"Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message news:ld5psq$s5m$1@dont-email.me...> On 8.2.14 19:01, Ian Field wrote: >> >> >> "miso" <miso@sushi.com> wrote in message >> news:ld3msp$d62$1@speranza.aioe.org... >>> Ian Field wrote: >>> >>>> >>>> >>>> <haiticare2011@gmail.com> wrote in message >>>> news:6473bf77-f37e-4207-81a1-7bba9945a7ba@googlegroups.com... >>>>> I remember reading some while ago that LLL was working with fast >>>>> switching transistors which generated "radar wavelength" signals. >>>>> Then, >>>>> as events go, a Georgia Tech Prof. raised a stink since he had >>>>> previously >>>>> developed those applications. Again, a vague memory. Does anyone >>>>> recall >>>>> this? >>>> >>>> On one of my downloading sprees, I got various radar circuit schematics >>>> with a smattering of transistor types and vintage stuff dating back to >>>> WW2. >>>> >>>> A prominent book on the site I think they might have come from is: >>>> gunplexer cookbook, if you search that you might find a site with all >>>> kinds of UHF/EHF military stuff. >>>> >>>> If you're doing really low power stuff, the ZTX415 avalanche transistor >>>> might do for producing narrow pulses - you go for a Vcc of 60V or more, >>>> your energy storage device is a tuned length of co-ax cable, you set >>>> the >>>> transistor up just short of breakdown and trigger it with a pulse to >>>> the >>>> base. Pulsewidths of a few nS are a typical application. >>> >>> How do you focus the energy? A dish is broadband, but the feed horn >>> generally is a band limited device. >> >> No idea - I only read little bits I can find about radar out of idle >> curiosity. >> >> Its my understanding so far, that waveguides can be tuned pretty sharp. > > You're probably thinking about cavity resonators. Waveguides are > transmission lines, and they are not supposed to resonate.I may not know much about radar, but I have seen technical articles about tuning waveguides. Various devices like stubs and/or vanes and adjustable plates are used to tune a waveguide. Apparently a vane at one aspect of the aperture constitutes capacitive tuning and on the other aspect its inductive tuning. The simplest view of a cavity, is a stub of waveguide with one end blanked off.
Radar generating transistor circuit?
Started by ●February 7, 2014
Reply by ●February 8, 20142014-02-08
Reply by ●February 8, 20142014-02-08
On 8.2.14 19:43, Ian Field wrote:> > > "Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message > news:ld5psq$s5m$1@dont-email.me... >> On 8.2.14 19:01, Ian Field wrote: >>> >>> >>> "miso" <miso@sushi.com> wrote in message >>> news:ld3msp$d62$1@speranza.aioe.org... >>>> Ian Field wrote: >>>> >>>>> >>>>> >>>>> <haiticare2011@gmail.com> wrote in message >>>>> news:6473bf77-f37e-4207-81a1-7bba9945a7ba@googlegroups.com... >>>>>> I remember reading some while ago that LLL was working with fast >>>>>> switching transistors which generated "radar wavelength" signals. >>>>>> Then, >>>>>> as events go, a Georgia Tech Prof. raised a stink since he had >>>>>> previously >>>>>> developed those applications. Again, a vague memory. Does anyone >>>>>> recall >>>>>> this? >>>>> >>>>> On one of my downloading sprees, I got various radar circuit >>>>> schematics >>>>> with a smattering of transistor types and vintage stuff dating back to >>>>> WW2. >>>>> >>>>> A prominent book on the site I think they might have come from is: >>>>> gunplexer cookbook, if you search that you might find a site with all >>>>> kinds of UHF/EHF military stuff. >>>>> >>>>> If you're doing really low power stuff, the ZTX415 avalanche >>>>> transistor >>>>> might do for producing narrow pulses - you go for a Vcc of 60V or >>>>> more, >>>>> your energy storage device is a tuned length of co-ax cable, you >>>>> set the >>>>> transistor up just short of breakdown and trigger it with a pulse >>>>> to the >>>>> base. Pulsewidths of a few nS are a typical application. >>>> >>>> How do you focus the energy? A dish is broadband, but the feed horn >>>> generally is a band limited device. >>> >>> No idea - I