Reply by Michael A. Terrell●September 13, 20132013-09-13
Spehro Pefhany wrote:
>
> There a company with all kinds of cool stuff called Meshna?? or
> something like that.
John Meshna, long gone. Both the owner and the surplus store.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
Reply by Phil Hobbs●August 30, 20132013-08-30
On 08/29/2013 11:57 PM, Greegor wrote:
>> GPD is a pretty good outfit. They're my preferred
>> IR photodiode supplier--their stuff is good, it
>> costs 1/3 to 1/2 of what Hamamatsu wants for the
>> same thing, and you can get the designer on the
>> phone. Cheers Phil Hobbs
>
> This one?
>
> Gpd Optoelectronics Corp
> 7 Manor Parkway
> Salem, NH 03079-2842
>
> (603) 894-6865
>
Yup. Ask for George.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Greegor●August 30, 20132013-08-30
> GPD is a pretty good outfit. They're my preferred
> IR photodiode supplier--their stuff is good, it
> costs 1/3 to 1/2 of what Hamamatsu wants for the
> same thing, and you can get the designer on the
> phone. Cheers Phil Hobbs
> On 8/29/2013 3:04 PM, John Larkin wrote:
>> On Thu, 29 Aug 2013 14:12:18 -0400, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> On 08/29/2013 11:40 AM, John Larkin wrote:
>>>> On Thu, 29 Aug 2013 07:43:18 -0700, Joerg <invalid@invalid.invalid>
>>>> wrote:
>>>>
>>>>> John Larkin wrote:
>>>>>> On Wed, 28 Aug 2013 22:55:24 +0000, chris <meru@devnull.com> wrote:
>>>>>>
>>>>>>> On 08/28/13 17:53, Jim Thompson wrote:
>>>>>>>
>>>>>>>> In the mid to late '80's I used 1N270's by the bucket load to clamp
>>>>>>>> LM324 and LM329 inputs, to avoid substrate diode injection and
>>>>>>>> phase
>>>>>>>> inversion.
>>>>>>>>
>>>>>>>> ...Jim Thompson
>>>>>>> Anyone remember the GE "back" diodes ?. Same can as their tunnel
>>>>>>> diodes,
>>>>>>> but, iirc, very low forward voltage...
>>>>>>>
>>>>>>> Chris
>>>>>>
>>>>>> People still make Ge back diodes, as rf detectors. They are, I think,
>>>>>> the only planar "ic" type fabrication done in germanium, except
>>>>>> photodiodes maybe.
>>>>>>
>>>>>
>>>>> In Europe we had mesa and planar Ge RF transistors. For example, this
>>>>> one was a hot commodity among the "discarded TV set pilfering" crowd
>>>>> because you could often find them hidden as the only transistors in
>>>>> tube
>>>>> sets:
>>>>>
>>>>> http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html
>>>>>
>>>>>
>>>>> [...]
>>>>
>>>> There were big TO3 and stud Ge power transistors, and I'm guessing
>>>> that they
>>>> were a planar structure. If anybody has one, maybe they could decap
>>>> it and take
>>>> pictures.
>>>>
>>>> Germanium Power Devices was, I think, the last maker of Ge diodes and
>>>> transistors. They are now "GPD" and make photodiodes.
>>>>
>>>> I think someone still makes Ge tunnel diodes.
>>>>
>>>>
>>> GPD is a pretty good outfit. They're my preferred IR photodiode
>>> supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
>>> wants for the same thing, and you can get the designer on the phone.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> Is "Oliver Germanium" still in charge?
>
> I think his son runs it now, but he's still around. IIRC Fred Molinari
> still runs Data Translation, too. ;)
Looks like I was out of date--I asked my GPD friends about Oliver a few
years ago, and he was still extant.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Phil Hobbs●August 29, 20132013-08-29
On 8/29/2013 3:04 PM, John Larkin wrote:
> On Thu, 29 Aug 2013 14:12:18 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> On 08/29/2013 11:40 AM, John Larkin wrote:
>>> On Thu, 29 Aug 2013 07:43:18 -0700, Joerg <invalid@invalid.invalid> wrote:
>>>
>>>> John Larkin wrote:
>>>>> On Wed, 28 Aug 2013 22:55:24 +0000, chris <meru@devnull.com> wrote:
>>>>>
>>>>>> On 08/28/13 17:53, Jim Thompson wrote:
>>>>>>
>>>>>>> In the mid to late '80's I used 1N270's by the bucket load to clamp
>>>>>>> LM324 and LM329 inputs, to avoid substrate diode injection and phase
>>>>>>> inversion.
>>>>>>>
>>>>>>> ...Jim Thompson
>>>>>> Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
>>>>>> but, iirc, very low forward voltage...
>>>>>>
>>>>>> Chris
>>>>>
>>>>> People still make Ge back diodes, as rf detectors. They are, I think,
>>>>> the only planar "ic" type fabrication done in germanium, except
>>>>> photodiodes maybe.
