On Sun, 23 Feb 2020 22:07:55 -0800 (PST), Michael Terrell <terrell.michael.a@gmail.com> wrote:>On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, highlandsniptechnology wrote: >> On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote: >> >> >On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote: >> >> On 2020-02-23 15:56, jlarkin wrote: >> >> > >> >> > https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/ >> >> > >> >> > >> >> > >> >> Gee, I wish I were smart enough to design that. >> >> >> >> I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to >> >> make it work at higher bandwidth, by using gussied-up Darlington >> >> connections with 40-GHz SiGe:C NPNs to return the AC base current to the >> >> collector circuit. >> >> >> >> It didn't work, because AFFLICT there's no simple way to get rid of the >> >> time constants formed by Rbb' and the interelectrode capacitances >> >> without trashing the noise. >> > >> > >> > That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV. >> >> The guy is no lightweght. Maybe he was in a hurry or something. > >Which guy? There are too many guys in this thread. :)Dr. Sergio Franco. -- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
2 GHz buffer with 2N390x
Started by ●February 23, 2020
Reply by ●February 24, 20202020-02-24
Reply by ●February 24, 20202020-02-24
Michael Terrell <terrell.michael.a@gmail.com> wrote in news:50569bec-b527-4165-a912-bc7f25c2c375@googlegroups.com:> On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, > highlandsniptechnology wrote: >> On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote: >> >> >On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs >> >wrote: >> >> On 2020-02-23 15:56, jlarkin wrote: >> >> > >> >> > https://www.allaboutcircuits.com/technical-articles/voltage-b >> >> > uffer-s > imulation-composite-amplifier-simulation-boost-output-current-drive > / >> >> > >> >> > >> >> > >> >> Gee, I wish I were smart enough to design that. >> >> >> >> I once tried fairly hard to bandage up a MAT14 supermatch quad >> >> NPN to > >> >> make it work at higher bandwidth, by using gussied-up >> >> Darlington connections with 40-GHz SiGe:C NPNs to return the >> >> AC base current to t > he >> >> collector circuit. >> >> >> >> It didn't work, because AFFLICT there's no simple way to get >> >> rid of th > e >> >> time constants formed by Rbb' and the interelectrode >> >> capacitances without trashing the noise. >> > >> > >> > That reminds of of a guy with a brand new two year degree who >> > believe > that he could get 5W of RF at 27 MHz form a 2N3055. I gave him > one. As I expected, he didn't even get a miliwatt output, which > was as low as I could measure in my home shop at 17. He was like > Sloman. He knew everything, yet he often needed help to repair a > TV. >> >> The guy is no lightweght. Maybe he was in a hurry or something. > > Which guy? There are too many guys in this thread. :)You would like to come in here under that guise, but we have the evidence! You are all tied up in the guy wires.
Reply by ●February 24, 20202020-02-24
On Monday, February 24, 2020 at 5:05:29 PM UTC+11, Michael Terrell wrote:> On Sunday, February 23, 2020 at 10:39:15 PM UTC-5, Tim Williams wrote: > > "Michael Terrell" wrote in message > > news:1085d865-ec53-4158-aa2b-1446fff74951@googlegroups.com... > > > That reminds of of a guy with a brand new two year degree who believe > > > that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I > > > expected, he didn't even get a miliwatt output, which was as low as I > > > could measure in my home shop at 17. He was like Sloman. He knew > > > everything, yet he often needed help to repair a TV. > > > > > > > Entirely possible that he had done this, using a brand new epitaxial '3055. > > Which shouldn't even exist, it should've been discontinued and put in a new > > type number, say. While the one you had was made on the old process, and > > barely useful for audio. > > > > Although getting 5W even from an epitaxial version would probably require > > more skill than he had, anyway. I'm not doubting that possibility. > > > > Tim > > > It was in a Pace 2300, a popular CB radio made by Pathcom in the '60s and '70s. He was convinced that the custom RF output in a TO-3 was just an ordinary audio transistor. I showed him the RCA Databook that showed it had no chance of working. He claimed that RCA didn't know what they were doing. The Databook was from 1967, and I may still have it somewhere. > > He had an attitude like Sloman. Anyone with a degree was infallible, and anyone else didn't deserve to live.Michael Terrell doesn't seem to noticed that I don't have any kind of degree in electronics - my Ph.D. is physical chemistry. I don't think that anybody would ever think that anybody with a degree would be infallible, and I've certainly worked with enough people with degrees to be well aware that it isn't remotely true.> I used to piss him off when I passed his bench at the shop. I would tell him what part was bad. He would curse me out, but more often than not he would yell, Do we have that part in stock? I took care of repairs of industrial electronics, and I knew our inventory better than anyone in the shop.A useful skill. -- Bill Sloman, Sydney
Reply by ●February 24, 20202020-02-24
