High Quality White Noise Gen
in [Design]
|
From: Bill Sloman on 6 Jun 2010 18:37 On Jun 6, 10:36 pm, George Herold <gher...(a)teachspin.com> wrote: > On Jun 5, 6:52 pm, John Larkin > > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > > On Sat, 5 Jun 2010 15:00:09 -0700 (PDT),Bill Sloman > > > <bill.slo...(a)ieee.org> wrote: > > >On Jun 5, 8:18 pm, John Larkin > > ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > > >> On Sat, 5 Jun 2010 10:47:26 -0700 (PDT),Bill Sloman > > > >> <bill.slo...(a)ieee.org> wrote: > > >> >On Jun 5, 1:24 am, John Larkin > > >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > > >> >> On Fri, 4 Jun 2010 14:56:44 -0700 (PDT),Bill Sloman > > > >> >> <bill.slo...(a)ieee.org> wrote: > > >> >> >On Jun 4, 10:40 pm, Phil Hobbs > > >> >> ><pcdhSpamMeSensel...(a)electrooptical.net> wrote: > > >> >> >> On 6/4/2010 12:01 PM,Bill Slomanwrote: > > > >> >> >> > On Jun 4, 4:41 pm, George Herold<gher...(a)teachspin.com> wrote: > > >> >> >> >> On Jun 4, 10:07 am, Phil Hobbs > > > >> >> >> >> <pcdhSpamMeSensel...(a)electrooptical.net> wrote: > > >> >> >> >>> On 6/3/2010 11:12 PM, George Herold wrote: > > > >> >> >> >>>> langw...(a)fonz.dk wrote: > > >> >> >> >>>>> On 3 Jun., 23:11, Phil Hobbs<pcdhSpamMeSensel...(a)electrooptical.net> > > >> >> >> >>>>> wrote: > > >> >> >> >>>>>> On 6/3/2010 9:49 AM, George Herold wrote: > > > >> >> >> >>>>>>> On Jun 2, 4:36 pm, John Larkin > > >> >> >> >>>>>>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > > >> >> >> >>>>>>>> On Wed, 2 Jun 2010 12:30:19 -0700 (PDT), George Herold > > > >> >> >> >>>>>>>> <gher...(a)teachspin.com> wrote: > > >> >> >> >>>>>>>>> On Jun 2, 1:59 pm, whit3rd<whit...(a)gmail.com> wrote: > > >> >> >> >>>>>>>>>> On Jun 2, 10:37 am, George Herold<gher...(a)teachspin..com> wrote: > > > ><snip> > > > >> >> >> > You might want to search on single photon avalanche photo-detection. > > > >> >> >> >http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-3-2232 > > > >> >> >> > I haven't looked at the full paper but the list of references includes > > >> >> >> > some useful stuff. > > > >> >> >> Geiger-mode APDs are mostly a crock unless you need timing accuracy > > >> >> >> better than, say, 10 ns. Their dark count rate is a good six orders of > > >> >> >> magnitude worse than a PMT of the same area, and their dead time is 10 > > >> >> >> times longer. > > > >> >> >> On the other hand, they don't die if you put them in a helium > > >> >> >> atmosphere, and they last longer than 5 years. And they can offer single photon detection of longer wavelength photons than any photomultiplier tube can pick up. For some apllication this is vital. > > >> >> >Horses for courses. They can be a lot more compact and robust than > > >> >> >PMTs - on which I'm rather more expert. > > > >> >> Vain fathead. > > > >> >I've worked with PMT's - which is more than I can claim about SPAD's - > > >> >and I've persuaded the IEEE that I do know a little about PMTs - see > > >> >the IEEE Transactions on Electronic Devices volume 38 pages 679-680, > > >> >published in March 1991. > > > >> >You do need to base your abuse on something more than your right-wing > > >> >intuition. Going off half-cocked like this does rather expose your > > >> >enthusiasm for believeing what you want to believe despite the absence > > >> >of any evidence to support your point of view. > > > >> All you do here is claim how "expert" you are, or maybe were, without > > >> ever making actual contributions. > > > >Nothing that you'd be willing to acknowledge, particularly since most > > >of my contributions are references to the publshed literature, a > > >source that you seem ill-equipped to exploit > > > >> You never *do* anything. > > > >Not at the moment, and I find it frustrating. > > > >> And when I don't have convincing evidence, I experiment and collect > > >> some. A mouse isn't a soldering iron. > > > >You burble about 140dB of ripple rejection > > > Burble? > > Maybe he say you coming through the turgey(sp) wood. Charles Lutwidge Dodgson worked as an academic mathematician in the areas of geometry, matrix algebra and mathematical logic, none of which would appeal to John Larkin. > > I questioned whether the Spice models of the c-multiplier were > > accurate at mid-frequencies. None came close to 140, or even 80, dB at > > frequencies where Early slope matters. So I tried some experiments. > > The Early effect goes away at at high frequencies? No, but it tends to get swamped by Miller capacitance. -- Bill Sloman, Nijmegen
From: John Larkin on 6 Jun 2010 21:35 On Sun, 6 Jun 2010 13:36:09 -0700 (PDT), George Herold <gherold(a)teachspin.com> wrote: >On Jun 5, 6:52�pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Sat, 5 Jun 2010 15:00:09 -0700 (PDT), Bill Sloman >> >> >> >> >> >> <bill.slo...(a)ieee.org> wrote: >> >On Jun 5, 8:18�pm, John Larkin >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> On Sat, 5 Jun 2010 10:47:26 -0700 (PDT),Bill Sloman >> >> >> <bill.slo...(a)ieee.org> wrote: >> >> >On Jun 5, 1:24�am, John Larkin >> >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >> On Fri, 4 Jun 2010 14:56:44 -0700 (PDT),Bill Sloman >> >> >> >> <bill.slo...(a)ieee.org> wrote: >> >> >> >On Jun 4, 10:40�pm, Phil Hobbs >> >> >> ><pcdhSpamMeSensel...(a)electrooptical.net> wrote: >> >> >> >> On 6/4/2010 12:01 PM,Bill Slomanwrote: >> >> >> >> >> > On Jun 4, 4:41 pm, George Herold<gher...(a)teachspin.com> �wrote: >> >> >> >> >> On Jun 4, 10:07 am, Phil Hobbs >> >> >> >> >> >> <pcdhSpamMeSensel...(a)electrooptical.net> �wrote: >> >> >> >> >>> On 6/3/2010 11:12 PM, George Herold wrote: >> >> >> >> >> >>>> langw...(a)fonz.dk wrote: >> >> >> >> >>>>> On 3 Jun., 23:11, Phil Hobbs<pcdhSpamMeSensel...(a)electrooptical.net> >> >> >> >> >>>>> wrote: >> >> >> >> >>>>>> On 6/3/2010 9:49 AM, George Herold wrote: >> >> >> >> >> >>>>>>> On Jun 2, 4:36 pm, John Larkin >> >> >> >> >>>>>>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> � � �wrote: >> >> >> >> >>>>>>>> On Wed, 2 Jun 2010 12:30:19 -0700 (PDT), George Herold >> >> >> >> >> >>>>>>>> <gher...(a)teachspin.com> � � �wrote: >> >> >> >> >>>>>>>>> On Jun 2, 1:59 pm, whit3rd<whit...(a)gmail.com> � � �wrote: >> >> >> >> >>>>>>>>>> On Jun 2, 10:37 am, George Herold<gher...(a)teachspin.com> � � �wrote: >> >> ><snip> >> >> >> >> >> > You might want to search on single photon avalanche photo-detection. >> >> >> >> >> >http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-3-2232 >> >> >> >> >> > I haven't looked at the full paper but the list of references includes >> >> >> >> > some useful stuff. >> >> >> >> >> Geiger-mode APDs are mostly a crock unless you need timing accuracy >> >> >> >> better than, say, 10 ns. �Their dark count rate is a good six orders of >> >> >> >> magnitude worse than a PMT of the same area, and their dead time is 10 >> >> >> >> times longer. >> >> >> >> >> On the other hand, they don't die if you put them in a helium >> >> >> >> atmosphere, and they last longer than 5 years. >> >> >> >> >Horses for courses. They can be a lot more compact and robust than >> >> >> >PMTs - on which I'm rather more expert. >> >> >> >> Vain fathead. >> >> >> >I've worked with PMT's - which is more than I can claim about SPAD's - >> >> >and I've persuaded the IEEE that I do know a little about PMTs - see >> >> >the IEEE Transactions on Electronic Devices volume 38 pages 679-680, >> >> >published in March 1991. >> >> >> >You do need to base your abuse on something more than your right-wing >> >> >intuition. Going off half-cocked like this does rather expose your >> >> >enthusiasm for believeing what you want to believe despite the absence >> >> >of any evidence to support your point of view. >> >> >> All you do here is claim how "expert" you are, or maybe were, without >> >> ever making actual contributions. >> >> >Nothing that you'd be willing to acknowledge, particularly