Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/29/15 7:19 PM, Alex Pummer wrote: Hi Bob, go to your local city library get membership[ here in California it is free] , and ask them to get from the university library, it will take some time than they cal you the your stuff is there, you could have it for four weeks if you need you could extend it for an other four weeks, the engineering library of the university of Berkeley is open to everybody, you can not take it out without additional formality, but you could read, copy, scan it there, I assume that works similarly in your state/ city/ university library, If you have a specific title, let me know, it will not happen right away, since I am working on five projects [for clients] also I am [life] member of the IEEE, where is not everything free any more, but people are reasonable 73 As a Californian, I thought similarly.. all the UC libraries are open to the public and you can get free access to online resources (e.g. IEEE Xplore) via free public workstations; although printing stuff costs money. There might be visiting hour restrictions for the general public (no showing up at 3 AM), and most of them do require some kind of photo ID. However, a bit of casual browsing shows that this is decidedly NOT the case in other states. The Ohio State University, as far as I can tell, requires you to be a member of Friends of the Library, which is not free. It was unclear whether free access to Univ of Washington libraries includes online access (on-site). Fascinating. Local public libraries vary (even in California) on their interlibrary loan/ability to request copies of articles. It depends on local budgets and politics. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On Thu, 27 Aug 2015 21:14:09 -0700 Jim Lux jim...@earthlink.net wrote: I don’t see anything on a quick Google search that actually give the Beckman constants. there's some C code out there that models AT (and also other cuts).. I'll see if I can find it. I found it in a PhD dissertation on designing temperature compensation neworks, as I recall. It's not necessarily reality, but it's a model that you could probably use to predict a range of variations. I would be interested in the c code and the dissertation. Attila Kinali -- I must not become metastable. Metastability is the mind-killer. Metastability is the little-death that brings total obliteration. I will face my metastability. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the metastability has gone there will be nothing. Only I will remain. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Hi On Aug 29, 2015, at 9:25 AM, Attila Kinali att...@kinali.ch wrote: On Fri, 28 Aug 2015 11:29:21 -0400 Bob Camp kb...@n1k.org wrote: there's some C code out there that models AT (and also other cuts).. I'll see if I can find it. I found it in a PhD dissertation on designing temperature compensation neworks, as I recall. The formulas and everything *are* out there. Last time I used them I pulled them out of IEEE papers. Since I don’t have access to them at home, (and suspect most of us are in that boat) - citing one didn’t seem like a useful thing to do. There are a bunch of fiddly little things about the constants used that vary a bit from paper to paper. Since those variations are almost all in the “past what you can measure” range for the raw quarts, it’s not real easy to work out who is right and who is wrong. There are at least 4 or 5 people on this mailinglist who have access to IEEE that i know about. One can get access to IEEE (springer and others) by using the library of a nearby technical university, or one that has a strong engineering department. …… or by begging … :) The nearest university that has a reasonable library is about a 6 hour round trip drive. That by its self is not the main problem. I’m not going to blend in as a “typical looking student” if I start wandering around poking at things. I’ve already have empirical evidence that there is about a 90% chance of getting asked “may I see your ID?” as I walk through the door. Fortunately that was back a bit when I *did* have an ID. Yes I could sign up for another course and remedy that situation. Yes there may be other universities with more open policies. I have not found one around here. Bob Alternatively, one can always send a mail to the author. Most are quite glad to hand out their papers. Of course, asking is always a good idea, no matter whom ;-) Attila Kinali -- I must not become metastable. Metastability is the mind-killer. Metastability is the little-death that brings total obliteration. I will face my metastability. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the metastability has gone there will be nothing. Only I will remain. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On Fri, 28 Aug 2015 11:29:21 -0400 Bob Camp kb...