It is a Wien bridge.... Sent from my iPhone > On Jan 7, 2018, at 10:33 AM, jimlux <jimlux@earthlink.net> wrote: > >> On 1/6/18 6:12 PM, Dana Whitlow wrote: >> One point about oscillator design I've not yet seen mentioned is this: the >> limiter >> must not degrade the resonator Q when in action. Hence, a pair of diodes >> connected in parallel back to back, across a shunt resonator, would be a bad >> thing to do from the perspective of low phase noise. A differential >> amplifier >> that limits by running out of current on peaks, driving a shunt resonator, >> is >> a much better way even though one pays a price in having more transistor >> noise in the circuit. >> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms >> issue except, of course, for things happening within the AGC loop's >> bandwidth. > > > That's the Wein bridge stabilized by a light bulb, popularized by Messrs Hewlett and Packard a while ago. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

You are simply correct ! Ulrich Sent from my iPhone > On Jan 7, 2018, at 11:05 AM, Arnold Tibus <arnold.tibus@gmx.de> wrote: > >> Am 07.01.2018 um 16:33 schrieb jimlux: >>> On 1/6/18 6:12 PM, Dana Whitlow wrote: >>> One point about oscillator design I've not yet seen mentioned is this: the >>> limiter >>> must not degrade the resonator Q when in action. Hence, a pair of diodes >>> connected in parallel back to back, across a shunt resonator, would be a bad >>> thing to do from the perspective of low phase noise. A differential >>> amplifier >>> that limits by running out of current on peaks, driving a shunt resonator, >>> is >>> a much better way even though one pays a price in having more transistor >>> noise in the circuit. >>> >>> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms >>> issue except, of course, for things happening within the AGC loop's >>> bandwidth. >>> >> That's the Wein bridge stabilized by a light bulb, popularized by Messrs Hewlett and Packard a while ago. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.comgents, >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > Hello everybody, excuse me please, > > but I see quite often mentioned the 'Wein bridge'. (Wein in german is 'vino' or 'wine' ;-) > Not of real technical importance, but shouldn't this not be correctly called a 'Wien bridge'? > As I know that this tricky circuit was developed by Max Wien in 1891. > Max Karl Werner Wien was a German physicist and the director of the Institute of Physics at the University of Jena at that time. > (sorry, I am a nut ;-) ) > > My best wishes for 2018 to everybody, > > Arnold, DK2WT > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

On 1/7/18 8:05 AM, Arnold Tibus wrote: > Am 07.01.2018 um 16:33 schrieb jimlux: >> On 1/6/18 6:12 PM, Dana Whitlow wrote: >>> One point about oscillator design I've not yet seen mentioned is >>> this: the >>> limiter >>> must not degrade the resonator Q when in action.  Hence, a pair of >>> diodes >>> connected in parallel back to back, across a shunt resonator, would >>> be a bad >>> thing to do from the perspective of low phase noise. A differential >>> amplifier >>> that limits by running out of current on peaks, driving a shunt >>> resonator, >>> is >>> a much better way even though one pays a price in having more transistor >>> noise in the circuit. >>> >>> I've long wondered if a very slow AGC might avoid the nonlinear >>> mechanisms >>> issue except, of course, for things happening within the AGC loop's >>> bandwidth. >> >>> >> >> That's the Wein bridge stabilized by a light bulb, popularized by >> Messrs Hewlett and Packard a while ago. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.comgents, >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > Hello everybody, excuse me please, > > but I see quite often mentioned the 'Wein bridge'. (Wein in german is > 'vino' or 'wine' ;-) > Not of real technical importance, but shouldn't this not be correctly > called a 'Wien bridge'? > As I know that this tricky circuit was developed by Max Wien in 1891. > Max Karl Werner Wien was a German physicist and the director of the > Institute of Physics at the University of Jena at that time. >  (sorry, I am a nut ;-)  ) > Ah yes. And I imagine then that the pronounciation should be in english "veen"