since most >> >of my contributions are references to the publshed literature, a >> >source that you seem ill-equipped to exploit >> >> >> You never *do* anything. >> >> >Not at the moment, and I find it frustrating. >> >> >> And when I don't have convincing evidence, I experiment and collect >> >> some. A mouse isn't a soldering iron. >> >> >You burble about 140dB of ripple rejection >> >> Burble? >Maybe he say you coming through the turgey(sp) wood. > >> I questioned whether the Spice models of the c-multiplier were >> accurate at mid-frequencies. None came close to 140, or even 80, dB at >> frequencies where Early slope matters. So I tried some experiments. > >The Early effect goes away at at high frequencies? No, but the optput capacitor impedance continues to decline. There are a few frequency zones: Dc to where the base lowpass filter kicks in: 0 dB ripple attenuation. A region where the Early thing works, roughly -50 dB. A slope downward, beginning at the corner frequency set by Re and the output filter capacitance Cf. Some high frequency where the attenuation is Cf/Cce More or less. I was interested in that second one, where simple calculations or Spice aren't necessarily predictive. John
From: John Larkin on 6 Jun 2010 21:36 On Sun, 6 Jun 2010 13:54:05 -0700 (PDT), George Herold <gherold(a)teachspin.com> wrote: >On Jun 6, 4:46�pm, "k...(a)att.bizzzzzzzzzzzz" <k...(a)att.bizzzzzzzzzzzz> >wrote: >> On Sun, 6 Jun 2010 13:36:09 -0700 (PDT), George Herold <gher...(a)teachspin.com> >> wrote: >> >> >> >> >> >> >On Jun 5, 6:52 pm, John Larkin >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> On Sat, 5 Jun 2010 15:00:09 -0700 (PDT), Bill Sloman >> >> >> <bill.slo...(a)ieee.org> wrote: >> >> >On Jun 5, 8:18 pm, John Larkin >> >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >> On Sat, 5 Jun 2010 10:47:26 -0700 (PDT),Bill Sloman >> >> >> >> <bill.slo...(a)ieee.org> wrote: >> >> >> >On Jun 5, 1:24 am, John Larkin >> >> >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >> >> On Fri, 4 Jun 2010 14:56:44 -0700 (PDT),Bill Sloman >> >> >> >> >> <bill.slo...(a)ieee.org> wrote: >> >> >> >> >On Jun 4, 10:40 pm, Phil Hobbs >> >> >> >> ><pcdhSpamMeSensel...(a)electrooptical.net> wrote: >> >> >> >> >> On 6/4/2010 12:01 PM,Bill Slomanwrote: >> >> >> >> >> >> > On Jun 4, 4:41 pm, George Herold<gher...(a)teachspin.com> wrote: >> >> >> >> >> >> On Jun 4, 10:07 am, Phil Hobbs >> >> >> >> >> >> >> <pcdhSpamMeSensel...(a)electrooptical.net> wrote: >> >> >> >> >> >>> On 6/3/2010 11:12 PM, George Herold wrote: >> >> >> >> >> >> >>>> langw...(a)fonz.dk wrote: >> >> >> >> >> >>>>> On 3 Jun., 23:11, Phil Hobbs<pcdhSpamMeSensel...(a)electrooptical.net> >> >> >> >> >> >>>>> wrote: >> >> >> >> >> >>>>>> On 6/3/2010 9:49 AM, George Herold wrote: >> >> >> >> >> >> >>>>>>> On Jun 2, 4:36 pm, John Larkin >> >> >> >> >> >>>>>>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >> >> >> >>>>>>>> On Wed, 2 Jun 2010 12:30:19 -0700 (PDT), George Herold >> >> >> >> >> >> >>>>>>>> <gher...(a)teachspin.com> wrote: >> >> >> >> >> >>>>>>>>> On Jun 2, 1:59 pm, whit3rd<whit...(a)gmail.com> wrote: >> >> >> >> >> >>>>>>>>>> On Jun 2, 10:37 am, George Herold<gher...(a)teachspin.com> wrote: >> >> >> ><snip> >> >> >> >> >> >> > You might want to search on single photon avalanche photo-detection. >> >> >> >> >> >> >http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-3-2232 >> >> >> >> >> >> > I haven't looked at the full paper but the list of references includes >> >> >> >> >> > some useful stuff. >> >> >> >> >> >> Geiger-mode APDs are mostly a crock unless you need timing accuracy >> >> >> >> >> better than, say, 10 ns. Their dark count rate is a good six orders of >> >> >> >> >> magnitude worse than a PMT of the same area, and their dead time is 10 >> >> >> >> >> times longer. >> >> >> >> >> >> On the other hand, they don't die if you put them in a helium >> >> >> >> >> atmosphere, and they