only read little bits I can find about radar out of idle >>> curiosity. >>> >>> Its my understanding so far, that waveguides can be tuned pretty sharp. >> >> You're probably thinking about cavity resonators. Waveguides are >> transmission lines, and they are not supposed to resonate. > > I may not know much about radar, but I have seen technical articles > about tuning waveguides. > > Various devices like stubs and/or vanes and adjustable plates are used > to tune a waveguide. Apparently a vane at one aspect of the aperture > constitutes capacitive tuning and on the other aspect its inductive tuning. > > The simplest view of a cavity, is a stub of waveguide with one end > blanked off.As soon as you disrupt a waveguide, it quits being a plain waveguide, and begins to be some kind of cavity. About a quarter century ago, I had problems with a waveguide (1.5 by 3 inches) which started arcing over at 800 kW instead of gtransporting the supposed 1500 kW neatly. The problem was located to a transport dent near the antenna feed point. -- -TV
Reply by ●February 8, 20142014-02-08
"Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message news:ld643o$rrg$1@dont-email.me...> On 8.2.14 19:43, Ian Field wrote: >> >> >> "Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message >> news:ld5psq$s5m$1@dont-email.me... >>> On 8.2.14 19:01, Ian Field wrote: >>>> >>>> >>>> "miso" <miso@sushi.com> wrote in message >>>> news:ld3msp$d62$1@speranza.aioe.org... >>>>> Ian Field wrote: >>>>> >>>>>> >>>>>> >>>>>> <haiticare2011@gmail.com> wrote in message >>>>>> news:6473bf77-f37e-4207-81a1-7bba9945a7ba@googlegroups.com... >>>>>>> I remember reading some while ago that LLL was working with fast >>>>>>> switching transistors which generated "radar wavelength" signals. >>>>>>> Then, >>>>>>> as events go, a Georgia Tech Prof. raised a stink since he had >>>>>>> previously >>>>>>> developed those applications. Again, a vague memory. Does anyone >>>>>>> recall >>>>>>> this? >>>>>> >>>>>> On one of my downloading sprees, I got various radar circuit >>>>>> schematics >>>>>> with a smattering of transistor types and vintage stuff dating back >>>>>> to >>>>>> WW2. >>>>>> >>>>>> A prominent book on the site I think they might have come from is: >>>>>> gunplexer cookbook, if you search that you might find a site with all >>>>>> kinds of UHF/EHF military stuff. >>>>>> >>>>>> If you're doing really low power stuff, the ZTX415 avalanche >>>>>> transistor >>>>>> might do for producing narrow pulses - you go for a Vcc of 60V or >>>>>> more, >>>>>> your energy storage device is a tuned length of co-ax cable, you >>>>>> set the >>>>>> transistor up just short of breakdown and trigger it with a pulse >>>>>> to the >>>>>> base. Pulsewidths of a few nS are a typical application. >>>>> >>>>> How do you focus the energy? A dish is broadband, but the feed horn >>>>> generally is a band limited device. >>>> >>>> No idea - I only read little bits I can find about radar out of idle >>>> curiosity. >>>> >>>> Its my understanding so far, that waveguides can be tuned pretty sharp. >>> >>> You're probably thinking about cavity resonators. Waveguides are >>> transmission lines, and they are not supposed to resonate. >> >> I may not know much about radar, but I have seen technical articles >> about tuning waveguides. >> >> Various devices like stubs and/or vanes and adjustable plates are used >> to tune a waveguide. Apparently a vane at one aspect of the aperture >> constitutes capacitive tuning and on the other aspect its inductive >> tuning. >> >> The simplest view of a cavity, is a stub of waveguide with one end >> blanked off. > > As soon as you disrupt a waveguide, it quits being a plain waveguide, > and begins to be some kind of cavity. > > About a quarter century ago, I had problems with a waveguide > (1.5 by 3 inches) which started arcing over at 800 kW instead > of gtransporting the supposed 1500 kW neatly. The problem was > located to a transport dent near the antenna feed point.I pretty much suggested as much without resorting to telling my life story.
