Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
Ham op:
Just drew the circuit of a xtal in the feedback of a high precision op amp circuit... hmmm, could be colpitts--but can't see the resemblance... Just drew the circuit of an xtal chucked in the feedback line of a set of logic gates... hmmm, that could be colpitts too, but again, can't see the resemblance... John "Ham op" wrote in message ... John Smith wrote: Wes: Those osc are a thing of the past... Bring a junk am broadcast radio near your computer, you will hear literal dozens (well, a bunch anyway!) of osc's freqs going on there, probably not one being generated by a colpitts, hartley or pierce osc circuit... And, with the proper processing, all those waves could be a sine... John Each of those oscillators use a crystal for frequency and stability! Each of those oscillators uses positive feedback so that it oscillates. Draw the equivalent circuit of those oscillators and you will find the COLPITTS circuit !!!! I wonder if you are confusing the Coplitts/Hartley topography with the old VFO which were/are variable tuned [Colpitts/Hartley] oscillators. Every digital frequency synthesizer uses a Colpitts oscillator as the reference oscillator, at a fixed frequency, and the variable oscillator is digitally phase locked to it. The basic Physics and governing laws for oscillators has not changed. |
#2
|
|||
|
|||
On Fri, 29 Jul 2005 12:33:53 -0700, "John Smith"
wrote: Ham op: Just drew the circuit of a xtal in the feedback of a high precision op amp circuit... hmmm, could be colpitts--but can't see the resemblance... Just drew the circuit of an xtal chucked in the feedback line of a set of logic gates... hmmm, that could be colpitts too, but again, can't see the resemblance... Draw a transistor (FET, or triode) with a capacitor from collector (drain, plate) to emitter (source, cathode), an inductor from collector to base (gate, grid), and a capacitor from base to emitter. Ground the emitter and everything connected to it and take the output from the collector. You have a Pierce. Replace the inductor with a crystal and you have a Pierce oscillator with the crystal operating in the anti-resonant mode. Ground the collector and everything connected to it and take the output from the emitter. You have a Colpitts. Replace the inductor with a crystal and you have a Colpitts oscillator with the crystal operating in the anti-resonant mode. Insert a crystal between the emitter and the two capacitors connected to it and take the output from the emitter and you have a crystal oscillator operating at series (or overtone) resonance. Stick a varactor in there someplace and you have a VCO or VCXO. Clapp, Vacker, Franklin, Butler.... they are all just variations on an old theme. |
#3
|
|||
|
|||
Wes:
Of course there are millions, if not billions of 'em in my computer, encased in the chips there, but having viewed many, many spec sheets and diagrams of the internal geometry of the chips, can't say I would really bet there is a colpitts commanding the freq of the bus in my computer, nor the daughter boards in their... Now you might be right, it is just an argument I must defer from, since reliable data one way or another cannot be obtained without expending more effort than I am prepared to expend... I'll even grant you a win by default--the argument simply is not deserving of my time, and anyone with access to the internet can look at a diagram depicting components used in the clocks of "modern circuits." John "Wes Stewart" wrote in message ... On Fri, 29 Jul 2005 12:33:53 -0700, "John Smith" wrote: Ham op: Just drew the circuit of a xtal in the feedback of a high precision op amp circuit... hmmm, could be colpitts--but can't see the resemblance... Just drew the circuit of an xtal chucked in the feedback line of a set of logic gates... hmmm, that could be colpitts too, but again, can't see the resemblance... Draw a transistor (FET, or triode) with a capacitor from collector (drain, plate) to emitter (source, cathode), an inductor from collector to base (gate, grid), and a capacitor from base to