On 2/1/2022 12:59 PM, jlarkin@highlandsniptechnology.com wrote:> On Tue, 1 Feb 2022 12:05:49 -0500, bitrex <user@example.net> wrote: > >> On 2/1/2022 11:07 AM, jlarkin@highlandsniptechnology.com wrote: >>> On Tue, 1 Feb 2022 10:59:09 -0500, Phil Hobbs >>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>> >>>> piglet wrote: >>>>> On 01/02/2022 3:27 pm, jlarkin@highlandsniptechnology.com wrote: >>>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>>> >>>>>> >>>>> >>>>> Yes, decades ago I built something similar using an NPN BJT at kHz >>>>> frequencies. I used two molded chokes and had initially them loose >>>>> coupled but was amazed that I could separate them or re-orient so there >>>>> was no mutual couplling and still got oscillation. >>>>> >>>>> I think Irving Gottlieb described three types of Hartley in his >>>>> Oscillator Handbook and this is one of his "type 2" Hartleys, there is >>>>> no mutual coupling and the action is negative resistance. >>>>> >>>>> piglet >>>>> >>>>> >>>>> With no coupling, it's a species of Colpitts--it's only the tank Q that >>>> does the impedance transformation, with no help from the transformer >>>> action of the mutual inductance. >>>> >>>> Cheers >>>> >>>> Phil Hobbs >>> >>> I was just fooling around. What I really want is a 1.5 GHz oscillator >>> with two antiphase outputs. A MMIC might be a good gain element. >> >> What about cross-coupled ECL-type oscillator > > I could persuade a diff-in-out ecl gate or comparator to oscillate, > but I'd have to try it. I don't have Spice models for those. > > I might get lucky and just connect a diff gate into itself, inverted. > and watch it oscillate. Hey good idea! Might be fun to try. > > A MMIC is a great gain element, but it's basically 50 ohms in and out, > the ideal tank Q killer. The best MMIC ocillator is probably > delay-line, which will give me antiphase outputs. Again, gotta solder > to test that.If I recall there's a way to get a lil chain of D-type flip-flops to self-oscillate, functioning as a self-oscillating ring counter/delay line, but I'm not sure there's any e.g. TinyLogic-type parts that can be coaxed to 1+ GHz, as the minimum propagation time I think tends to be 2-3 ns> I wish ADI would include their ADCMP parts in LT Spice.
strange oscillator
Started by ●February 1, 2022
Reply by ●February 2, 20222022-02-02
Reply by ●February 2, 20222022-02-02
onsdag den 2. februar 2022 kl. 16.45.55 UTC+1 skrev bitrex:> On 2/1/2022 12:59 PM, jla...@highlandsniptechnology.com wrote: > > On Tue, 1 Feb 2022 12:05:49 -0500, bitrex <us...@example.net> wrote: > > > >> On 2/1/2022 11:07 AM, jla...@highlandsniptechnology.com wrote: > >>> On Tue, 1 Feb 2022 10:59:09 -0500, Phil Hobbs > >>> <pcdhSpamM...@electrooptical.net> wrote: > >>> > >>>> piglet wrote: > >>>>> On 01/02/2022 3:27 pm, jla...@highlandsniptechnology.com wrote: > >>>>>> Not actually a Hartley, bacause the Ls are not coupled. > >>>>> > >>>>>> > >>>>> > >>>>> Yes, decades ago I built something similar using an NPN BJT at kHz > >>>>> frequencies. I used two molded chokes and had initially them loose > >>>>> coupled but was amazed that I could separate them or re-orient so there > >>>>> was no mutual couplling and still got oscillation. > >>>>> > >>>>> I think Irving Gottlieb described three types of Hartley in his > >>>>> Oscillator Handbook and this is one of his "type 2" Hartleys, there is > >>>>> no mutual coupling and the action is negative resistance. > >>>>> > >>>>> piglet > >>>>> > >>>>> > >>>>> With no coupling, it's a species of Colpitts--it's only the tank Q that > >>>> does the impedance transformation, with no help from the transformer > >>>> action of the mutual inductance. > >>>> > >>>> Cheers > >>>> > >>>> Phil Hobbs > >>> > >>> I was just fooling around. What I really want is a 1.5 GHz oscillator > >>> with two antiphase outputs. A MMIC might be a good gain element. > >> > >> What about cross-coupled ECL-type oscillator > > > > I could persuade a