On Monday, February 24, 2020 at 1:23:38 AM UTC-5, jla...@highlandsniptechnology.com wrote:> On Sun, 23 Feb 2020 22:07:55 -0800 (PST), Michael Terrell > <terrell.michael.a@gmail.com> wrote: > > >On Sunday, February 23, 2020 at 8:26:09 PM UTC-5, highlandsniptechnology wrote: > >> On Sun, 23 Feb 2020 16:34:51 -0800 (PST), Michael Terrell wrote: > >> > >> >On Sunday, February 23, 2020 at 4:42:53 PM UTC-5, Phil Hobbs wrote: > >> >> On 2020-02-23 15:56, jlarkin wrote: > >> >> > > >> >> > https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/ > >> >> > > >> >> > > >> >> > > >> >> Gee, I wish I were smart enough to design that. > >> >> > >> >> I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to > >> >> make it work at higher bandwidth, by using gussied-up Darlington > >> >> connections with 40-GHz SiGe:C NPNs to return the AC base current to the > >> >> collector circuit. > >> >> > >> >> It didn't work, because AFFLICT there's no simple way to get rid of the > >> >> time constants formed by Rbb' and the interelectrode capacitances > >> >> without trashing the noise. > >> > > >> > > >> > That reminds of of a guy with a brand new two year degree who believe that he could get 5W of RF at 27 MHz form a 2N3055. I gave him one. As I expected, he didn't even get a miliwatt output, which was as low as I could measure in my home shop at 17. He was like Sloman. He knew everything, yet he often needed help to repair a TV. > >> > >> The guy is no lightweght. Maybe he was in a hurry or something. > > > >Which guy? There are too many guys in this thread. :) > > Dr. Sergio Franco.Huh S. Franco wrote one of my favorite opamp books. I better go read the article. (I thought it was hooey from the comments.) George H.> > > > > -- > > John Larkin Highland Technology, Inc > > The cork popped merrily, and Lord Peter rose to his feet. > "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Reply by ●February 24, 20202020-02-24
On Sunday, February 23, 2020 at 5:02:33 PM UTC-5, jla...@highlandsniptechnology.com wrote:> On Sun, 23 Feb 2020 16:42:42 -0500, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > > >On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote: > >> > >> https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/ > >> > >> > >> > >Gee, I wish I were smart enough to design that. > > > >I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to > >make it work at higher bandwidth, by using gussied-up Darlington > >connections with 40-GHz SiGe:C NPNs to return the AC base current to the > >collector circuit. > > > >It didn't work, because AFAICT there's no simple way to get rid of the > >time constants formed by Rbb' and the interelectrode capacitances > >without trashing the noise. > > > >Cheers > > > >Phil Hobbs > > Looking at his graphs, I figure that after the Ft's run out, the > signal is coupled through the various Cbe's. But that's not much in > the way of gain. Thermal runaway could be interesting too.Huh OK his gain graph droops at ~100MHz... So what is the Ft (typical) of a 2n3904? George H.> > The electronic mags are pitiful these days. > > Speaking of buffers, BUF602 is slick. > > > > -- > > John Larkin Highland Technology, Inc > > The cork popped merrily, and Lord Peter rose to his feet. > "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Reply by ●February 24, 20202020-02-24
On Mon, 24 Feb 2020 09:15:38 -0800 (PST), George Herold <ggherold@gmail.com> wrote:>On Sunday, February 23, 2020 at 5:02:33 PM UTC-5, jla...@highlandsniptechnology.com wrote: >> On Sun, 23 Feb 2020 16:42:42 -0500, Phil Hobbs >> <pcdhSpamMeSenseless@electrooptical.net> wrote: >> >> >On 2020-02-23 15:56, jlarkin@highlandsniptechnology.com wrote: >> >> >> >> https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/ >> >> >> >> >> >> >> >Gee, I wish I were smart enough to design that. >> > >> >I once tried fairly hard to bandage up a MAT14 supermatch quad NPN to >> >make it work at higher bandwidth, by using gussied-up Darlington >> >connections with 40-GHz SiGe:C NPNs to return the AC base current to the >> >collector circuit. >> > >> >It didn't work, because AFAICT there's no simple way to get rid of the >> >time constants formed by Rbb' and the interelectrode capacitances >> >without trashing the noise. >> > >> >Cheers >> > >> >Phil Hobbs >> >> Looking at his graphs, I figure that after the Ft's run out, the >> signal is coupled through the various Cbe's. But that's not much in >> the way of gain. Thermal runaway could be interesting too. > >Huh OK his gain graph droops at ~100MHz... >So what is the Ft (typical) of a 2n3904?250 MHz sort of range. The PNP is a bit less than the NPN. -- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Reply by ●February 24, 20202020-02-24
George Herold <ggherold@gmail.com> writes:> Huh OK his gain graph droops at ~100MHz... > So what is the Ft (typical) of a 2n3904?I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and generic partnumbers, too. -- mikko
Reply by ●February 24, 20202020-02-24
On Monday, February 24, 2020 at 4:36:47 PM UTC-5, Mikko OH2HVJ wrote:> George Herold <ggherold@gmail.com> writes: > > > Huh OK his gain graph droops at ~100MHz... > > So what is the Ft (typical) of a 2n3904? > > I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and > generic partnumbers, too. > > -- > mikkoThanks! GH
Reply by ●February 24, 20202020-02-24
On 2020-02-24 16:36, Mikko OH2HVJ wrote:> George Herold <ggherold@gmail.com> writes: > >> Huh OK his gain graph droops at ~100MHz... >> So what is the Ft (typical) of a 2n3904? > > I've measured 30-300 MHz depending on mfg 1994-2015. Processes evolve and > generic partnumbers, too. >30 MHz peak f_T for a 2N3904? 350-400 MHz at ~10-30 mA iirc. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●February 24, 20202020-02-24
On 2020-02-23 12:56, jlarkin@highlandsniptechnology.com wrote:> > https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifier-simulation-boost-output-current-drive/ >That reminds me of the moped tuning that the guys did in my high school days. Going 50mph on a screaming 50ccm engine running way beyond redline. Unfortunately one classmate died that way, the brakes couldn't hold up. -- Regards, Joerg http://www.analogconsultants.com/