emitter. Ground the emitter and everything connected to it and take the output from the collector. You have a Pierce. Replace the inductor with a crystal and you have a Pierce oscillator with the crystal operating in the anti-resonant mode. Ground the collector and everything connected to it and take the output from the emitter. You have a Colpitts. Replace the inductor with a crystal and you have a Colpitts oscillator with the crystal operating in the anti-resonant mode. Insert a crystal between the emitter and the two capacitors connected to it and take the output from the emitter and you have a crystal oscillator operating at series (or overtone) resonance. Stick a varactor in there someplace and you have a VCO or VCXO. Clapp, Vacker, Franklin, Butler.... they are all just variations on an old theme. |
#4
|
|||
|
|||
On Fri, 29 Jul 2005 16:47:39 -0700, "John Smith"
wrote: Wes: Of course there are millions, if not billions of 'em in my computer, encased in the chips there, but having viewed many, many spec sheets and diagrams of the internal geometry of the chips, can't say I would really bet there is a colpitts commanding the freq of the bus in my computer, nor the daughter boards in their...(sic) Well, there is usually only one oscillator, not billions, and I'm sure that I said "Pierce", not Colpitts. Now you might be right, it is just an argument I must defer from, since reliable data one way or another cannot be obtained without expending more effort than I am prepared to expend... I'll even grant you a win by default--the argument simply is not deserving of my time, and anyone with access to the internet can look at a diagram depicting components used in the clocks of "modern circuits." I just did a little "data mining." Out of the last 188 posts in this forum, you made 47 of them, or 25%. Perhaps if you "expended some of the effort" that you waste writing every fourth post you would have a little time to actually research what you're saying -before- you write about it. Just a thought. BTW, I wasn't trying to "win", I was trying to correct the insane idea that knowledge of "old time" oscillators is unworthy of study when talking about "modern" radios. The fact that this belief exists is proof positive that questions about these things should remain in the amateur exams. But expending effort to learn the basics is too much effort for "modern" hams. Plus the applicant's self-esteem might suffer if he has to gain a little knowledge of electronics, antennas, transmission lines, good operating practice and Morse code, so I suppose the FCC should just issue licenses to anyone who makes a request. "Wes Stewart" wrote in message .. . On Fri, 29 Jul 2005 12:33:53 -0700, "John Smith" wrote: Ham op: Just drew the circuit of a xtal in the feedback of a high precision op amp circuit... hmmm, could be colpitts--but can't see the resemblance... Just drew the circuit of an xtal chucked in the feedback line of a set of logic gates... hmmm, that could be colpitts too, but again, can't see the resemblance... Draw a transistor (FET, or triode) with a capacitor from collector (drain, plate) to emitter (source, cathode), an inductor from collector to base (gate, grid), and a capacitor from base to emitter. Ground the emitter and everything connected to it and take the output from the collector. You have a Pierce. Replace the inductor with a crystal and you have a Pierce oscillator with the crystal operating in the anti-resonant mode. Ground the collector and everything connected to it and take the output from the emitter. You have a Colpitts. Replace the inductor with a crystal and you have a Colpitts oscillator with the crystal operating in the anti-resonant mode. Insert a crystal between the emitter and the two capacitors connected to it and take the output from the emitter and you have a crystal oscillator operating at series (or overtone) resonance. Stick a varactor in there someplace and you have a VCO or VCXO. Clapp, Vacker, Franklin, Butler.... they are all just variations on an old theme. |
#5
|
|||
|
|||
My sentiments exactly. Thanks for saying it Wes.