@n1k.org wrote: there's some C code out there that models AT (and also other cuts).. I'll see if I can find it. I found it in a PhD dissertation on designing temperature compensation neworks, as I recall. The formulas and everything *are* out there. Last time I used them I pulled them out of IEEE papers. Since I don’t have access to them at home, (and suspect most of us are in that boat) - citing one didn’t seem like a useful thing to do. There are a bunch of fiddly little things about the constants used that vary a bit from paper to paper. Since those variations are almost all in the “past what you can measure” range for the raw quarts, it’s not real easy to work out who is right and who is wrong. There are at least 4 or 5 people on this mailinglist who have access to IEEE that i know about. One can get access to IEEE (springer and others) by using the library of a nearby technical university, or one that has a strong engineering department. Alternatively, one can always send a mail to the author. Most are quite glad to hand out their papers. Of course, asking is always a good idea, no matter whom ;-) Attila Kinali -- I must not become metastable. Metastability is the mind-killer. Metastability is the little-death that brings total obliteration. I will face my metastability. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the metastability has gone there will be nothing. Only I will remain. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/27/15 4:46 PM, Bob Camp wrote: Hi On Aug 27, 2015, at 3:58 AM, Hal Murray hmur...@megapathdsl.net wrote: kb...@n1k.org said: Is there anything fundamental about SC that forces the turn over temperature to be high? Simple answer yes. More complicated answer : that depends. The crystal curve on an AT or an IT centers roughly at room temperature. When you fiddle the angles to get a stress compensated blank, that center point moves up to the 90 to 100 C range. Thanks. I guess I thought there was an extra degree of freedom so you could pick the turn over temperature. Life would be so much simpler if that was true …. There are indeed a range of cuts you could make. Working out the in’s and outs of any one of them is a megabuck sort of endeavor. You can predict that this or that will happen. That only gets you just so far. There are a lot of fine details that you can only find out by experiment. The graph at the bottom of this URL http://www.4timing.com/techcrystal.htm shows that there are actually 3 turn over temperatures. The Beckman graph at the bottom of that page shows a number of curves that have no turnover (those below 0 angle) . For the ones that do have a turnover, each one has an upper turn and a lower turn. The magic point in the middle that they all go through is generally called the inflection temperature. Lots of make your head hurt info at: http://www.ieee-uffc.org/frequency-control/learning/fc_conqtz2.html I don’t see anything on a quick Google search that actually give the Beckman constants. there's some C code out there that models AT (and also other cuts).. I'll see if I can find it. I found it in a PhD dissertation on designing temperature compensation neworks, as I recall. It's not necessarily reality, but it's a model that you could probably use to predict a range of variations. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Hi On Aug 28, 2015, at 12:14 AM, Jim Lux jim...@earthlink.net wrote: On 8/27/15 4:46 PM, Bob Camp wrote: Hi On Aug 27, 2015, at 3:58 AM, Hal Murray hmur...@megapathdsl.net wrote: kb...@n1k.org said: Is there anything fundamental about SC that forces the turn over temperature to be high? Simple answer yes. More complicated answer : that depends. The crystal curve on an AT or an IT centers roughly at room temperature. When you fiddle the angles to get a stress compensated blank, that center point moves up to the 90 to 100 C range. Thanks. I guess I thought there was an extra degree of freedom so you could pick the turn over temperature. Life would be so much simpler if that was true …. There are indeed a range of cuts you could make. Working out the in’s and outs of any one of them is a megabuck sort of endeavor. You can predict that this or that will happen. That only gets you just so far. There are a lot of fine details that you can only find out by experiment. The graph at the bottom of this URL http://www.4timing.com/techcrystal.htm shows that there are actually 3 turn over temperatures. The Beckman graph at the bottom of that page shows a number of curves that have no turnover (those below 0 angle) . For the ones that do have a turnover, each one has an upper turn and a lower turn. The magic point in the middle that they all go through is generally called the inflection temperature. Lots of make your head hurt info at: http://www.ieee-uffc.org/frequency-control/learning/fc_conqtz2.html I don’t see anything on a quick Google search that actually give the Beckman constants. there's some C code out there that models AT (and also other cuts).. I'll see if I can find it. I found it in a PhD dissertation on designing temperature compensation neworks, as I recall. The formulas and everything *are* out there. Last time I used them I pulled them out of IEEE papers. Since I don’t have access to them at home, (and suspect most of us are in that boat) - citing one didn’t seem like a useful thing to do. There are a bunch of fiddly little things about the constants used that vary a bit from paper to paper. Since those variations are almost all in the “past what you can measure” range for the raw quarts, it’s not real easy to work out who is right and who is wrong. Bob It's not necessarily reality, but it's a model that you could probably use to predict a range of variations. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