last longer than 5 years. >> >> >> >> >> >Horses for courses. They can be a lot more compact and robust than >> >> >> >> >PMTs - on which I'm rather more expert. >> >> >> >> >> Vain fathead. >> >> >> >> >I've worked with PMT's - which is more than I can claim about SPAD's - >> >> >> >and I've persuaded the IEEE that I do know a little about PMTs - see >> >> >> >the IEEE Transactions on Electronic Devices volume 38 pages 679-680, >> >> >> >published in March 1991. >> >> >> >> >You do need to base your abuse on something more than your right-wing >> >> >> >intuition. Going off half-cocked like this does rather expose your >> >> >> >enthusiasm for believeing what you want to believe despite the absence >> >> >> >of any evidence to support your point of view. >> >> >> >> All you do here is claim how "expert" you are, or maybe were, without >> >> >> ever making actual contributions. >> >> >> >Nothing that you'd be willing to acknowledge, particularly since most >> >> >of my contributions are references to the publshed literature, a >> >> >source that you seem ill-equipped to exploit >> >> >> >> You never *do* anything. >> >> >> >Not at the moment, and I find it frustrating. >> >> >> >> And when I don't have convincing evidence, I experiment and collect >> >> >> some. A mouse isn't a soldering iron. >> >> >> >You burble about 140dB of ripple rejection >> >> >> Burble? >> >Maybe he say you coming through the turgey(sp) wood. >> >> >> I questioned whether the Spice models of the c-multiplier were >> >> accurate at mid-frequencies. None came close to 140, or even 80, dB at >> >> frequencies where Early slope matters. So I tried some experiments. >> >> >The Early effect goes away at at high frequencies? >> >> At high frequencies other parasitics become more important? �Early gets >> swamped by Cce?- Hide quoted text - >> >> - Show quoted text - > >Hmm OK... LTspice didn't seem to show that, (90dB of attenuation at >100kHz), but maybe I have to do some real measurements. I'm afraid I >don't really understand the Early effect/ voltage. > Just imagine a resistor from collector to emitter. The question is, what's the value? John
From: John Larkin on 6 Jun 2010 21:41 On Sun, 6 Jun 2010 15:37:19 -0700 (PDT), Bill Sloman <bill.sloman(a)ieee.org> wrote: >On Jun 6, 10:36�pm, George Herold <gher...(a)teachspin.com> wrote: >> On Jun 5, 6:52�pm, John Larkin >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> > On Sat, 5 Jun 2010 15:00:09 -0700 (PDT),Bill Sloman >> >> > <bill.slo...(a)ieee.org> wrote: >> > >On Jun 5, 8:18�pm, John Larkin >> > ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> > >> On Sat, 5 Jun 2010 10:47:26 -0700 (PDT),Bill Sloman >> >> > >> <bill.slo...(a)ieee.org> wrote: >> > >> >On Jun 5, 1:24�am, John Larkin >> > >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> > >> >> On Fri, 4 Jun 2010 14:56:44 -0700 (PDT),Bill Sloman >> >> > >> >> <bill.slo...(a)ieee.org> wrote: >> > >> >> >On Jun 4, 10:40�pm, Phil Hobbs >> > >> >> ><pcdhSpamMeSensel...(a)electrooptical.net> wrote: >> > >> >> >> On 6/4/2010 12:01 PM,Bill Slomanwrote: >> >> > >> >> >> > On Jun 4, 4:41 pm, George Herold<gher...(a)teachspin.com> �wrote: >> > >> >> >> >> On Jun 4, 10:07 am, Phil Hobbs >> >> > >> >> >> >> <pcdhSpamMeSensel...(a)electrooptical.net> �wrote: >> > >> >> >> >>> On 6/3/2010 11:12 PM, George Herold wrote: >> >> > >> >> >> >>>> langw...(a)fonz.dk wrote: >> > >> >> >> >>>>> On 3 Jun., 23:11, Phil Hobbs<pcdhSpamMeSensel...(a)electrooptical.net> >> > >> >> >> >>>>> wrote: >> > >> >> >> >>>>>> On 6/3/2010 9:49 AM, George Herold wrote: >> >> > >> >> >> >>>>>>> On Jun 2, 4:36 pm, John Larkin >> > >> >> >> >>>>>>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> � � �wrote: >> > >> >> >> >>>>>>>> On Wed, 2 Jun 2010 12:30:19 -0700 (PDT), George Herold >> >> > >> >> >> >>>>>>>> <gher...(a)teachspin.com> � � �wrote: >> > >> >> >> >>>>>>>>> On Jun 2, 1:59 pm, whit3rd<whit...