>>>>>
>>>>
>>>> In Europe we had mesa and planar Ge RF transistors. For example, this
>>>> one was a hot commodity among the "discarded TV set pilfering" crowd
>>>> because you could often find them hidden as the only transistors in tube
>>>> sets:
>>>>
>>>> http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html
>>>>
>>>> [...]
>>>
>>> There were big TO3 and stud Ge power transistors, and I'm guessing that they
>>> were a planar structure. If anybody has one, maybe they could decap it and take
>>> pictures.
>>>
>>> Germanium Power Devices was, I think, the last maker of Ge diodes and
>>> transistors. They are now "GPD" and make photodiodes.
>>>
>>> I think someone still makes Ge tunnel diodes.
>>>
>>>
>> GPD is a pretty good outfit. They're my preferred IR photodiode
>> supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
>> wants for the same thing, and you can get the designer on the phone.
>>
>> Cheers
>>
>> Phil Hobbs
>
> Is "Oliver Germanium" still in charge?
I think his son runs it now, but he's still around. IIRC Fred Molinari
still runs Data Translation, too. ;)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058
hobbs at electrooptical dot net
http://electrooptical.net
Reply by John Larkin●August 29, 20132013-08-29
On Thu, 29 Aug 2013 14:15:39 -0500, "Tim Williams"
<tmoranwms@charter.net> wrote:
>"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
>message news:etpu19p50d4l8jaicuacck1ulu0t9lh4hf@4ax.com...
>> WWII radars used silicon, germanium, and even gaas point-contact diodes.
>> One of
>> the RadLab books casually mentions that "a semiconductor triode should
>> be
>> possible."
>
>Indeed. I recall reading an article about researchers trying that (a
>triode) since about the turn of the century. Copper oxide doesn't even
>make good rectifiers, let alone transistors, but the idea was there.
>
>I forget when the FET was invented, but it predated the BJT theoretically
>by some time; only after substantial process refinements were they finally
>able to minimize surface states and make the things.
The boys at Bell Labs were actually trying to make a jfet, which their
materials weren't up to. As I recall reading somewhere, the bjt was an
accidental outcome of that attempt.
I had lunch with Walter Brattain once when I was a kid, but I didn't
know enough to ask him any good questions.
>
>It's also cool that vacuum tubes work on the same theoretical principles:
>charge transfer between dissimilar media, Fermi potentials, thermal
>energy, band gaps; all the same, except semiconductors work on bulk
>diffusion and charges spanning the band gap, while vacuum tubes work on
>ballistic transport and electrons above the vacuum potential (no holes).
>
>> One whole volume of the RadLab books is "Crystal Rectifiers." They knew
>> a lot
>> about semiconductor physics in 1940.
>>
>> https://dl.dropboxusercontent.com/u/53724080/Parts/RadLabDiodes.JPG
>
>Notice that, unlike a semiconductor diode [in the absence of light], the
>6AL5 is an overunity diode (notice the zero intercept). :)
>
>Yeah, making an "in the absence of light" comparison is silly because the
>6AL5 makes a little light, too. (I've seen at least one eBay auction
>advertising the worthless buggers for Christmas tree lights and other
>assorted uses...) The actual thermodynamics are, of course, a very
>inefficient heat pump.
I started with tubes, and I don't miss them a bit.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation
Reply by Spehro Pefhany●August 29, 20132013-08-29
On Thu, 29 Aug 2013 14:12:18 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>On 08/29/2013 11:40 AM, John Larkin wrote:
>> On Thu, 29 Aug 2013 07:43:18 -0700, Joerg <invalid@invalid.invalid> wrote:
>>
>>> John Larkin wrote:
>>>> On Wed, 28 Aug 2013 22:55:24 +0000, chris <meru@devnull.com> wrote:
>>>>
>>>>> On 08/28/13 17:53, Jim Thompson wrote:
>>>>>
>>>>>> In the mid to late '80's I used 1N270's by the bucket load to clamp
>>>>>> LM324 and LM329 inputs, to avoid substrate diode injection and phase
>>>>>> inversion.
>>>>>>
>>>>>> ...Jim Thompson
>>>>> Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
>>>>> but, iirc, very low forward voltage...
>>>>>
>>>>> Chris
>>>>
>>>> People still make Ge back diodes, as rf detectors. They are, I think,
>>>> the only planar "ic" type fabrication done in germanium, except
>>>> photodiodes maybe.
>>>>
>>>
>>> In Europe we had mesa and planar Ge RF transistors. For example, this
>>> one was a hot commodity among the "discarded TV set pilfering" crowd
>>> because you could often find them hidden as the only transistors in tube
>>> sets:
>>>
>>> http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html
>>>
>>> [...]
>>
>> There were big TO3 and stud Ge power transistors, and I'm guessing that they
>> were a planar structure. If anybody has one, maybe they could decap it and take
>> pictures.
>>
>> Germanium Power Devices was, I think, the last maker of Ge diodes and
>> transistors. They are now "GPD" and make photodiodes.
>>
>> I think someone still makes Ge tunnel diodes.
>>
>>
>GPD is a pretty good outfit. They're my preferred IR photodiode
>supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
>wants for the same thing, and you can get the designer on the phone.