diff-in-out ecl gate or comparator to oscillate, > > but I'd have to try it. I don't have Spice models for those. > > > > I might get lucky and just connect a diff gate into itself, inverted. > > and watch it oscillate. Hey good idea! Might be fun to try. > > > > A MMIC is a great gain element, but it's basically 50 ohms in and out, > > the ideal tank Q killer. The best MMIC ocillator is probably > > delay-line, which will give me antiphase outputs. Again, gotta solder > > to test that. > If I recall there's a way to get a lil chain of D-type flip-flops to > self-oscillate, functioning as a self-oscillating ring counter/delay > line, but I'm not sure there's any e.g. TinyLogic-type parts that can be > coaxed to 1+ GHz, as the minimum propagation time I think tends to be 2-3 nshttps://hackaday.io/project/28833-microhacks/log/157535-just-how-fast-are-74auc-gates
Reply by ●February 2, 20222022-02-02
On Wed, 2 Feb 2022 10:45:42 -0500, bitrex <user@example.net> wrote:>On 2/1/2022 12:59 PM, jlarkin@highlandsniptechnology.com wrote: >> On Tue, 1 Feb 2022 12:05:49 -0500, bitrex <user@example.net> wrote: >> >>> On 2/1/2022 11:07 AM, jlarkin@highlandsniptechnology.com wrote: >>>> On Tue, 1 Feb 2022 10:59:09 -0500, Phil Hobbs >>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>> >>>>> piglet wrote: >>>>>> On 01/02/2022 3:27 pm, jlarkin@highlandsniptechnology.com wrote: >>>>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>>>> >>>>>>> >>>>>> >>>>>> Yes, decades ago I built something similar using an NPN BJT at kHz >>>>>> frequencies. I used two molded chokes and had initially them loose >>>>>> coupled but was amazed that I could separate them or re-orient so there >>>>>> was no mutual couplling and still got oscillation. >>>>>> >>>>>> I think Irving Gottlieb described three types of Hartley in his >>>>>> Oscillator Handbook and this is one of his "type 2" Hartleys, there is >>>>>> no mutual coupling and the action is negative resistance. >>>>>> >>>>>> piglet >>>>>> >>>>>> >>>>>> With no coupling, it's a species of Colpitts--it's only the tank Q that >>>>> does the impedance transformation, with no help from the transformer >>>>> action of the mutual inductance. >>>>> >>>>> Cheers >>>>> >>>>> Phil Hobbs >>>> >>>> I was just fooling around. What I really want is a 1.5 GHz oscillator >>>> with two antiphase outputs. A MMIC might be a good gain element. >>> >>> What about cross-coupled ECL-type oscillator >> >> I could persuade a diff-in-out ecl gate or comparator to oscillate, >> but I'd have to try it. I don't have Spice models for those. >> >> I might get lucky and just connect a diff gate into itself, inverted. >> and watch it oscillate. Hey good idea! Might be fun to try. >> >> A MMIC is a great gain element, but it's basically 50 ohms in and out, >> the ideal tank Q killer. The best MMIC ocillator is probably >> delay-line, which will give me antiphase outputs. Again, gotta solder >> to test that. > >If I recall there's a way to get a lil chain of D-type flip-flops to >self-oscillate, functioning as a self-oscillating ring counter/delay >line, but I'm not sure there's any e.g. TinyLogic-type parts that can be >coaxed to 1+ GHz, as the minimum propagation time I think tends to be 2-3 nsWe use Eclips Lite gates, 3 GHz stuff, and the fast ADCMP series comparators. Even a few GigaComm parts, roughly 7 GHz. There is some really fast logic around, ballpark 10 ps, but it's like hundreds of dollars per gate. -- I yam what I yam - Popeye
Reply by ●February 3, 20222022-02-03