(a)gmail.com> � � �wrote: >> > >> >> >> >>>>>>>>>> On Jun 2, 10:37 am, George Herold<gher...(a)teachspin.com> � � �wrote: >> >> > ><snip> >> >> > >> >> >> > You might want to search on single photon avalanche photo-detection. >> >> > >> >> >> >http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-3-2232 >> >> > >> >> >> > I haven't looked at the full paper but the list of references includes >> > >> >> >> > some useful stuff. >> >> > >> >> >> Geiger-mode APDs are mostly a crock unless you need timing accuracy >> > >> >> >> better than, say, 10 ns. �Their dark count rate is a good six orders of >> > >> >> >> magnitude worse than a PMT of the same area, and their dead time is 10 >> > >> >> >> times longer. >> >> > >> >> >> On the other hand, they don't die if you put them in a helium >> > >> >> >> atmosphere, and they last longer than 5 years. > >And they can offer single photon detection of longer wavelength >photons than any photomultiplier tube can pick up. For some >apllication this is vital. > >> > >> >> >Horses for courses. They can be a lot more compact and robust than >> > >> >> >PMTs - on which I'm rather more expert. >> >> > >> >> Vain fathead. >> >> > >> >I've worked with PMT's - which is more than I can claim about SPAD's - >> > >> >and I've persuaded the IEEE that I do know a little about PMTs - see >> > >> >the IEEE Transactions on Electronic Devices volume 38 pages 679-680, >> > >> >published in March 1991. >> >> > >> >You do need to base your abuse on something more than your right-wing >> > >> >intuition. Going off half-cocked like this does rather expose your >> > >> >enthusiasm for believeing what you want to believe despite the absence >> > >> >of any evidence to support your point of view. >> >> > >> All you do here is claim how "expert" you are, or maybe were, without >> > >> ever making actual contributions. >> >> > >Nothing that you'd be willing to acknowledge, particularly since most >> > >of my contributions are references to the publshed literature, a >> > >source that you seem ill-equipped to exploit >> >> > >> You never *do* anything. >> >> > >Not at the moment, and I find it frustrating. >> >> > >> And when I don't have convincing evidence, I experiment and collect >> > >> some. A mouse isn't a soldering iron. >> >> > >You burble about 140dB of ripple rejection >> >> > Burble? >> >> Maybe he say you coming through the turgey(sp) wood. Tulgey. > >Charles Lutwidge Dodgson worked as an academic mathematician in the >areas of geometry, matrix algebra and mathematical logic, none of >which would appeal to John Larkin. I can recite "Jabberwocky" by heart, and do sometimes if the beer or wine are of sufficient quality. This Bandit chardonnay here is actually pretty good. John
From: Bill Sloman on 6 Jun 2010 22:19
On Jun 7, 3:41 am, John Larkin <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > On Sun, 6 Jun 2010 15:37:19 -0700 (PDT),Bill Sloman > > > > <bill.slo...(a)ieee.org> wrote: > >On Jun 6, 10:36 pm, George Herold <gher...(a)teachspin.com> wrote: > >> On Jun 5, 6:52 pm, John Larkin > > >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> > On Sat, 5 Jun 2010 15:00:09 -0700 (PDT),Bill Sloman > > >> > <bill.slo...(a)ieee.org> wrote: > >> > >On Jun 5, 8:18 pm, John Larkin > >> > ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> > >> On Sat, 5 Jun 2010 10:47:26 -0700 (PDT),Bill Sloman > > >> > >> <bill.slo...(a)ieee.org> wrote: > >> > >> >On Jun 5, 1:24 am, John Larkin > >> > >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> > >> >> On Fri, 4 Jun 2010 14:56:44 -0700 (PDT),Bill Sloman > > >> > >> >> <bill.slo...(a)ieee.org> wrote: > >> > >> >> >On Jun 4, 10:40 pm, Phil Hobbs > >> > >> >> ><pcdhSpamMeSensel...(a)electrooptical.net> wrote: > >> > >> >> >> On 6/4/2010 12:01 PM,Bill Slomanwrote: > > >> > >> >> >> > On Jun 4, 4:41 pm, George Herold<gher...(a)teachspin.com> wrote: > >> > >> >> >> >> On Jun 4, 10:07 am, Phil Hobbs > > >> > >> >> >> >> <pcdhSpamMeSensel...