>
>Cheers
>
>Phil Hobbs
"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message news:etpu19p50d4l8jaicuacck1ulu0t9lh4hf@4ax.com...
> WWII radars used silicon, germanium, and even gaas point-contact diodes.
> One of
> the RadLab books casually mentions that "a semiconductor triode should
> be
> possible."
Indeed. I recall reading an article about researchers trying that (a
triode) since about the turn of the century. Copper oxide doesn't even
make good rectifiers, let alone transistors, but the idea was there.
I forget when the FET was invented, but it predated the BJT theoretically
by some time; only after substantial process refinements were they finally
able to minimize surface states and make the things.
It's also cool that vacuum tubes work on the same theoretical principles:
charge transfer between dissimilar media, Fermi potentials, thermal
energy, band gaps; all the same, except semiconductors work on bulk
diffusion and charges spanning the band gap, while vacuum tubes work on
ballistic transport and electrons above the vacuum potential (no holes).
Notice that, unlike a semiconductor diode [in the absence of light], the
6AL5 is an overunity diode (notice the zero intercept). :)
Yeah, making an "in the absence of light" comparison is silly because the
6AL5 makes a little light, too. (I've seen at least one eBay auction
advertising the worthless buggers for Christmas tree lights and other
assorted uses...) The actual thermodynamics are, of course, a very
inefficient heat pump.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com
Reply by John Larkin●August 29, 20132013-08-29
On Thu, 29 Aug 2013 14:12:18 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>On 08/29/2013 11:40 AM, John Larkin wrote:
>> On Thu, 29 Aug 2013 07:43:18 -0700, Joerg <invalid@invalid.invalid> wrote:
>>
>>> John Larkin wrote:
>>>> On Wed, 28 Aug 2013 22:55:24 +0000, chris <meru@devnull.com> wrote:
>>>>
>>>>> On 08/28/13 17:53, Jim Thompson wrote:
>>>>>
>>>>>> In the mid to late '80's I used 1N270's by the bucket load to clamp
>>>>>> LM324 and LM329 inputs, to avoid substrate diode injection and phase
>>>>>> inversion.
>>>>>>
>>>>>> ...Jim Thompson
>>>>> Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
>>>>> but, iirc, very low forward voltage...
>>>>>
>>>>> Chris
>>>>
>>>> People still make Ge back diodes, as rf detectors. They are, I think,
>>>> the only planar "ic" type fabrication done in germanium, except
>>>> photodiodes maybe.
>>>>
>>>
>>> In Europe we had mesa and planar Ge RF transistors. For example, this
>>> one was a hot commodity among the "discarded TV set pilfering" crowd
>>> because you could often find them hidden as the only transistors in tube
>>> sets:
>>>
>>> http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html
>>>
>>> [...]
>>
>> There were big TO3 and stud Ge power transistors, and I'm guessing that they
>> were a planar structure. If anybody has one, maybe they could decap it and take
>> pictures.
>>
>> Germanium Power Devices was, I think, the last maker of Ge diodes and
>> transistors. They are now "GPD" and make photodiodes.
>>
>> I think someone still makes Ge tunnel diodes.
>>
>>
>GPD is a pretty good outfit. They're my preferred IR photodiode
>supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
>wants for the same thing, and you can get the designer on the phone.
>
>Cheers
>
>Phil Hobbs
Is "Oliver Germanium" still in charge?
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation
Reply by Phil Hobbs●August 29, 20132013-08-29
On 08/29/2013 11:40 AM, John Larkin wrote:
> On Thu, 29 Aug 2013 07:43:18 -0700, Joerg <invalid@invalid.invalid> wrote:
>
>> John Larkin wrote:
>>> On Wed, 28 Aug 2013 22:55:24 +0000, chris <meru@devnull.com> wrote:
>>>
>>>> On 08/28/13 17:53, Jim Thompson wrote:
>>>>
>>>>> In the mid to late '80's I used 1N270's by the bucket load to clamp
>>>>> LM324 and LM329 inputs, to avoid substrate diode injection and phase
>>>>> inversion.
>>>>>
>>>>> ...Jim Thompson
>>>> Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
>>>> but, iirc, very low forward voltage...
>>>>
>>>> Chris
>>>
>>> People still make Ge back diodes, as rf detectors. They are, I think,
>>> the only planar "ic" type fabrication done in germanium, except
>>> photodiodes maybe.
>>>
>>
>> In Europe we had mesa and planar Ge RF transistors. For example, this
>> one was a hot commodity among the "discarded TV set pilfering" crowd
>> because you could often find them hidden as the only transistors in tube
>> sets:
>>
>> http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html
>>
>> [...]
>
> There were big TO3 and stud Ge power transistors, and I'm guessing that they
> were a planar structure. If anybody has one, maybe they could decap it and take
> pictures.
>
> Germanium Power Devices was, I think, the last maker of Ge diodes and
> transistors. They are now "GPD" and make photodiodes.
>
> I think someone still makes Ge tunnel diodes.
>
>
GPD is a pretty good outfit. They're my preferred IR photodiode
supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
wants for the same thing, and you can get the designer on the phone.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net