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Sci.Electronics.Basics -> Si-diodes in Second World War radar & Communication equipment
There are 103 messages in this thread.
You are currently looking at messages 60 to 80.
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Author: John FieldsDate: 19:55 22-04-08
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On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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
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Author: John FieldsDate: 20:02 22-04-08
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On Tue, 22 Apr 2008 16:03:15 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns <k7itm@msn.com>
>wrote:
>
>>On Apr 22, 1:42 pm, John Larkin
>><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>>> On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <r...@example.net>
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
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Author: JosephKKDate: 21:17 22-04-08
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On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK <quiettechblue@yahoo.com>
>wrote:
>
>>On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey <dbowey@comcast.net>
>>wrote:
>>
>>>On 4/20/08 11:26 AM, in article am2n04hciv1c0trs9vmfala4pf78ic80nb@4ax.com,
>>>"JosephKK" <quiettechblue@yahoo.com> wrote:
>>>
>>>> On Sat, 12 Apr 2008 11:29:18 -0500, John Fields
>>>> <jfields@austininstruments.com> wrote:
>>>>
>>>>> On Sat, 12 Apr 2008 11:24:19 -0500, John Fields
>>>>> <jfields@austininstruments.com> wrote:
>>>>>
>>>>>> On Sat, 12 Apr 2008 17:51:10 +0200, "ronwer"
>>>>>> <neo.dymium.removethisfirst@dontwantspam.yahoo.com>
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.
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Author: JosephKKDate: 21:19 22-04-08
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On Mon, 21 Apr 2008 09:28:11 -0500, John Fields
<jfields@austininstruments.com> wrote:
>On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK <quiettechblue@yahoo.com>
>wrote:
>
>>On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey <dbowey@comcast.net>
>>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.
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Author: JosephKKDate: 22:00 22-04-08
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On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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.
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Author: Don KlipsteinDate: 22:09 22-04-08
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In article <pd3t04l5i3gck6c4r87f0a51e2qr5hia0e@4ax.com>, JosephKK wrote:
>On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On 21 Apr 2008 03:03:32 GMT, JosephKK <quiettechblue@yahoo.com> wrote:
>>
>>>On 20 Apr 2008 13:59:36 -0700, Don Bowey <dbowey@comcast.net>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 (don@misty.com)
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Author: Don KlipsteinDate: 22:20 22-04-08
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In article <hr5t04l9866fsp3r3s3sqgjcasco3fv1gr@4ax.com>, JosephKK wrote:
>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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 (don@misty.com)
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Author: John LarkinDate: 00:04 23-04-08
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On Tue, 22 Apr 2008 18:17:10 -0700, JosephKK <quiettechblue@yahoo.com>
wrote:
>On Sun, 20 Apr 2008 20:45:08 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Mon, 21 Apr 2008 03:03:32 GMT, JosephKK <quiettechblue@yahoo.com>
>>wrote:
>>
>>>On Sun, 20 Apr 2008 13:59:36 -0700, Don Bowey <dbowey@comcast.net>
>>>wrote:
>>>
>>>>On 4/20/08 11:26 AM, in article
am2n04hciv1c0trs9vmfala4pf78ic80nb@4ax.com,
>>>>"JosephKK" <quiettechblue@yahoo.com> wrote:
>>>>
>>>>> On Sat, 12 Apr 2008 11:29:18 -0500, John Fields
>>>>> <jfields@austininstruments.com> wrote:
>>>>>
>>>>>> On Sat, 12 Apr 2008 11:24:19 -0500, John Fields
>>>>>> <jfields@austininstruments.com> wrote:
>>>>>>
>>>>>>> On Sat, 12 Apr 2008 17:51:10 +0200, "ronwer"
>>>>>>> <neo.dymium.removethisfirst@dontwantspam.yahoo.com>
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
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Author: John LarkinDate: 00:12 23-04-08
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On Tue, 22 Apr 2008 19:02:19 -0500, John Fields
<jfields@austininstruments.com> wrote:
>On Tue, 22 Apr 2008 16:03:15 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns <k7itm@msn.com>
>>wrote:
>>
>>>On Apr 22, 1:42 pm, John Larkin
>>><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>>>> On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <r...@example.net>
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
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Author: John LarkinDate: 00:16 23-04-08
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On Tue, 22 Apr 2008 18:55:18 -0500, John Fields
<jfields@austininstruments.com> wrote:
>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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
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Author: John LarkinDate: 00:40 23-04-08
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On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK <quiettechblue@yahoo.com>
wrote:
>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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
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Author: Phil AllisonDate: 00:53 23-04-08
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"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/datasheet-pdf/view/121948/ETC/1N23.html
...... Phil
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Author: BaronDate: 06:10 23-04-08
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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.
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Author: John FieldsDate: 09:51 23-04-08
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On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK <quiettechblue@yahoo.com>
wrote:
>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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
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Author: EeyoreDate: 10:28 23-04-08
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John Fields wrote:
> JosephKK wrote:
> >
> >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.
Sounds about right.
I have a book here about the develpoment of active devices for radar and it's
quite unambiguous about silicon being used for microwave diodes. The early
work was actually done by GEC and BTH of the UK in conjuction with military
R&D.
As ever the Americans refined the manufacturing process. The early ones were
virtually 'hand made'.
Graham
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Author: John FieldsDate: 10:50 23-04-08
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On Wed, 23 Apr 2008 08:51:25 -0500, John Fields
<jfields@austininstruments.com> wrote:
>On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK <quiettechblue@yahoo.com>
>wrote:
>
>>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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 25ľA 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 ľA per degree of rotation
of the knob. Worked great.
JF
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Author: John LarkinDate: 10:52 23-04-08
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On Wed, 23 Apr 2008 09:50:13 -0500, John Fields
<jfields@austininstruments.com> wrote:
>On Wed, 23 Apr 2008 08:51:25 -0500, John Fields
><jfields@austininstruments.com> wrote:
>
>>On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK <quiettechblue@yahoo.com>
>>wrote:
>>
>>>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>>>
>>>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net>
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 25ľA 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 ľA 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
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Author: Phil AllisonDate: 10:58 23-04-08
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"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
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Author: Tom BruhnsDate: 14:46 23-04-08
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On Apr 22, 4:03 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Tue, 22 Apr 2008 14:22:47 -0700 (PDT), Tom Bruhns <k7...@msn.com>
> wrote:
>
>
>
> >On Apr 22, 1:42 pm, John Larkin
> ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> >> On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <r...@example.net>
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
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Author: John LarkinDate: 15:58 23-04-08
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On Tue, 22 Apr 2008 21:40:49 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 22 Apr 2008 19:00:35 -0700, JosephKK <quiettechblue@yahoo.com>
>wrote:
>
>>On Tue, 22 Apr 2008 13:42:10 -0700, John Larkin
>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>On Tue, 22 Apr 2008 20:19:49 GMT, Rich Grise <rich@example.net> 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
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