Re: [time-nuts] Advise on building a DIY GPSDO?

zl1...@gmx.com said: > One other point. Attila mentioned using "LEA-M8T". I assume the T suffix > relates to Time rather than the plain GPS. What is the difference? Apart > from 50% higher cost. If you use GPS for navigation, you need 4 satellites to get 4 equations that you can solve for X,

Re: [time-nuts] Advise on building a DIY GPSDO?

It can easily be done using a variant of the dual conjugate regenerative divider.Feed the 24 MHz signal into the LO port of a mixer.Use a dual bandpass filters centred on 14MHz and 10MHz to filter the IF port amplify the outputs of the bandpass filters and drive the mixer RF port with  the

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi To filter out the close in noise on the output of the GPS module (regardless of output frequency) you need a very narrow bandwidth loop. Cross over points in the 0.01 Hz to < 0.001 Hz range are not at all unusual for these loops. Starting off at a high(er) frequency does not help in this

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi all, I'm fairly new here and might not fully understand things. Earlier in this thread it was suggested that one lock an 8Mhz signal to a 10 Mhz signal by analogue methods. To quote A Plummer: "and it is relative easy to make 10MHz from 8MHz with analog frequency manipulation, which

Re: [time-nuts] Building a mains frequency monitor

On 4/8/2016 7:19 PM, Nick Sayer via time-nuts wrote: The instructable I wrote about it is at http://www.instructables.com/id/Science-fair-How-accurate-is-the-AC-line-frequency/ There’s code for the Arduino and the Linux side as well as schematics. Hi Nick, Awesome, thanks mucho!!! thanks

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi Averaged over a long enough time (and without any hanging bridges) the frequency accuracy will be fine. The frequency accuracy of a 1 pps output on a GPS is “fine” on the same basis. Since 200 KHz is a “round division” off of any of the likely TCXO’s you will not have any jitter or spurs

Re: [time-nuts] Advise on building a DIY GPSDO?

I do not know what U blox does but I know when we use 200 KHz out of the 1 pps output on a $ 10 ublox 6 we consistently get better than 1 E-10 closer to 1 E-11 out of the Morion have the data Bert Kehren In a message dated 4/9/2016 10:01:05 A.M. Eastern Daylight Time, kb...@n1k.org

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi > On Apr 8, 2016, at 10:31 PM, Graham / KE9H wrote: > > The lowest jitter way to do this kind of conversion is to multiply the > signal up to some common multiple frequency, then divide it back down to > where you want to be. For instance, with 8 or 24 MHz, multiply

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi > On Apr 8, 2016, at 9:39 PM, time...@metachaos.net wrote: > > Hello Bob, > > Friday, April 8, 2016, 6:13:07 PM, you wrote: > >> Hi > >> If you start from a 24 MHz TCXO (different modules use different TCXO’s): > >> On an 8 MHz output, most of the time you divide by three. > >> On a 10

Re: [time-nuts] Advise on building a DIY GPSDO?

Hi > On Apr 8, 2016, at 10:35 PM, Herbert Poetzl wrote: > > On Fri, Apr 08, 2016 at 06:13:07PM -0400, Bob Camp wrote: >> Hi > >> If you start from a 24 MHz TCXO (different modules use >> different TCXO’s): > >> On an 8 MHz output, most of the time you divide by three. >

Re: [time-nuts] Advise on building a DIY GPSDO?

On Fri, 8 Apr 2016 21:31:31 -0500 "Graham / KE9H" wrote: > The lowest jitter way to do this kind of conversion is to multiply the > signal up to some common multiple frequency, then divide it back down to > where you want to be. For instance, with 8 or 24 MHz, multiply up

Re: [time-nuts] Advise on building a DIY GPSDO?

Am I missing something? KISS. If you start out with a 10 MHz OCXO use a tvb PIC to divide down to a lower frequency a 74HC74 to get symmetrical output of a $ 10 u-blox 6 and the PIC and 86 XOR. If no PIC capability ebay has LS90's for a one off. Bert Kehren In a message dated 4/9/2016

Re: [time-nuts] Advise on building a DIY GPSDO?

The lowest jitter way to do this kind of conversion is to multiply the signal up to some common multiple frequency, then divide it back down to where you want to be. For instance, with 8 or 24 MHz, multiply up to 240 MHz, then divide by 24 to get 10 MHz. Modern clock generator chips have this

Re: [time-nuts] Advise on building a DIY GPSDO?

Hello Bob, Friday, April 8, 2016, 6:13:07 PM, you wrote: > Hi > If you start from a 24 MHz TCXO (different modules use different TCXO’s): > On an 8 MHz output, most of the time you divide by three. > On a 10 MHz output, you need to divide by 2.4. The net result is that you > divide by 2

Re: [time-nuts] Advise on building a DIY GPSDO?

On Fri, Apr 08, 2016 at 06:13:07PM -0400, Bob Camp wrote: > Hi > If you start from a 24 MHz TCXO (different modules use > different TCXO’s): > On an 8 MHz output, most of the time you divide by three. > On a 10 MHz output, you need to divide by 2.4. > The net result is that you divide by 2

Re: [time-nuts] Advise on building a DIY GPSDO?

"Could you elaborate on this a little if time permits? I'm more a 'digital person' but it sounds interesting. Thanks in advance, Herbert " Yes Herbert here is; first divide 24MHz by two you get a very good quality absolute 50% duty cycle 12MHz, than you feed that 12MHx into mixer [which could