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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 80 to 100.
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Author: Ken FowlerDate: 16:17 23-04-08
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On 22-Apr-2008, Michael Black <et472@ncf.ca> 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.
> >
I started working on military surplus radios and consumer broadcast radios
in 1954, went to US Navy ET school in 1956, and spent a few years reparing
communications and radar equipment manufactured in the 1947 - 1960 era.
Other than the 1N21 and 1N23 diodes used in radar receivers, which I
believe were point-contact germanium devices, the first signal diodes I saw
were the 1N34 types used in an IFF decoder. They were relatively large
axial packages with a hexagonal body shape. All other places where a diode
was necessary, vacuum tubes were used for small signals and Selemium-oxide
plate rectifiers were used in power supplies. By 1959, when I went to
school on the AN/URC-32 SSB Transceiver, both germanium and silicon diodes
and transistors were in wide use in new military radio circuits. From my
experience, no silicon diodes were used at any time before 1950 in USN
military equipment. The first consumer transistorized radios I remember
were sometime around 1960. I wish I still had my Allied Radio Catalogs
from 1954 and later. You could buy a Raytheon CK721 transistor for
something like $3. I think the CK722 cost more. By 1965, you could buy
grab bags of transistors and diodes at Radio Shack for $3.
Good Memories,
Ken Fowler, KO6NO
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Author: John PopelishDate: 16:27 23-04-08
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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
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Author: John LarkinDate: 16:47 23-04-08
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On Wed, 23 Apr 2008 11:46:09 -0700 (PDT), Tom Bruhns <k7itm@msn.com>
wrote:
>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
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
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Author: John LarkinDate: 16:51 23-04-08
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On Wed, 23 Apr 2008 16:27:21 -0400, John Popelish <jpopelish@rica.net>
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
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Author: John FieldsDate: 18:03 23-04-08
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On Wed, 23 Apr 2008 07:52:46 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>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.
---
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
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Author: John FieldsDate: 18:08 23-04-08
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On Thu, 24 Apr 2008 00:58:28 +1000, "Phil Allison"
<philallison@tpg.com.au> 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
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Author: John PopelishDate: 18:39 23-04-08
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John Larkin wrote:
> On Wed, 23 Apr 2008 16:27:21 -0400, John Popelish <jpopelish@rica.net>
> 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.
Yes, interesting, but not very much like the characteristics
of 1N23.
--
Regards,
John Popelish
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Author: Tom BruhnsDate: 20:28 23-04-08
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On Apr 23, 1:27 pm, John Popelish <jpopel...@rica.net> 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.
>
> --
> Regards,
>
> John Popelish
HSMS-2850 is about 0.2V @ 1mA, but it also has a PIV rating of just 2
volts. Capacitance is considerably less than that CMMSH1-20, though.
I don't have any point-contact diodes to compare it with, but can tell
you that it's useful for detecting RF down to a bit below 100uV,
possibly less if you're careful with thermal potentials and the like,
or chop the signal.
Cheers,
Tom
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Author: John LarkinDate: 11:53 25-04-08
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On Wed, 23 Apr 2008 20:17:28 GMT, "Ken Fowler" <ko6no@yahoo.com>
wrote:
>
>On 22-Apr-2008, Michael Black <et472@ncf.ca> 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.
>> >
>
>I started working on military surplus radios and consumer broadcast radios
>in 1954, went to US Navy ET school in 1956, and spent a few years reparing
>communications and radar equipment manufactured in the 1947 - 1960 era.
>Other than the 1N21 and 1N23 diodes used in radar receivers, which I
>believe were point-contact germanium devices, the first signal diodes I saw
>were the 1N34 types used in an IFF decoder. They were relatively large
>axial packages with a hexagonal body shape. All other places where a diode
>was necessary, vacuum tubes were used for small signals and Selemium-oxide
>plate rectifiers were used in power supplies. By 1959, when I went to
>school on the AN/URC-32 SSB Transceiver, both germanium and silicon diodes
>and transistors were in wide use in new military radio circuits. From my
>experience, no silicon diodes were used at any time before 1950 in USN
>military equipment. The first consumer transistorized radios I remember
>were sometime around 1960. I wish I still had my Allied Radio Catalogs
>from 1954 and later. You could buy a Raytheon CK721 transistor for
>something like $3. I think the CK722 cost more. By 1965, you could buy
>grab bags of transistors and diodes at Radio Shack for $3.
>
>Good Memories,
>Ken Fowler, KO6NO
The 1N21 and 1N23 were actually silicon point-contact diodes. The
other common 1940's rectifier was copper oxide, used for small-signal
rectification, notably for the AC ranges of VOM's.
John
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Author: JosephKKDate: 19:39 26-04-08
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On Wed, 23 Apr 2008 02:09:10 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:
>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)
Not arguing that. Would that diode make a good microwave detector?
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Author: JosephKKDate: 19:42 26-04-08
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On Tue, 22 Apr 2008 21:04:37 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>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
Say what you will. I was playing with 1950's (or older) parts in the
1960's. All the datasheets back then said Ge. Compare proper
contemporaneous parts.