You might start with Leeson's equation to calculate the resonator Q that you need to get the phase noise you desire. Overtone resonators have higher Q, but they are too stiff to keep on frequency (with a reactive tuning network) under conditions in which the resonator is exposed to any practical range of (ambient) temperatures. Said another way, to get the phase noise you desire, you may need a Q that can only be achieved with an overtone resonator that cannot be brought/kept on frequency except by keeping its temperature stable (which needs to be above any expected ambient). There is a lot of good material on this topic at http://www.ieee-uffc.org/publications/books/index.asp If you can afford the complexity and power of synthesizing the desired frequency (with a DDS, perhaps) from the overtone resonator you could absorb the resonator inaccuracy with tuning commands that you send to the DDS. Mike -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Lux Sent: Wednesday, August 26, 2015 2:24 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] looking for SMT oscillator SC cut, with no oven For a project at work, I'm looking for a good close in phase noise oscillator (better than -100dBc@ 10Hz, -120dBc would be nice) at 100 MHz in a SMT form factor. But it doesn't need good temperature stability. There's tons of SMT OCXOs out there with reasonably good performance, but they draw watts. My application is actually quite temperature stable already AND I have an external reference to measure against. Most of the lower powered oscillator modules are TCXO, and have, maybe, -80dBc at 10MHz. I guess we could go to a discrete design with a crystal and amplifier, but a little clock module would be a simpler solution. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
kb...@n1k.org said: Is there anything fundamental about SC that forces the turn over temperature to be high? Simple answer yes. More complicated answer : that depends. The crystal curve on an AT or an IT centers roughly at room temperature. When you fiddle the angles to get a stress compensated blank, that center point moves up to the 90 to 100 C range. Thanks. I guess I thought there was an extra degree of freedom so you could pick the turn over temperature. The graph at the bottom of this URL http://www.4timing.com/techcrystal.htm shows that there are actually 3 turn over temperatures. Do AT crystals used in ovens take advantage of the UTP? -- So we are just lucky that an AT cut works well at a convenient temperature and that an SC cut works well with an oven. A life form on some other star might not be so lucky. -- These are my opinions. I hate spam. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Hi On Aug 26, 2015, at 7:28 PM, Hal Murray hmur...@megapathdsl.net wrote: dk...@arcor.de said: SC requires high temperature, that does not go together well with SMD and low power. Is there anything fundamental about SC that forces the turn over temperature to be high? Simple answer yes. More complicated answer : that depends. The crystal curve on an AT or an IT centers roughly at room temperature. When you fiddle the angles to get a stress compensated blank, that center point moves up to the 90 to 100 C range. To get a turn down around room, you are looking at something that is 70C away from the center of the curve. Think of a normal AT that is operating around -40C. The analogy is not perfect, but it is close enough. The crystal is moving a lot if it has a turn that far off center. Now for the more complicated part. Depending on exactly what you mean by SC, the angles that go into the blank can be fiddled a bit. You get something that has a label like “modified SC’ on it. It no longer is stress compensated. It’s still pretty good. You can bump the center of the curves up or down 10 or 20 degrees and still be “close” by some definition. The further you go, the more elastic your definition needs to be. Even with some fiddling, you still have a room temperature crystal with some major temperature slopes inside the operating range. You do *not* want to let that crystal see a draft :) Indeed if you move the phase noise limit down to 1 Hz and below, the thermal noise in a typical room will be your dominant noise source. Bob Or is is something like SC is only used in ovens and they have to be higher than ambient so nobody ever makes one at the magic angle that would give a lower turn over temp. -- These are my opinions. I hate spam. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/26/15 4:46 PM, Alex Pummer wrote: But if he needs 100dBc at 10Hz that is Wenzel's stronghold [https://twitter.com/ultralownoise] look that: http://www.wenzel.com/wp-content/parts/501-04517.pdf Yep.. got one of those sitting on my desk (or one that's very similar).. but it's a 2x2 block that draws many watts.. I want something that is 0.5x0.5 and draws 100-200 milliwatts or so. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Hi On Aug 27, 2015, at 3:58 AM, Hal Murray hmur...@megapathdsl.net wrote: kb...