jlarkin@highlandsniptechnology.com wrote:> On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spamme@not.com> > wrote: > >>jlarkin@highlandsniptechnology.com wrote: >> >>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer <spamme@not.com> >>> wrote: >>> >>>>jlarkin@highlandsniptechnology.com wrote: >>>> >>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>> >>>>[...] >>>> >>>>Without doubt, the worst oscillator I have ever seen anyone design. You >>>>are right. You are not an analog guy. >>> >>> What's wrong with it? It worked first try. >>> >>> We have surface-mount inductors in stock, many values, but no tapped >>> inductors in that range. >> >>You don't need tapped inductors. You make the feedback with tapped >>capacitors. That means capacitors in series. > > Sure. Colpitts has been around for about a century. This is a design > group. Instant hostility to ideas is easy.Instant hostility to idiotic ideas is easy. Did you know you tried to make an oscillator with inductor Q's of 20,420? Inductor reactance: 2*pi*2.5e-9*1.3e9 = 20.42 ohms You do not realize the inductor ESR defaults to 1 milliohm if it is not specified. I have told you about this many times but you consider advice to be an insult and you ignore it. The resulting Q is 20.42/1e-3 = 20,420 Where do you plan of getting inductors like that? Next problem. Have you looked at the waveform at the source pin of your oscillator? How do you plan on getting useful output from that? Again, you completely ignore helpful advice that could teach you how to go about designing a useful oscillator. The link I provided was a complete waste of time, but here it is again: https://tinyurl.com/2p9yrxmy I defy you to make a useful oscillator by ignoring these rules.
Reply by ●February 3, 20222022-02-03
Arnie Dwyer wrote:> jlarkin@highlandsniptechnology.com wrote: > >> On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spamme@not.com> >> wrote: >> >>> jlarkin@highlandsniptechnology.com wrote: >>> >>>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer <spamme@not.com> >>>> wrote: >>>> >>>>> jlarkin@highlandsniptechnology.com wrote: >>>>> >>>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>>> [...] >>>>> >>>>> Without doubt, the worst oscillator I have ever seen anyone design. You >>>>> are right. You are not an analog guy. >>>> What's wrong with it? It worked first try. >>>> >>>> We have surface-mount inductors in stock, many values, but no tapped >>>> inductors in that range. >>> You don't need tapped inductors. You make the feedback with tapped >>> capacitors. That means capacitors in series. >> Sure. Colpitts has been around for about a century. This is a design >> group. Instant hostility to ideas is easy. > > Instant hostility to idiotic ideas is easy. Did you know you tried to make > an oscillator with inductor Q's of 20,420? > > Inductor reactance: 2*pi*2.5e-9*1.3e9 = 20.42 ohms > > You do not realize the inductor ESR defaults to 1 milliohm if it is not > specified. I have told you about this many times but you consider advice to > be an insult and you ignore it. The resulting Q is > 20.42/1e-3 = 20,420 > > Where do you plan of getting inductors like that?Don't be silly. What matters is the loaded Q. And this oscillator will run just fine even with an effective Q below 10. The bare coil Q is mostly irrelevant.> > Next problem. Have you looked at the waveform at the source pin of your > oscillator? How do you plan on getting useful output from that?Many oscillator designs let the transistor current hit zero in order to limit the amplitude. Inevitably, the signal at the source ends up looking nasty, at least in the simulation. In a real circuit, it won't look nearly as bad. If you need a purer output, you can always take it from the top of the tank. Jeroen Belleman
Reply by ●February 3, 20222022-02-03