73, Larry, W0QE Wes Stewart wrote: I just did a little "data mining." Out of the last 188 posts in this forum, you made 47 of them, or 25%. Perhaps if you "expended some of the effort" that you waste writing every fourth post you would have a little time to actually research what you're saying -before- you write about it. Just a thought. |
#6
|
|||
|
|||
Wes:
I had dropped the all important word "transistors" in reference to "millions... billions". I never dreamed anyone could be mistaken that someone was claiming that many osc's in a computer, but you never can tell about the CB'ers--they might think so! Here is a mess of stuff on clocks, osc's which are generally used in digital equip these days (and this is stuff I am used to, a decade old or better technology, probably two decades!): .... it should be apparent mr. pierce is not here in (at least most) of this material: Simple logic gate oscillator: http://www.it.lth.se/digp/PDF_files/oscillators.pdf Design of op amp oscillators: http://focus.ti.com/lit/an/slyt164/slyt164.pdf CMOS oscillator: http://www.ee.washington.edu/circuit...ASCIISCHEM_004 Clock divider: http://www.ee.washington.edu/circuit...s/clockdiv.txt clock doubler: http://www.ee.washington.edu/circuit...ckdoubler.html square wave to sine converter: http://www.ee.washington.edu/circuit...quare2sine.txt pdf on digital oscillators: http://online.physics.uiuc.edu/cours..._TTL_Logic.pdf Computer project, using 7404 as a clock: https://www.cs.tcd.ie/Jeremy.Jones/3d2/3d2project.htm John "Wes Stewart" wrote in message ... On Fri, 29 Jul 2005 16:47:39 -0700, "John Smith" wrote: Wes: Of course there are millions, if not billions of 'em in my computer, encased in the chips there, but having viewed many, many spec sheets and diagrams of the internal geometry of the chips, can't say I would really bet there is a colpitts commanding the freq of the bus in my computer, nor the daughter boards in their...(sic) Well, there is usually only one oscillator, not billions, and I'm sure that I said "Pierce", not Colpitts. Now you might be right, it is just an argument I must defer from, since reliable data one way or another cannot be obtained without expending more effort than I am prepared to expend... I'll even grant you a win by default--the argument simply is not deserving of my time, and anyone with access to the internet can look at a diagram depicting components used in the clocks of "modern circuits." I just did a little "data mining." Out of the last 188 posts in this forum, you made 47 of them, or 25%. Perhaps if you "expended some of the effort" that you waste writing every fourth post you would have a little time to actually research what you're saying -before- you write about it. Just a thought. BTW, I wasn't trying to "win", I was trying to correct the insane idea that knowledge of "old time" oscillators is unworthy of study when talking about "modern" radios. The fact that this belief exists is proof positive that questions about these things should remain in the amateur exams. But expending effort to learn the basics is too much effort for "modern" hams. Plus the applicant's self-esteem might suffer if he has to gain a little knowledge of electronics, antennas, transmission lines, good operating practice and Morse code, so I suppose the FCC should just issue licenses to anyone who makes a request. "Wes Stewart" wrote in message . .. On Fri, 29 Jul 2005 12:33:53 -0700, "John Smith" wrote: Ham op: Just drew the circuit of a xtal in the feedback of a high precision op amp circuit... hmmm, could be colpitts--but can't see the resemblance... Just drew the circuit of an xtal chucked in the feedback line of a set of logic gates... hmmm, that could be colpitts too, but again, can't see the resemblance... Draw a transistor (FET, or triode) with a capacitor from collector (drain, plate) to emitter (source, cathode), an inductor from collector to base (gate, grid), and a capacitor from base to emitter. Ground the emitter and everything connected to it and take the output from the collector. You have a Pierce. Replace the inductor with a crystal and you have a Pierce oscillator with the crystal operating in the anti-resonant mode. Ground the collector and everything connected to it and take the output from the emitter. You have a Colpitts. Replace the inductor with a crystal and you have a Colpitts oscillator with the crystal operating in the anti-resonant mode. Insert a crystal between the emitter and the two capacitors connected to it and take the output from the emitter and you have a crystal oscillator operating at series (or overtone) resonance. Stick a varactor in there someplace and you have a VCO or VCXO. Clapp, Vacker, Franklin, Butler.... they are all just variations on an old theme. |
#7
|
|||
|
|||
John Smith wrote:
I had dropped the all important word "transistors" in reference to "millions... billions". I never dreamed anyone could be mistaken that someone was claiming that many osc's in a computer, but you never can tell about the CB'ers--they might think so! How many oscillators are there if you include quantum oscillators? :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#8
