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
1N34A Germanium Diode finally found!!
Started by ●August 27, 2013
Reply by ●August 29, 20132013-08-29
Reply by ●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 HobbsIs "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 ●August 29, 20132013-08-29
"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).> 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.JPGNotice 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 ●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 HobbsR.I.P. "Oliver Germanium". http://www.legacy.com/obituaries/bostonglobe/obituary.aspx?n=oliver-o-ward&pid=153956149#fbLoggedOut
Reply by ●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 ●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 ●August 29, 20132013-08-29
On 8/29/2013 5:19 PM, Phil Hobbs wrote:> 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 ●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 HobbsThis one? Gpd Optoelectronics Corp 7 Manor Parkway Salem, NH 03079-2842 (603) 894-6865
Reply by ●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 ●September 13, 20132013-09-13
