Re: [time-nuts] WTB: GPSDO

Hi > On Mar 14, 2017, at 6:33 PM, Tim Lister wrote: > > On Fri, Mar 10, 2017 at 2:35 PM, Chris Albertson > wrote: >> A GPSDO is not hard to make. All you need is some way to compare the >> phase of two signals, an XOR gate can do that. Then a

Re: [time-nuts] Bye-Bye Crystals

In my design I need 10ppM, and then I divide by 8. Software can't correct for anything. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Bownes Sent: Tuesday, March 14, 2017 10:50 AM To: Discussion of precise time and frequency measurement Subject:

Re: [time-nuts] Bye-Bye Crystals

On 3/14/17 3:49 PM, Magnus Danielson wrote: There is a number of more or less odd-ball frequences that occur. For instance, 25 MHz isn't used as much as 125 MHz these days for Ethernet, as it matches the needs of GE. 148,5 MHz is another, in that range there is a number of numbers that fit

Re: [time-nuts] Bye-Bye Crystals

Rick Yes, the 10811A is a good example of the sort of kludge that is required when one tries to adapt the Colpitts XO to work with an overtone crystal. However, apart from that, the design is still a lot better than those in most of the ham publications (eg. clamp diodes on JFET gates to limit

Re: [time-nuts] Bye-Bye Crystals

On 3/14/17 3:17 PM, Magnus Danielson wrote: So well yes, you learn the hard way what those 4-leggers do when you have a bit of requirements. Later I dug up the patent for the process, which was focused more on the production of one standard product and late setting the frequency for customer

Re: [time-nuts] Bye-Bye Crystals

Attila, On 03/14/2017 08:39 PM, Attila Kinali wrote: On Tue, 14 Mar 2017 13:39:02 +0100 Magnus Danielson wrote: Some claims that MEMS will kill crystals. It will surely eat a good market share, but I think there is applications where MEMS is not mature enough

Re: [time-nuts] WTB: GPSDO

On Fri, Mar 10, 2017 at 2:35 PM, Chris Albertson wrote: > A GPSDO is not hard to make. All you need is some way to compare the > phase of two signals, an XOR gate can do that. Then a small $2 > process moves the control voltage on the crystal.I tried one to >

Re: [time-nuts] Bye-Bye Crystals

Hi, Oh yes. I remember a certain design from a certain vendor. It was an crystal oscillator, sort of. Available in many diverse frequencies (hint). It was really a crystal oscillator and a PLL that could be programmed relatively inexpensively. Solves many problems, so it's a fine product,

Re: [time-nuts] Bye-Bye Crystals

On 3/14/17 12:39 PM, Attila Kinali wrote: On Tue, 14 Mar 2017 13:39:02 +0100 Magnus Danielson wrote: Some claims that MEMS will kill crystals. It will surely eat a good market share, but I think there is applications where MEMS is not mature enough compared to

Re: [time-nuts] Bye-Bye Crystals

For other common crystal frequencies, let's not forget 3.579545 MHz and 4x that - NTSC TV color burst and others listed here... https://en.wikipedia.org/wiki/Crystal_oscillator_frequencies On Tue, Mar 14, 2017 at 3:39 PM, Attila Kinali wrote: > On Tue, 14 Mar 2017 13:39:02

Re: [time-nuts] Bye-Bye Crystals

On Tue, 14 Mar 2017 13:39:02 +0100 Magnus Danielson wrote: > Some claims that MEMS will kill crystals. It will surely eat a good > market share, but I think there is applications where MEMS is not mature > enough compared to crystals. MEMS is quite mature, it's

Re: [time-nuts] Bye-Bye Crystals

Not only that. Good luck finding a datasheet with *any* analog specifications for its internal oscillator. Here are the pins for an external crystal. The microchip PICs are nice, they give you the goldilocks selection for drive level a little cool, a little hot, maybe just right. On Tue, Mar 14,

Re: [time-nuts] Bye-Bye Crystals

On 3/14/2017 4:03 AM, Bruce Griffiths wrote: Looking at oscillator circuits like the HP10811A will give some idea of some of the additional complexity required for a overtone operation. Dissecting a few ocxos may also be helpful. Some start with a 10MHz crystal and a Colpitts sustaining