(a)electrooptical.net> wrote: > >> > >> >> >> >>> On 6/3/2010 11:12 PM, George Herold wrote: > > >> > >> >> >> >>>> langw...(a)fonz.dk wrote: > >> > >> >> >> >>>>> On 3 Jun., 23:11, Phil Hobbs<pcdhSpamMeSensel...(a)electrooptical.net> > >> > >> >> >> >>>>> wrote: > >> > >> >> >> >>>>>> On 6/3/2010 9:49 AM, George Herold wrote: > > >> > >> >> >> >>>>>>> On Jun 2, 4:36 pm, John Larkin > >> > >> >> >> >>>>>>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> > >> >> >> >>>>>>>> On Wed, 2 Jun 2010 12:30:19 -0700 (PDT), George Herold > > >> > >> >> >> >>>>>>>> <gher...(a)teachspin.com> wrote: > >> > >> >> >> >>>>>>>>> On Jun 2, 1:59 pm, whit3rd<whit...(a)gmail.com> wrote: > >> > >> >> >> >>>>>>>>>> On Jun 2, 10:37 am, George Herold<gher...(a)teachspin.com> wrote: > > >> > ><snip> > > >> > >> >> >> > You might want to search on single photon avalanche photo-detection. > > >> > >> >> >> >http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-3-2232 > > >> > >> >> >> > I haven't looked at the full paper but the list of references includes > >> > >> >> >> > some useful stuff. > > >> > >> >> >> Geiger-mode APDs are mostly a crock unless you need timing accuracy > >> > >> >> >> better than, say, 10 ns. Their dark count rate is a good six orders of > >> > >> >> >> magnitude worse than a PMT of the same area, and their dead time is 10 > >> > >> >> >> times longer. > > >> > >> >> >> On the other hand, they don't die if you put them in a helium > >> > >> >> >> atmosphere, and they last longer than 5 years. > > >And they can offer single photon detection of longer wavelength > >photons than any photomultiplier tube can pick up. For some > >apllication this is vital. > > >> > >> >> >Horses for courses. They can be a lot more compact and robust than > >> > >> >> >PMTs - on which I'm rather more expert. > > >> > >> >> Vain fathead. > > >> > >> >I've worked with PMT's - which is more than I can claim about SPAD's - > >> > >> >and I've persuaded the IEEE that I do know a little about PMTs - see > >> > >> >the IEEE Transactions on Electronic Devices volume 38 pages 679-680, > >> > >> >published in March 1991. > > >> > >> >You do need to base your abuse on something more than your right-wing > >> > >> >intuition. Going off half-cocked like this does rather expose your > >> > >> >enthusiasm for believeing what you want to believe despite the absence > >> > >> >of any evidence to support your point of view. > > >> > >> All you do here is claim how "expert" you are, or maybe were, without > >> > >> ever making actual contributions. > > >> > >Nothing that you'd be willing to acknowledge, particularly since most > >> > >of my contributions are references to the publshed literature, a > >> > >source that you seem ill-equipped to exploit > > >> > >> You never *do* anything. > > >> > >Not at the moment, and I find it frustrating. > > >> > >> And when I don't have convincing evidence, I experiment and collect > >> > >> some. A mouse isn't a soldering iron. > > >> > >You burble about 140dB of ripple rejection > > >> > Burble? > > >> Maybe he say you coming through the turgey(sp) wood. > > Tulgey. > > > > >Charles Lutwidge Dodgson worked as an academic mathematician in the > >areas of geometry, matrix algebra and mathematical logic, none of > >which would appeal to John Larkin. > > I can recite "Jabberwocky" by heart, and do sometimes if the beer or > wine are of sufficient quality. > > This Bandit chardonnay here is actually pretty good. My wife recently found an excuse to open some of our 2004 Gosset Polish Hill Riesling - last year she thought that the 2003 was better, but this year the 2004 does seem to come into its own. http://www.grosset.com.au/wines_polishhillriesling.htm Happily, it doesn't inspire either of us to recite poetry. If it did, this might be more appropriate than "Jabberwocky". http://www.poetry-online.org/chesterton_wine_and_water.htm -- Bill Sloman, Nijmegen |