Reply by ●February 8, 20142014-02-08
On 08/02/14 02:28, John Larkin wrote:> On Fri, 7 Feb 2014 05:09:02 -0800 (PST), haiticare2011@gmail.com wrote: >> I remember reading some while ago that LLL was working with fast switching transistors which generated "radar wavelength" signals. Then, as events go, a Georgia Tech Prof. raised a stink since he had previously developed those applications. Again, a vague memory. Does anyone recall this? > The idea was broadband impulse radar, using step-recovery diode pulsers and some > sort of audio-IF-range receive mixer. The guy was McKeon or something like that. > He has a bunch of patents, and started his own company, but it didn't seem to > go.They had a patent battle with a Canadian company called Time Domain Systems, and lost. You can find 20 or so of Tom McEwan's patents pretty easily, and some even have full schematics with everyday components.
Reply by ●February 8, 20142014-02-08
On Sat, 8 Feb 2014 21:40:53 -0000, "Ian Field" <gangprobing.alien@ntlworld.com> wrote:> > >"Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message >news:ld643o$rrg$1@dont-email.me... >> On 8.2.14 19:43, Ian Field wrote: >>> >>> >>> "Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message >>> news:ld5psq$s5m$1@dont-email.me... >>>> On 8.2.14 19:01, Ian Field wrote: >>>>> >>>>> >>>>> "miso" <miso@sushi.com> wrote in message >>>>> news:ld3msp$d62$1@speranza.aioe.org... >>>>>> Ian Field wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> <haiticare2011@gmail.com> wrote in message >>>>>>> news:6473bf77-f37e-4207-81a1-7bba9945a7ba@googlegroups.com... >>>>>>>> I remember reading some while ago that LLL was working with fast >>>>>>>> switching transistors which generated "radar wavelength" signals. >>>>>>>> Then, >>>>>>>> as events go, a Georgia Tech Prof. raised a stink since he had >>>>>>>> previously >>>>>>>> developed those applications. Again, a vague memory. Does anyone >>>>>>>> recall >>>>>>>> this? >>>>>>> >>>>>>> On one of my downloading sprees, I got various radar circuit >>>>>>> schematics >>>>>>> with a smattering of transistor types and vintage stuff dating back >>>>>>> to >>>>>>> WW2. >>>>>>> >>>>>>> A prominent book on the site I think they might have come from is: >>>>>>> gunplexer cookbook, if you search that you might find a site with all >>>>>>> kinds of UHF/EHF military stuff. >>>>>>> >>>>>>> If you're doing really low power stuff, the ZTX415 avalanche >>>>>>> transistor >>>>>>> might do for producing narrow pulses - you go for a Vcc of 60V or >>>>>>> more, >>>>>>> your energy storage device is a tuned length of co-ax cable, you >>>>>>> set the >>>>>>> transistor up just short of breakdown and trigger it with a pulse >>>>>>> to the >>>>>>> base. Pulsewidths of a few nS are a typical application. >>>>>> >>>>>> How do you focus the energy? A dish is broadband, but the feed horn >>>>>> generally is a band limited device. >>>>> >>>>> No idea - I only read little bits I can find about radar out of idle >>>>> curiosity. >>>>> >>>>> Its my understanding so far, that waveguides can be tuned pretty sharp. >>>> >>>> You're probably thinking about cavity resonators. Waveguides are >>>> transmission lines, and they are not supposed to resonate. >>> >>> I may not know much about radar, but I have seen technical articles >>> about tuning waveguides. >>> >>> Various devices like stubs and/or vanes and adjustable plates are used >>> to tune a waveguide. Apparently a vane at one aspect of the aperture >>> constitutes capacitive tuning and on the other aspect its inductive >>> tuning. >>> >>> The simplest view of a cavity, is a stub of waveguide with one end >>> blanked off. >> >> As soon as you disrupt a waveguide, it quits being a plain waveguide, >> and begins to be some kind of cavity. >> >> About a quarter century ago, I had problems with a waveguide >> (1.5 by 3 inches) which started arcing over at 800 kW instead >> of gtransporting the supposed 1500 kW neatly. The problem was >> located to a transport dent near the antenna feed point. > >I pretty much suggested as much without resorting to telling my life story.--- A wise move since low Q tends to damp a resonance instead of exalting it.