On Thursday, February 3, 2022 at 10:40:25 PM UTC+11, Arnie Dwyer wrote:> jla...@highlandsniptechnology.com wrote: > > > On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spa...@not.com> > > wrote: > > > >>jla...@highlandsniptechnology.com wrote: > >> > >>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer <spa...@not.com> > >>> wrote: > >>> > >>>>jla...@highlandsniptechnology.com wrote: > >>>> > >>>>> Not actually a Hartley, bacause the Ls are not coupled. > >>>> > >>>>[...] > >>>> > >>>>Without doubt, the worst oscillator I have ever seen anyone design. You > >>>>are right. You are not an analog guy. > >>> > >>> What's wrong with it? It worked first try. > >>> > >>> We have surface-mount inductors in stock, many values, but no tapped > >>> inductors in that range. > >> > >>You don't need tapped inductors. You make the feedback with tapped > >>capacitors. That means capacitors in series. > > > > Sure. Colpitts has been around for about a century. This is a design > > group. Instant hostility to ideas is easy. > Instant hostility to idiotic ideas is easy. Did you know you tried to make > an oscillator with inductor Q's of 20,420? > > Inductor reactance: 2*pi*2.5e-9*1.3e9 = 20.42 ohms > > You do not realize the inductor ESR defaults to 1 milliohm if it is not > specified. I have told you about this many times but you consider advice to > be an insult and you ignore it. The resulting Q is > 20.42/1e-3 = 20,420 > > Where do you plan on getting inductors like that?He doesn't like thinking about inductors - too complicated - and buys them off the shelf when he has to use them. The business of designing a special purpose transformer and getting it wound strikes him as more trouble than it can possibly be worth (though he has wound a special purpose inductor around a pencil and made a lot of fuss about the result.)> Next problem. Have you looked at the waveform at the source pin of your > oscillator? How do you plan on getting useful output from that? > > Again, you completely ignore helpful advice that could teach you how to go > about designing a useful oscillator.He's here to garner flattery, not to listen to advice, nor humiliate himself by admitting that it was useful.> The link I provided was a complete > waste of time, but here it is again: > > https://tinyurl.com/2p9yrxmyYour first inductor doesn't have any parallel capacitance which isn't all that physically realistic either.> I defy you to make a useful oscillator by ignoring these rules.John Larkin's approach to design looks like evolution in action. He does seem to come up with useful - or least marketable - circuits, but if there is a design element in the development process he doesn't seem to be willing to talk about it. -- Bill Sloman, Sydney
Reply by ●February 3, 20222022-02-03
On Thu, 3 Feb 2022 11:40:13 -0000 (UTC), Arnie Dwyer <spamme@not.com> wrote:>jlarkin@highlandsniptechnology.com wrote: > >> On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spamme@not.com> >> wrote: >> >>>jlarkin@highlandsniptechnology.com wrote: >>> >>>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer <spamme@not.com> >>>> wrote: >>>> >>>>>jlarkin@highlandsniptechnology.com wrote: >>>>> >>>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>>> >>>>>[...] >>>>> >>>>>Without doubt, the worst oscillator I have ever seen anyone design. You >>>>>are right. You are not an analog guy. >>>> >>>> What's wrong with it? It worked first try. >>>> >>>> We have surface-mount inductors in stock, many values, but no tapped >>>> inductors in that range. >>> >>>You don't need tapped inductors. You make the feedback with tapped >>>capacitors. That means capacitors in series. >> >> Sure. Colpitts has been around for about a century. This is a design >> group. Instant hostility to ideas is easy. > >Instant hostility to idiotic ideas is easy. Did you know you tried to make >an oscillator with inductor Q's of 20,420? > >Inductor reactance: 2*pi*2.5e-9*1.3e9 = 20.42 ohms > >You do not realize the inductor ESR defaults to 1 milliohm if it is not >specified. I have told you about this many times but you consider advice to >be an insult and you ignore it. The resulting Q is >20.42/1e-3 = 20,420I don't consider your advice to be an insult. But real inductor Qs are high enough that I can ignore them here; the phemt has gobs of gain. The first step of circuit design is topology.