|
|||
|
|||
Cecil:
Good point, it is going on in there... I think of 'em more as "quantum white noise generators." John "Cecil Moore" wrote in message ... John Smith wrote: I had dropped the all important word "transistors" in reference to "millions... billions". I never dreamed anyone could be mistaken that someone was claiming that many osc's in a computer, but you never can tell about the CB'ers--they might think so! How many oscillators are there if you include quantum oscillators? :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#9
|
|||
|
|||
On Fri, 29 Jul 2005 20:04:13 -0700, "John Smith"
wrote: Wes: I had dropped the all important word "transistors" in reference to "millions... billions". I never dreamed anyone could be mistaken that someone was claiming that many osc's in a computer, but you never can tell about the CB'ers--they might think so! Here is a mess of stuff on clocks, osc's which are generally used in digital equip these days (and this is stuff I am used to, a decade old or better technology, probably two decades!): A mess indeed. ... it should be apparent mr. pierce is not here in (at least most) of this material: Well, he's he http://www.mtron.com/pdf/eng_notes.pdf (See Figure 8 and associated text.) http://www.statek.com/new/pdf/tn30.pdf http://www.statek.com/new/pdf/tn31.pdf Simple logic gate oscillator: http://www.it.lth.se/digp/PDF_files/oscillators.pdf Thanks for making my point! "A better oscillator using inverter gates is given in Figure 2." (This is a Pierce.) Design of op amp oscillators: http://focus.ti.com/lit/an/slyt164/slyt164.pdf Does not apply. Earlier I said, "All sine wave oscillators, LC or crystal, are basically the same circuit with the only variable being the location of the rf common point." These are not LC or crystal oscillators. The only place you might find one of these in a modern radio is in the sidetone oscillator. CMOS oscillator: http://www.ee.washington.edu/circuit...ASCIISCHEM_004 Tinker Toy Clock divider: http://www.ee.washington.edu/circuit...s/clockdiv.txt Not an oscillator. You too busy writing to actually look at your references? clock doubler: http://www.ee.washington.edu/circuit...ckdoubler.html Op cit. square wave to sine converter: http://www.ee.washington.edu/circuit...quare2sine.txt Op cit. pdf on digital oscillators: http://online.physics.uiuc.edu/cours..._TTL_Logic.pdf This is a college course? Computer project, using 7404 as a clock: https://www.cs.tcd.ie/Jeremy.Jones/3d2/3d2project.htm Clearly, you didn't read this one. |
#10
|
|||
|
|||
Wes:
All of that exists on just a single chip these days, it is possible to have an osc chip which is usable from 1Mhz-to-1Ghz and puts out an acceptable sine... .... or so my son informs me. I took his word for it... the world has began to pass me by John "Wes Stewart" wrote in message ... On Fri, 29 Jul 2005 20:04:13 -0700, "John Smith" wrote: Wes: I had dropped the all important word "transistors" in reference to "millions... billions". I never dreamed anyone could be mistaken that someone was claiming that many osc's in a computer, but you never can tell about the CB'ers--they might think so! Here is a mess of stuff on clocks, osc's which are generally used in digital equip these days (and this is stuff I am used to, a decade old or better technology, probably two decades!): A mess indeed. ... it should be apparent mr. pierce is not here in (at least most) of this material: Well, he's he http://www.mtron.com/pdf/eng_notes.pdf (See Figure 8 and associated text.) http://www.statek.com/new/pdf/tn30.pdf http://www.statek.com/new/pdf/tn31.pdf Simple logic gate oscillator: http://www.it.lth.se/digp/PDF_files/oscillators.pdf Thanks for making my point! "A better oscillator using inverter gates is given in Figure 2." (This is a Pierce.) Design of op amp oscillators: http://focus.ti.com/lit/an/slyt164/slyt164.pdf Does not apply. Earlier I said, "All sine wave oscillators, LC or crystal, are basically the same circuit with the only variable being the location of the rf common point." These are not LC or crystal oscillators. The only place you might find one of these in a modern radio is in the sidetone oscillator. CMOS oscillator: http://www.ee.washington.edu/circuit...ASCIISCHEM_004 Tinker Toy Clock divider: http://www.ee.washington.edu/circuit...s/clockdiv.txt Not an oscillator. You too busy writing to actually look at your references? clock doubler: http://www.ee.washington.edu/circuit...ckdoubler.html Op cit. square wave to sine converter: http://www.ee.washington.edu/circuit...quare2sine.txt Op cit. pdf on digital oscillators: http://online.physics.uiuc.edu/cours..._TTL_Logic.pdf This is a college course? Computer project, using 7404 as a clock: https://www.cs.tcd.ie/Jeremy.Jones/3d2/3d2project.htm Clearly, you didn't read this one. |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Question pools and answers... | Policy | |||
FCC Morse testing at 16 and 20 WPM | Policy | |||
New Candidate for 'Youngest Extra' | Policy | |||
New ARRL Proposal | Policy | |||
Low reenlistment rate | Policy |