Reply by ●February 8, 20142014-02-08
"John Fields" <jfields@austininstruments.com> wrote in message news:juadf9p38kfvm23hg8qvpreulol46u0r44@4ax.com...> On Sat, 8 Feb 2014 21:40:53 -0000, "Ian Field" > <gangprobing.alien@ntlworld.com> wrote: > >> >> >>"Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message >>news:ld643o$rrg$1@dont-email.me... >>> On 8.2.14 19:43, Ian Field wrote: >>>> >>>> >>>> "Tauno Voipio" <tauno.voipio@notused.fi.invalid> wrote in message >>>> news:ld5psq$s5m$1@dont-email.me... >>>>> On 8.2.14 19:01, Ian Field wrote: >>>>>> >>>>>> >>>>>> "miso" <miso@sushi.com> wrote in message >>>>>> news:ld3msp$d62$1@speranza.aioe.org... >>>>>>> Ian Field wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> <haiticare2011@gmail.com> wrote in message >>>>>>>> news:6473bf77-f37e-4207-81a1-7bba9945a7ba@googlegroups.com... >>>>>>>>> I remember reading some while ago that LLL was working with fast >>>>>>>>> switching transistors which generated "radar wavelength" signals. >>>>>>>>> Then, >>>>>>>>> as events go, a Georgia Tech Prof. raised a stink since he had >>>>>>>>> previously >>>>>>>>> developed those applications. Again, a vague memory. Does anyone >>>>>>>>> recall >>>>>>>>> this? >>>>>>>> >>>>>>>> On one of my downloading sprees, I got various radar circuit >>>>>>>> schematics >>>>>>>> with a smattering of transistor types and vintage stuff dating back >>>>>>>> to >>>>>>>> WW2. >>>>>>>> >>>>>>>> A prominent book on the site I think they might have come from is: >>>>>>>> gunplexer cookbook, if you search that you might find a site with >>>>>>>> all >>>>>>>> kinds of UHF/EHF military stuff. >>>>>>>> >>>>>>>> If you're doing really low power stuff, the ZTX415 avalanche >>>>>>>> transistor >>>>>>>> might do for producing narrow pulses - you go for a Vcc of 60V or >>>>>>>> more, >>>>>>>> your energy storage device is a tuned length of co-ax cable, you >>>>>>>> set the >>>>>>>> transistor up just short of breakdown and trigger it with a pulse >>>>>>>> to the >>>>>>>> base. Pulsewidths of a few nS are a typical application. >>>>>>> >>>>>>> How do you focus the energy? A dish is broadband, but the feed horn >>>>>>> generally is a band limited device. >>>>>> >>>>>> No idea - I only read little bits I can find about radar out of idle >>>>>> curiosity. >>>>>> >>>>>> Its my understanding so far, that waveguides can be tuned pretty >>>>>> sharp. >>>>> >>>>> You're probably thinking about cavity resonators. Waveguides are >>>>> transmission lines, and they are not supposed to resonate. >>>> >>>> I may not know much about radar, but I have seen technical articles >>>> about tuning waveguides. >>>> >>>> Various devices like stubs and/or vanes and adjustable plates are used >>>> to tune a waveguide. Apparently a vane at one aspect of the aperture >>>> constitutes capacitive tuning and on the other aspect its inductive >>>> tuning. >>>> >>>> The simplest view of a cavity, is a stub of waveguide with one end >>>> blanked off. >>> >>> As soon as you disrupt a waveguide, it quits being a plain waveguide, >>> and begins to be some kind of cavity. >>> >>> About a quarter century ago, I had problems with a waveguide >>> (1.5 by 3 inches) which started arcing over at 800 kW instead >>> of gtransporting the supposed 1500 kW neatly. The problem was >>> located to a transport dent near the antenna feed point. >> >>I pretty much suggested as much without resorting to telling my life >>story. > > --- > A wise move since low Q tends to damp a resonance instead of > exalting it.You haven't stalked me for a while - I thought you'd died.
