandgaps, hole/electron
conduction, doping - was well understood by about 1940. The RadLab
guys didn't develop a PN-junction diode or the transistor because
their mandate was to develop radar to win the war.

John

Gee, John. Where do you get schottky diodes with V(f) below 0.2 V at
I(f) of 1 mA? All the ones i could find were over 0.33 V and mostly
0.4 to 0.5 V.

---
I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.

---
Just to make sure it wasn't an anomaly, I measured 10 more and here's
what I got:

If Vf
mA V
-------+-------+
1.000 0.1495
1.000 0.1350
1.000 0.1525
1.000 0.1344
1.000 0.1495
1.000 0.1355
1.000 0.1510
1.000 0.1532
1.000 0.1496
1.000 0.1370


The equipment was set up like this:



+-------[WAVETEK 27XT]---[10k]---+----------+
|+ |A |+
[HP 6216A] [DUT] [FLUKE 8060A]
|- | |-
+--------------------------------+----------+


The 8060A draws 25µA on the 2 volt range, so the current out of the
6216A was set to 1.025mA for every reading in order to force 1.000mA
through the 1N5817s.

Turns out the power supply was impossible to adjust spot on, so I put
the 10k resistor in there to give me fewer µA per degree of rotation
of the knob. Worked great.

JF

Most DVM's seem to output 1 mA on the diode-test range.

---
Into a short.
---

don't know how much of a convention that is.

---
I have 5, and on the DIODE TEST function they put out:

EMCO DMR3250 1.3229 mA

SPECO DMR2500 1.2045 mA

WAVETEK DM5XL 1.0387 mA

WAVETEK 27XT 1.0098 mA

FLUKE 8060A 0.943 mA

So it seems to be pretty conventional.
---

They do seem to disagree on how much
voltage they'll indicate: some display the Vf of an LED, some say open
or overload or whatever.

---
Depends on the Vf of the LED, I suspect. All of mine display the
voltage drop of the DUT, whether it's a resistor or a diode or
whatever, and display overload when the voltage gets to be 1.999V.

Here are the results of an experiment I just finished running:


+-------------------------------------+
| |
+--[SOURCE]--------[R]--------[LOAD]--+

VOLTS OHMS MILLIAMPS

DMR3520 0.123 0 1.3229
2.000 12300 0.1773

DMR2500 0.100 0 1.2045
2.000 1913 0.616

DM5XL 0.106 0 1.0387
2.000 6072 0.3273

27XT 0.101 0 1.0098
2.000 5423 0.3662

8060A 0.095 0 0.943
2.000 2056 0.934

The series resistance was a Clarostat 240C decade resistor box, and
for the first four entries the load was the Fluke 8060A. In the last
one it was the Wavetek 27XT.

The test was run by measuring the current from the source (the meter
switched to the DIODE TEST function), recording it, then recording the
voltage indicated on the source's display, then switching in
resistance until the source's display indicated overload.

Interesting to note that the Fluke has an almost constant current
source feeding the DUT, while none of the others do.

JF

On Thu, 24 Apr 2008 00:58:28 +1000, "Phil Allison"
wrote:


"John Fields"

I just pulled a random 1N5817 out of stock, put 1.000 milliamps
through it and measured 0.1383 volts across it.


** But you well knew that Motorola describe them as having " Extremely low
Vf " - now didn't you ??

http://www.onsemi.com/pub_link/Collateral/1N5817-D.PDF

---
Actually, I didn't, but thanks for the clue.
---


BTW:

how hot did you make it get first ?

---
Well, I showed it my penis...

JF