> >Where do you plan of getting inductors like that? > >Next problem. Have you looked at the waveform at the source pin of your >oscillator? How do you plan on getting useful output from that?I doubt we'd see those squiggles in real life. But we don't truly trust Spice models for things like this; As Mike say, Spice is for training your instincts. After futzing with a lot of sims, we pick the best ones and build them.> >Again, you completely ignore helpful advice that could teach you how to go >about designing a useful oscillator. The link I provided was a complete >waste of time, but here it is again: > >https://tinyurl.com/2p9yrxmy > >I defy you to make a useful oscillator by ignoring these rules.I sell lots of products with oscillators. They always work. About the only rule I respect is Conservation of Energy. This biz is full of "Rules" that are wrong. -- John Larkin Highland Technology, Inc trk 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 3, 20222022-02-03
On Friday, February 4, 2022 at 1:20:06 AM UTC+11, John Larkin wrote:> On Thu, 3 Feb 2022 11:40:13 -0000 (UTC), Arnie Dwyer <spa...@not.com> wrote: > >jla...@highlandsniptechnology.com wrote: > >> On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spa...@not.com> wrote: > >>>jla...@highlandsniptechnology.com wrote: > >>>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer <spa...@not.com> wrote: > >>>>>jla...@highlandsniptechnology.com wrote:> I doubt we'd see those squiggles in real life. But we don't truly > trust Spice models for things like this; As Mike say, Spice is for > training your instincts.Of course you aren't all that picky about modelling your components carefully either.> After futzing with a lot of sims, we pick the best ones and build them.A sim that has an inductor without any parallel capacitance may look better than one with a more realistic inductor.> >Again, you completely ignore helpful advice that could teach you how to go > >about designing a useful oscillator. The link I provided was a complete > >waste of time, but here it is again: > > > >https://tinyurl.com/2p9yrxmy > > > >I defy you to make a useful oscillator by ignoring these rules. > > I sell lots of products with oscillators. They always work. About the only rule I respect is Conservation of Energy. This biz is full of "Rules" that are wrong.If you understood the rules better, they'd look wrong a lot less often. -- Bill Sloman, Sydney
Reply by ●February 3, 20222022-02-03
John Larkin <jjlarkin@highlandtechnology.com> wrote:> On Thu, 3 Feb 2022 11:40:13 -0000 (UTC), Arnie Dwyer <spamme@not.com> > wrote: > >>jlarkin@highlandsniptechnology.com wrote: >> >>> On Wed, 2 Feb 2022 07:23:10 -0000 (UTC), Arnie Dwyer <spamme@not.com> >>> wrote: >>> >>>>jlarkin@highlandsniptechnology.com wrote: >>>> >>>>> On Wed, 2 Feb 2022 01:55:39 -0000 (UTC), Arnie Dwyer >>>>> <spamme@not.com> wrote: >>>>> >>>>>>jlarkin@highlandsniptechnology.com wrote: >>>>>> >>>>>>> Not actually a Hartley, bacause the Ls are not coupled. >>>>>> >>>>>>[...] >>>>>> >>>>>>Without doubt, the worst oscillator I have ever seen anyone design. >>>>>>You are right. You are not an analog guy. >>>>> >>>>> What's wrong with it? It worked first try. >>>>> >>>>> We have surface-mount inductors in stock, many values, but no tapped >>>>> inductors in that range. >>>> >>>>You don't need tapped inductors. You make the feedback with tapped >>>>capacitors. That means capacitors in series. >>> >>> Sure. Colpitts has been around for about a century. This is a design >>> group. Instant hostility to ideas is easy. >> >>Instant hostility to idiotic ideas is easy. Did you know you tried to >>make an oscillator with inductor Q's of 20,420? >> >>Inductor reactance: 2*pi*2.5e-9*1.3e9 = 20.42 ohms >> >>You do not realize the inductor ESR defaults to 1 milliohm if it is not >>specified. I have told you about this many times but you consider advice >>to be an insult and you ignore it. The resulting Q is 20.42/1e-3 = >>20,420 > > I don't consider your advice to be an insult. But real inductor Qs are > high enough that I can ignore them here; the phemt has gobs of gain. > The first step of circuit design is