Re: [time-nuts] Bye-Bye Crystals

Hi Some (but not all) of the resonant structures in the MEMS parts are effectively multi resonator / multi peak structures. Because of this the phase noise has multiple major bumps in it as you get into the region of all the peaks. Thats not going to give you great close in phase noise or

Re: [time-nuts] Bye-Bye Crystals

not to mention +/- a few hundred ppm is not a big deal. You can always correct for it in software. ;) On Tue, Mar 14, 2017 at 8:49 AM, jimlux wrote: > On 3/14/17 5:04 AM, Bob Camp wrote: > >> Hi >> >> The cost difference between a complete oscillator package and a simple

Re: [time-nuts] Bye-Bye Crystals

Hi > On Mar 14, 2017, at 8:49 AM, jimlux wrote: > > On 3/14/17 5:04 AM, Bob Camp wrote: >> Hi >> >>> The cost difference between a complete oscillator package and a simple >>> crystal is tiny. The osc is often cheaper if you include board space or >>> engineering time.

Re: [time-nuts] Bye-Bye Crystals

On 3/14/17 5:04 AM, Bob Camp wrote: Hi The cost difference between a complete oscillator package and a simple crystal is tiny. The osc is often cheaper if you include board space or engineering time. Purchased in volume, the difference it the price of a crystal vs a complete XO is enormous.

Re: [time-nuts] Bye-Bye Crystals

Hi, Some claims that MEMS will kill crystals. It will surely eat a good market share, but I think there is applications where MEMS is not mature enough compared to crystals. Another aspect is that various forms of synthesis technologies now exists, so that a high frequency CMOS oscillator

Re: [time-nuts] Bye-Bye Crystals

On 3/14/17 12:19 AM, Chris Albertson wrote: I think what he means is that the typical device sold today has four terminals not two. It looks like a crystal because it is inside a little silver can but has four lead wires Power, ground and "output" and the fourth lead might not be used. It is

Re: [time-nuts] Bye-Bye Crystals

Hi > On Mar 14, 2017, at 3:19 AM, Chris Albertson > wrote: > > I think what he means is that the typical device sold today has four > terminals not two. It looks like a crystal because it is inside a > little silver can but has four lead wires Power, ground and

Re: [time-nuts] Bye-Bye Crystals

Hi > On Mar 14, 2017, at 4:44 AM, Hal Murray wrote: > > > artgod...@gmail.com said: >> I'm not after quality - I do have an application in mind but it doesn't need >> to compete with mass production. Just wondering if it's feasible to make >> something crude that will

Re: [time-nuts] Bye-Bye Crystals

For a sinewave oscillator http://www.wenzel.com/wp-content/uploads/xtalosc.pdf is a start for fundamental crystals. However the npn transistor operates a little too close to saturation for my liking. A small change to the biasing of the npn will fix this. With overtone crystal operation mode

Re: [time-nuts] Bye-Bye Crystals

For interest, and as part of art project involving crystals. I want to show a less third-age usage than is common in that space :).Acceleration effect on frequency may also be featured. No way would I do it for cost or quality. Like you, I normally use packaged oscillators for most things -

Re: [time-nuts] Bye-Bye Crystals

I think what he means is that the typical device sold today has four terminals not two. It looks like a crystal because it is inside a little silver can but has four lead wires Power, ground and "output" and the fourth lead might not be used. It is an "XO" not an "X". But I argue that every one

Re: [time-nuts] Bye-Bye Crystals

artgod...@gmail.com said: > I'm not after quality - I do have an application in mind but it doesn't need > to compete with mass production. Just wondering if it's feasible to make > something crude that will resonate. Are you doing this for fun or ??? Feasible? Sure. Cheaper? That depends.

Re: [time-nuts] Bye-Bye Crystals

https://www.youtube.com/watch?v=b--FKHCFjOM On Mon, Mar 13, 2017 at 8:11 PM, Hal Murray wrote: > > jim...@earthlink.net said: > > what about cheap crystals for microcontrollers.. I think the Arduino, > for > > instance, uses a crystal (and the oscillator electronics are