Reply by ●February 8, 20142014-02-08
Robert Baer wrote:> > John Larkin wrote: > > > > http://www.osti.gov/includes/doepatents/includes/MicroPower.pdf > > > Address Not Found > > www.osti.gov could not be found. Please check the name and try again.Worked for me. Right click and saved, then opened fine. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
Reply by ●February 8, 20142014-02-08
On Sat, 8 Feb 2014 22:20:44 -0000, "Ian Field" <gangprobing.alien@ntlworld.com> wrote:> > >"John Fields" <jfields@austininstruments.com> wrote in message >news:juadf9p38kfvm23hg8qvpreulol46u0r44@4ax.com... >> On Sat, 8 Feb 2014 21:40:53 -0000, "Ian Field" >> <gangprobing.alien@ntlworld.com> wrote:. . .>>>I pretty much suggested as much without resorting to telling my life >>>story. >> >> --- >> A wise move since low Q tends to damp a resonance instead of >> exalting it. > >You haven't stalked me for a while--- Watching a cockroach scamper across the floor is hardly stalking... --->I thought you'd died.--- That pretty much seems to go hand-in-hand with the rest of your "thinking".
Reply by ●February 9, 20142014-02-09
On 9/02/2014 10:46 AM, John Fields wrote:> On Sat, 8 Feb 2014 22:20:44 -0000, "Ian Field" > <gangprobing.alien@ntlworld.com> wrote: >> "John Fields" <jfields@austininstruments.com> wrote in message >> news:juadf9p38kfvm23hg8qvpreulol46u0r44@4ax.com... >>> On Sat, 8 Feb 2014 21:40:53 -0000, "Ian Field" >>> <gangprobing.alien@ntlworld.com> wrote:><snip>>>>> I pretty much suggested as much without resorting to telling my life >>>> story. >>> >>> A wise move since low Q tends to damp a resonance instead of >>> exalting it. >> >> You haven't stalked me for a while > > Watching a cockroach scamper across the floor is hardly stalking...Except that in this context, John Fields is the cockroach.>> I thought you'd died. > > That pretty much seems to go hand-in-hand with the rest of your > "thinking".Wishful thinking is popular. I don't think Ian Fields is any more guilty of it than the rest of us. You - for instance - expect to be taken seriously. I'm not that optimistic. -- Bill Sloman, Sydney
Reply by ●February 9, 20142014-02-09
On Sun, 09 Feb 2014 15:30:49 +1100, Bill Sloman <cutlersloman@tpg.com.au> wrote:>On 9/02/2014 10:46 AM, John Fields wrote: >> On Sat, 8 Feb 2014 22:20:44 -0000, "Ian Field" >> <gangprobing.alien@ntlworld.com> wrote: >>> "John Fields" <jfields@austininstruments.com> wrote in message >>> news:juadf9p38kfvm23hg8qvpreulol46u0r44@4ax.com... >>>> On Sat, 8 Feb 2014 21:40:53 -0000, "Ian Field" >>>> <gangprobing.alien@ntlworld.com> wrote: > > ><snip> > >>>>> I pretty much suggested as much without resorting to telling my life >>>>> story. >>>> >>>> A wise move since low Q tends to damp a resonance instead of >>>> exalting it. >>> >>> You haven't stalked me for a while >> >> Watching a cockroach scamper across the floor is hardly stalking... > >Except that in this context, John Fields is the cockroach.--- One would expect you'd feel that way, your parsing skills being what they are. --->>> I thought you'd died. >> >> That pretty much seems to go hand-in-hand with the rest of your >> "thinking". > >Wishful thinking is popular. I don't think Ian Fields is any more guilty >of it than the rest of us. You - for instance - expect to be taken >seriously. I'm not that optimistic.--- With good reason.