topology. > >> >>Where do you plan of getting inductors like that? >> >>Next problem. Have you looked at the waveform at the source pin of your >>oscillator? How do you plan on getting useful output from that? > > I doubt we'd see those squiggles in real life. But we don't truly > trust Spice models for things like this; As Mike say, Spice is for > training your instincts. After futzing with a lot of sims, we pick the > best ones and build them. > > >> >>Again, you completely ignore helpful advice that could teach you how to >>go about designing a useful oscillator. The link I provided was a >>complete waste of time, but here it is again: >> >>https://tinyurl.com/2p9yrxmy >> >>I defy you to make a useful oscillator by ignoring these rules. > > I sell lots of products with oscillators. They always work. About the > only rule I respect is Conservation of Energy. This biz is full of > "Rules" that are wrong.Changing the Q of the inductors to 10 has little effect. However, adding 1pf stray capacitance across each inductor converts the squiggles into distorted sine waves suitable for driving a load. Adding mutual coupling of 0.1 between the inductors will smooth the waveform even more. However, these changes turn the circuit into a conventional Hartley, which nobody uses any more. Vastly improved perfomance is obtained with a conventional Colpitts. This requires fewer inductors which are expensive and adds one capacitor which is cheaper. Congratulations. You have invented a Hartley oscillator.
Reply by ●February 3, 20222022-02-03
Jeroen Belleman <jeroen@nospam.please> wrote:> Arnie Dwyer wrote: >> jlarkin@highlandsniptechnology.com wrote:[...]>> You do not realize the inductor ESR defaults to 1 milliohm if it is not >> specified. I have told you about this many times but you consider >> advice to be an insult and you ignore it. The resulting Q is >> 20.42/1e-3 = 20,420 >> >> Where do you plan of getting inductors like that? > > Don't be silly. What matters is the loaded Q. And this oscillator > will run just fine even with an effective Q below 10. The bare > coil Q is mostly irrelevant.Ignoring the Q is plain sloppy.>> Next problem. Have you looked at the waveform at the source pin of your >> oscillator? How do you plan on getting useful output from that?> Many oscillator designs let the transistor current hit zero in order > to limit the amplitude.The waveform at the source pin is unusable. You should take a look for yourself. Most oscillators operate in class C, where the conduction angle is less than 50%. The transistor is biased off most of the time. Driving the oscillator into limiting means forward biasing the base- collector junction. This decreases the tank Q and generates unwanted harmonics. A much better option is to limit the energy fed into the tank so it equals the energy dissipated in the tank. This is normally achieved by reducing the current into the transistor.> Inevitably, the signal at the source ends up > looking nasty, at least in the simulation. In a real circuit, it won't > look nearly as bad.The signal at the source should not look nasty. JL's circuit ignores component parasitics. This makes the sim irrelevant. If the real circuit does not resemble the simulation, the simulation is bad. At the frequencies where SPICE is usable, a close correlation between actual and simulation should be possible, otherwise you are fooling yourself. The signal at the source does not have to look ugly, even in the simulation. JL's oscillator can be made to look usable by adding 1pf caps across each inductor, and adding a bit of mutual coupling to smooth it even more. However, this turns it into a Hartley, which nobody uses any more. Inductors are expensive. Changing the circut into a Colpitts gives vastly better performance and eliminates one inductor.> If you need a purer output, you can always take it > from the top of the tank.Taking the output from the top of the tank destroys the Q.> Jeroen Belleman