@n1k.org said: Is there anything fundamental about SC that forces the turn over temperature to be high? Simple answer yes. More complicated answer : that depends. The crystal curve on an AT or an IT centers roughly at room temperature. When you fiddle the angles to get a stress compensated blank, that center point moves up to the 90 to 100 C range. Thanks. I guess I thought there was an extra degree of freedom so you could pick the turn over temperature. Life would be so much simpler if that was true …. There are indeed a range of cuts you could make. Working out the in’s and outs of any one of them is a megabuck sort of endeavor. You can predict that this or that will happen. That only gets you just so far. There are a lot of fine details that you can only find out by experiment. The graph at the bottom of this URL http://www.4timing.com/techcrystal.htm shows that there are actually 3 turn over temperatures. The Beckman graph at the bottom of that page shows a number of curves that have no turnover (those below 0 angle) . For the ones that do have a turnover, each one has an upper turn and a lower turn. The magic point in the middle that they all go through is generally called the inflection temperature. Lots of make your head hurt info at: http://www.ieee-uffc.org/frequency-control/learning/fc_conqtz2.html I don’t see anything on a quick Google search that actually give the Beckman constants. Do AT crystals used in ovens take advantage of the UTP? Yes. On a precision AT based oven, the oven temperature is matched to the turn over of the crystal by a process known as “turn hunting”. Once this is done the unit is run over temperature and the offset from this point is adjusted to optimize the temperature performance. In a modern approach, the oven gain is also optimized for best temperature performance during the same set of temperature runs. -- So we are just lucky that an AT cut works well at a convenient temperature and that an SC cut works well with an oven. A life form on some other star might not be so lucky. The AT is far from luck. A *lot* of people spent a few decades running experiments to come up with what we call the AT. I often wonder if we have run out of two letter combinations for naming cuts and soon will have to go to three letter combos. Likewise the SC was not so much a search for temperature performance as for stress compensation in a single plane. An enormous amount of effort went into both the theoretical and the experimental sides of that discovery. In both cases, the parts we have are as much a function of equipment as anything else. The SC required double axis cutting and x-ray gear to be perfected. Earlier, the AT and it’s many cousins required the whole single axis X-ray and cutting prices to be worked out. That doesn’t even get into mounting structures or enclosures … Bob -- These are my opinions. I hate spam. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] looking for SMT oscillator SC cut, with no oven
For a project at work, I'm looking for a good close in phase noise oscillator (better than -100dBc@ 10Hz, -120dBc would be nice) at 100 MHz in a SMT form factor. But it doesn't need good temperature stability. There's tons of SMT OCXOs out there with reasonably good performance, but they draw watts. My application is actually quite temperature stable already AND I have an external reference to measure against. Most of the lower powered oscillator modules are TCXO, and have, maybe, -80dBc at 10MHz. I guess we could go to a discrete design with a crystal and amplifier, but a little clock module would be a simpler solution. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/26/15 1:28 PM, steve heidmann via time-nuts wrote: Rakon has always impressed me . I'll take a look. The online datasheets don't have phase noise data for close in frequencies (at least the 3 I looked at).. some give a integrated jitter but it's for 12kHz and out, and I've noticed there's lots of ultra low noise, low jitter oscillators out there that have very good noise performance from a few kHz out, but are pretty bad at 10 and 100 Hz. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Am 26.08.2015 um 22:04 schrieb Javier Herrero: I suppose that one of the alternatives that you've explored are the ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf looks just like this one from Crystek: http://www.digikey.de/product-search/de?keywords=cvhd-950 but that fails the specs, also. If you have a good quality 5 or 10 MHz source in your system, you can lock the VCXO to it and clean it up close to the carrier. Last week, I asked for the prices of the 100 MHz Pascalls (not SMD but SMA) but at € 4K +VAT a piece I better make someone select crystals myself. :-( Maybe Axtal has something. They say that they are 3rd overtone, but it seems more an AT-cut than a SC, and anyway is around 10dB poorer SC requires high temperature, that does not go together well with SMD and low power. regards, Gerhard ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Hello, Jim, I suppose that one of the alternatives that you've explored are the ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf They say that they are 3rd overtone, but it seems more an AT-cut than a SC, and anyway is around 10dB poorer than your requirements. An I suppose that to make surgery in an AOCJY (that fully meets your requirement) to remove the oven will not be adequate :) Also it is a bit bulky... Regards, Javier On 26/08/2015 20:23, Jim Lux wrote: For a project at work, I'm looking for a good close in phase noise oscillator (better than -100dBc@ 10Hz, -120dBc would be nice) at 100 MHz in a SMT form factor. But it doesn't need good temperature stability. There's tons of SMT OCXOs out there with reasonably good performance, but they draw watts. My application is actually quite temperature stable already AND I have an external reference to measure against. Most of the lower powered oscillator modules are TCXO, and have, maybe, -80dBc at 10MHz. I guess we could go to a discrete design with a crystal and amplifier, but a little clock module would be a simpler solution. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