Hi > On Jan 7, 2018, at 12:26 PM, jimlux <jimlux@earthlink.net> wrote: > > On 1/7/18 8:05 AM, Arnold Tibus wrote: >> Am 07.01.2018 um 16:33 schrieb jimlux: >>> On 1/6/18 6:12 PM, Dana Whitlow wrote: >>>> One point about oscillator design I've not yet seen mentioned is this: the >>>> limiter >>>> must not degrade the resonator Q when in action. Hence, a pair of diodes >>>> connected in parallel back to back, across a shunt resonator, would be a bad >>>> thing to do from the perspective of low phase noise. A differential >>>> amplifier >>>> that limits by running out of current on peaks, driving a shunt resonator, >>>> is >>>> a much better way even though one pays a price in having more transistor >>>> noise in the circuit. >>>> >>>> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms >>>> issue except, of course, for things happening within the AGC loop's >>>> bandwidth. >>> >>>> >>> >>> That's the Wein bridge stabilized by a light bulb, popularized by Messrs Hewlett and Packard a while ago. >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.comgents, >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> Hello everybody, excuse me please, >> but I see quite often mentioned the 'Wein bridge'. (Wein in german is 'vino' or 'wine' ;-) >> Not of real technical importance, but shouldn't this not be correctly called a 'Wien bridge'? >> As I know that this tricky circuit was developed by Max Wien in 1891. >> Max Karl Werner Wien was a German physicist and the director of the Institute of Physics at the University of Jena at that time. >> (sorry, I am a nut ;-) ) > > > > > > Ah yes. And I imagine then that the pronounciation should be in english “veen" This time of year, it’s the word on the label right after the term Gluh. I tend to never / ever get that one right either. It always comes out Glugh …. can’t think of why :) The Wien bridge is a very “low Q” resonator approach. It will give you amazingly low distortion (low harmonics) at the same time it does pretty poor amplitude and phase noise. Bob > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

I`m looking at the circuit of an H/P10544 oscillator - can anybody confirm, please, if the H'P transistor types : 53-20, and 54-215 have commercial equivalents? Thankyou.................................................... ............................................................ ............................................................ ...............................................Don. On Mon, Jan 8, 2018 at 1:02 AM, donald collie <donaldbcollie@gmail.com> wrote: > Does any limiter, soft or hard, [and perhaps any nonlinearity of power > term 3 or greater in the amplifier of an oscillator] cause the "baseband > 1/f noise to translate up to the resonator frequency [a form of > crossmodulation]?. I wonder this because > phase noise vs freq plots look a bit like the 1/f plots of a resistor, or > active device, or power supply. Ceramic caps, and resonators [I`m thinking > of quartz crystals] don`t pass much DC, and as I understand it, 1/f noise > is associated with dc passing through resistors, or semiconductors. So the > best way to go might be to have a very linear amplifier, which exhibits > very low noise [perhaps 150dB below the operating level], with an AGC loop, > that sets the operating levela little below the level at which the amp > starts to clip - this could be done with a thermistor to avoid the AGC loop > altering the [optimised] operating conditions of the amp. Alternatively you > might be able to use a tetrode device like a dual gate MOSFET, and apply > the AGC to the second gate. Thus you could keep the extremely linear amp > extremely linear. [150dB below 1Volt RMS is 0.032uV RMS]. > Cheers!..................................................... > ............................................................ > .......................................................Don ZL4GX > > > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free. > www.avg.com > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_3433364989741243603_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > On Sun, Jan 7, 2018 at 3:12 PM, Dana Whitlow <k8yumdoober@gmail.com> > wrote: > >> One point about oscillator design I've not yet seen mentioned is this: the >> limiter >> must not degrade the resonator Q when in action. Hence, a pair of diodes >> connected in parallel back to back, across a shunt resonator, would be a >> bad >> thing to do from the perspective of low phase noise. A differential >> amplifier >> that limits by running out of current on peaks, driving a shunt resonator, >> is >> a much better way even though one pays a price in having more transistor >> noise in the circuit. >> >> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms >> issue except, of course, for things happening within the AGC loop's >> bandwidth. >> Is anybody reading this aware of what the truth really is? >> >> Dana >> >> >> On Sat, Jan 6, 2018 at 4:29 PM, Magnus Danielson < >> magnus@rubidium.dyndns.org >> > wrote: >> >> > >> > >> > On 01/06/2018 10:31 PM, Joseph Gwinn wrote: >> > >> ------------------------------ >> > >> >> > >> Message: 2 >> > >> Date: Sat, 6 Jan 2018 09:19:31 -0500 >> > >> From: Bob kb8tq <kb8tq@n1k.org> >> > >> To: Discussion of precise time and frequency measurement >> > >> <time-nuts@febo.com> >> > >> Subject: Re: [time-nuts] AM vs PM noise of signal sources >> > >> Message-ID: <DDEF34DD-AD21-44C6-9612-D877881078E5@n1k.org> >> > >> Content-Type: text/plain; charset=utf-8 >> > >> >> > >> Hi >> > >> >> > >> The key point missing is the fact that any real oscillator must have >> > >> a limiter >> > >> in the loop. Otherwise it will “create one” by going over the max >> > >> output of this or >> > >> that amplifier. To the degree that the limiter has issues (limits >> > >> poorly) you will get >> > >> AM noise. >> > > >> > > Hmm. Not strictly true. One can also use an AGC loop, like a wein >> > > bridge oscillator. That said, some kind of softish limiter is >> commonly >> > > used. >> > >> > Regardless what non-linear mechanism in play, this remains a non-linear >> > mechanism that achieves the goal. Choose wisely. >> > >> > Cheers, >> > Magnus >> > _______________________________________________ >> > time-nuts mailing list -- time-nuts@febo.com >> > To unsubscribe, go to https://www.febo.com/cgi-bin/ >> > mailman/listinfo/time-nuts >> > and follow the instructions there. >> > >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/m >> ailman/listinfo/time-nuts >> and follow the instructions there. >> > >