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Author: JosephKKDate: 19:52 26-04-08
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On Wed, 23 Apr 2008 02:20:37 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:
>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)
Two things, these are "modern" parts. Did the equivalent exist in the
1940's or 1950's? Do they make good microwave detector diodes? I
think not. Use time and use appropriate devices for comparison.
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Author: JosephKKDate: 20:04 26-04-08
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On Wed, 23 Apr 2008 17:28:36 -0700 (PDT), Tom Bruhns <k7itm@msn.com>
wrote:
>On Apr 23, 1:27 pm, John Popelish <jpopel...@rica.net> 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.
>>
>> --
>> Regards,
>>
>> John Popelish
>
>HSMS-2850 is about 0.2V @ 1mA, but it also has a PIV rating of just 2
>volts. Capacitance is considerably less than that CMMSH1-20, though.
>I don't have any point-contact diodes to compare it with, but can tell
>you that it's useful for detecting RF down to a bit below 100uV,
>possibly less if you're careful with thermal potentials and the like,
>or chop the signal.
>
>Cheers,
>Tom
I am getting a little tired so may blatting about modern parts as if
they were available in the 1940'sand 1950's. The question is "What
were the original parts made of?"
Newer implementations is, at best, a side issue.
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Author: JosephKKDate: 20:06 26-04-08
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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.
>
>JF
And what is the junction capacitance and does it make a good microwave
mixer?
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Author: John PopelishDate: 21:34 26-04-08
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JosephKK wrote:
> On Wed, 23 Apr 2008 17:28:36 -0700 (PDT), Tom Bruhns <k7itm@msn.com>
> wrote:
>> HSMS-2850 is about 0.2V @ 1mA, but it also has a PIV rating of just 2
>> volts. Capacitance is considerably less than that CMMSH1-20, though.
>> I don't have any point-contact diodes to compare it with, but can tell
>> you that it's useful for detecting RF down to a bit below 100uV,
>> possibly less if you're careful with thermal potentials and the like,
>> or chop the signal.
>>
>> Cheers,
>> Tom
>
> I am getting a little tired so may blatting about modern parts as if
> they were available in the 1940'sand 1950's. The question is "What
> were the original parts made of?"
>
> Newer implementations is, at best, a side issue.
Were germanium PN junction diodes of the period (or any
later period) good microwave detectors? I thought they were
pretty slow.
--
Regards,
John Popelish
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Author: John LarkinDate: 22:06 26-04-08
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On Sat, 26 Apr 2008 16:42:57 -0700, JosephKK <quiettechblue@yahoo.com>
wrote:
>On Tue, 22 Apr 2008 21:04:37 -0700, John Larkin
><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>
>>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
>
>Say what you will. I was playing with 1950's (or older) parts in the
>1960's. All the datasheets back then said Ge. Compare proper
>contemporaneous parts.
>
Well, I'm sure your memory is more accurate than my books and
datasheets.
John
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Author: John PopelishDate: 22:10 26-04-08
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John Larkin wrote:
> On Sat, 26 Apr 2008 16:42:57 -0700, JosephKK <quiettechblue@yahoo.com>
>> Say what you will. I was playing with 1950's (or older) parts in the
>> 1960's. All the datasheets back then said Ge. Compare proper
>> contemporaneous parts.
>>
>
> Well, I'm sure your memory is more accurate than my books and
> datasheets.
I found an oral history from someone who was involved in the
research at the time (Art Uhlir Jr.). It is a bit
scattered, but very close to this discussion:
http://semiconductormuseum.com/Transistors/BellLabs/OralHistories/Uhlir/Uhlir_Index.htm
Bottom of page 10 gets to the 1N23.
--
Regards,
John Popelish
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Author: Jeff LiebermannDate: 22:46 26-04-08
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Author: EeyoreDate: 06:27 27-04-08
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JosephKK wrote: John Larkin wrote:
> >
> >Your data point is dead on the point-contact Silicon diode curve.
> >
> >John
>
> Say what you will. I was playing with 1950's (or older) parts in the
> 1960's. All the datasheets back then said Ge. Compare proper
> contemporaneous parts.
Maybe they changed from Si to Ge ?
My IEE book on the subject says the early radar diodes were silicon though.
Graham
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Author: Phil AllisonDate: 08:42 27-04-08
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"Eeysore"
JosephKK
>
>> Say what you will. I was playing with 1950's (or older) parts in the
>> 1960's. All the datasheets back then said Ge. Compare proper
>> contemporaneous parts.
>
> Maybe they changed from Si to Ge ?
>
> My IEE book on the subject says the early radar diodes were silicon
> though.
** Wake up - you pathetic dope.
You are wasting your remaining life arguing with a bona-fide " flat earther
" here.
Stop now - or else you will fall right off the edge ... .. ... ... ...
.. .
T - hump . . .. ..
... Phil
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