Rakon has always impressed me . From: Jim Lux jim...@earthlink.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, August 26, 2015 11:23 AM Subject: [time-nuts] looking for SMT oscillator SC cut, with no oven For a project at work, I'm looking for a good close in phase noise oscillator (better than -100dBc@ 10Hz, -120dBc would be nice) at 100 MHz in a SMT form factor. But it doesn't need good temperature stability. There's tons of SMT OCXOs out there with reasonably good performance, but they draw watts. My application is actually quite temperature stable already AND I have an external reference to measure against. Most of the lower powered oscillator modules are TCXO, and have, maybe, -80dBc at 10MHz. I guess we could go to a discrete design with a crystal and amplifier, but a little clock module would be a simpler solution. ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/26/15 2:38 PM, Gerhard Hoffmann wrote: Am 26.08.2015 um 22:04 schrieb Javier Herrero: I suppose that one of the alternatives that you've explored are the ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf looks just like this one from Crystek: http://www.digikey.de/product-search/de?keywords=cvhd-950 Yep, that's one (and similar ones) that's my current best I found in an hour of googling but that fails the specs, also. If you have a good quality 5 or 10 MHz source in your system, you can lock the VCXO to it and clean it up close to the carrier. Nope.. this oscillator is the ADC clock: it's a direct sampling receiver to look at narrow band signals in the 3-30 MHz range. Maybe Axtal has something. I'll look.. They say that they are 3rd overtone, but it seems more an AT-cut than a SC, and anyway is around 10dB poorer SC requires high temperature, that does not go together well with SMD and low power. SC only requires high temperature if you want to operate close to the turnover to minimize temperature effects. I've got a GPS 1pps to count my oscillator, so the sampled data can be post processed to take out the frequency variations. You'd get a bunch of digital samples and the timestamps when the 1pps occurs. I'm kind of hoping someone has run across a SMT OCXO where there's a separate oscillator and oven power pin. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
But if he needs 100dBc at 10Hz that is Wenzel's stronghold [https://twitter.com/ultralownoise] look that: http://www.wenzel.com/wp-content/parts/501-04517.pdf 73 KJ6UHN Alex On 8/26/2015 2:38 PM, Gerhard Hoffmann wrote: Am 26.08.2015 um 22:04 schrieb Javier Herrero: I suppose that one of the alternatives that you've explored are the ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf looks just like this one from Crystek: http://www.digikey.de/product-search/de?keywords=cvhd-950 but that fails the specs, also. If you have a good quality 5 or 10 MHz source in your system, you can lock the VCXO to it and clean it up close to the carrier. Last week, I asked for the prices of the 100 MHz Pascalls (not SMD but SMA) but at € 4K +VAT a piece I better make someone select crystals myself. :-( Maybe Axtal has something. They say that they are 3rd overtone, but it seems more an AT-cut than a SC, and anyway is around 10dB poorer SC requires high temperature, that does not go together well with SMD and low power. regards, Gerhard ___ 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/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
dk...@arcor.de said: SC requires high temperature, that does not go together well with SMD and low power. Is there anything fundamental about SC that forces the turn over temperature to be high? Or is is something like SC is only used in ovens and they have to be higher than ambient so nobody ever makes one at the magic angle that would give a lower turn over temp. -- These are my opinions. I hate spam. ___ 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.
Re: [time-nuts] looking for SMT oscillator SC cut, with no oven
On 8/26/15 1:04 PM, Javier Herrero wrote: Hello, Jim, I suppose that one of the alternatives that you've explored are the ABLNO from Abracon http://www.abracon.com/Precisiontiming/ABLNO.pdf They say that they are 3rd overtone, but it seems more an AT-cut than a SC, and anyway is around 10dB poorer than your requirements. An I suppose that to make surgery in an AOCJY (that fully meets your requirement) to remove the oven will not be adequate :) Also it is a bit bulky... exactly.. I've thought about delidding a OCXO and cutting the trace. That's a fairly expensive operation, maybe? (by the time we find a tech to do it, write the procedure, etc.) It would turn a $50 oscillator into a several thousand dollar oscillator. Still cheaper than designing a new oscillator from scratch. Or if someone knows of an OCXO where the oven power is separate from the oscillator power, that would make it easy. Darn these highly integrated parts..grin ___ 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.