Am 07.01.2018 um 17:05 schrieb Arnold Tibus: > > but I see quite often mentioned the 'Wein bridge'. (Wein in german is > 'vino' or 'wine' ;-) > Not of real technical importance, but shouldn't this not be correctly > called a 'Wien bridge'? > As I know that this tricky circuit was developed by Max Wien in 1891. > Max Karl Werner Wien was a German physicist and the director of the > Institute of Physics at the University of Jena at that time. >  (sorry, I am a nut ;-)  ) > He shares that fate with a certain Mr. Seimens and the famous Oscar Meyer Weiner. That must be a German->American sound shift, some kind of extension to Grimm's law. There also was a Mr. Hamming, but there never was a Mr. Hanning, at least not in the business of weighting contents of time series. That guy with the window function was one Mr. Julius von Hann, an Austrian Meteorologist. It is therefore the Hann window. <    https://en.wikipedia.org/wiki/Julius_von_Hann    > cheers, Gerhard

Wien bridge and bridged T oscillators often use a thermistor [lamp] to set the amplitude below saturation, for low distortion, but i`ve seen the diode AGC method used. Conversely, you could use a thermistor to set the output of a crystal or L/C oscillator. One other method seems to be to let the oscillator limit somehow, and then rely on the filtering action of the resonator to purify the output. Is this shutting the barn door, after the horse has egreased, though - especially with close in phase noise, which doesn`t get filtered as much?. One possible advantage of the thermistor approach would be that the gain can be reduced without changing the active device`s operating point, which may have been chosen after conciddering number of factors : Oscillator amplitude, best phase noise , linearity. etc. Thankyou Jeff for pointing out that for best results, maximum output is not always sought. Looking at my H'P 10544A circuit I see a slow, diode AGC, and a single 2N4125 [?] oscillator transistor with AGC applied to its emitter. I guess that the voltage gain through the crystal means that the oscillator produces the expected output with this transistor loafing along, causing the PM mechanism[s] in this transistor not to be as large as they might well be if the oscillator was limiting. Cheers!...............................................................Don C. P.S.: I`m not learned, just enthusiastic ;-) <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#m_5189967835349033426_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Mon, Jan 8, 2018 at 3:08 PM, Gerhard Hoffmann <dk4xp@arcor.de> wrote: > > > Am 07.01.2018 um 17:05 schrieb Arnold Tibus: > >> >> but I see quite often mentioned the 'Wein bridge'. (Wein in german is >> 'vino' or 'wine' ;-) >> Not of real technical importance, but shouldn't this not be correctly >> called a 'Wien bridge'? >> As I know that this tricky circuit was developed by Max Wien in 1891. >> Max Karl Werner Wien was a German physicist and the director of the >> Institute of Physics at the University of Jena at that time. >> (sorry, I am a nut ;-) ) >> >> > He shares that fate with a certain Mr. Seimens and the famous Oscar Meyer > Weiner. > That must be a German->American sound shift, some kind of extension to > Grimm's law. > > There also was a Mr. Hamming, but there never was a Mr. Hanning, at least > not > in the business of weighting contents of time series. > > That guy with the window function was one Mr. Julius von Hann, an > Austrian Meteorologist. It is therefore the Hann window. > > < https://en.wikipedia.org/wiki/Julius_von_Hann > > > cheers, Gerhard > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instructions there. >