[time-nuts] A better Lady Heather 4.0 download page

John Miles is now hosting the latest Lady Heather 4.0 files. His server is a little less skeezy than tinyupload.com (which on Windows machines apparently offers to update your Java with about every click). I've used tinyupload for years on a Mac, and never got such a "generous" offer. No

[time-nuts] OT: A paper on Cs + Zeeman etc.

Even though nothing to do with time, I found the paper CESIUM OPTICALLY PUMPED MAGNETOMETERS http://www.gserentals.co.uk/gse/pdf/Theory%20Cesium%20Optically%20Pumped%20Magnetometers.pdf to be an interesting read. I can only imagine what HP and Varian engineers went through -pete

Re: [time-nuts] SE880 GPSDO

On Wednesday, April 27, 2016 09:40:05 PM Attila Kinali wrote: > On Wed, 27 Apr 2016 20:18:10 +0200 > > Mike Cook wrote: > > > Use this CW signal on all the telescope stations to phase lock a local > > > OCXO. Using a good OCXO, it should be possible to use loop bandwidths >

Re: [time-nuts] SE880 GPSDO

On Wed, 27 Apr 2016 20:18:10 +0200 Mike Cook wrote: > > Use this CW signal on all the telescope stations to phase lock a local > > OCXO. Using a good OCXO, it should be possible to use loop bandwidths > > in the 0.1-10Hz range. My guess is, that this frequency transfer

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

Lars, On 04/27/2016 02:14 PM, Lars Walenius wrote: Thanks Magnus and Charles, Could you please explain a little more about this: Charles wrote: Loop filters in commercial GPSDOs use algorithms that suppress systematic ripple on the VCO control related to the comparison frequency. Magnus

Re: [time-nuts] SE880 GPSDO

> > Assuming that you have an amateur radio license, you could use a > well located central station to transmit a CW signal in the 70cm or > 23cm band. There should be some effort put into this station > to make it stable (eg by using a good rubidium as frequency source, > or even an ensemble)

[time-nuts] Dead tree material: Ships, Clocks, and Stars: The Quest for

Greetings Time Nuts, I read the message below and made a trip to my closest OLLIE's store in Harrisonburg, VA. I found the book with the assistance of the book area manager and purchased it. They now have 5 left in Harrisonburg. If you are interested in the book and have an OLLIE'S nearby it

Re: [time-nuts] SE880 GPSDO

On Wed, Apr 27, 2016 at 7:21 PM, Bruce Griffiths wrote: > Stabilising the GPS receiver antenna temperature is probably a good idea > particularly if it has bandpass filter(s). It's not so clear that temperature stabilization of the antenna is necessary. There have

Re: [time-nuts] More graphs: OCXO step, holdover recovery

Lars wrote: >> What puzzles me is the large hump upwards in DACvalue. Anyone knows what is >> the reason? Hal wrote: >My guess is poor filtering on the initial data when coming out of holdover, >probably complicated by inadequate testing and/or that case not being >important. > >I'm pretty sure

Re: [time-nuts] Lady Heather Ver 4.0 beta test available (has Linux support)

I've updated my existing LH download page with Mark's new beta version in both .zip and (Windows) setup.exe formats: http://www.ke5fx.com/heather/readme.htm There's also a link to his readme.txt file with Linux build instructions. (Mark is the best point of contact for anyone with questions on

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

Thanks Magnus and Charles, Could you please explain a little more about this: Charles wrote: >> Loop filters in commercial GPSDOs use algorithms that suppress >> systematic ripple on the VCO control related to the comparison frequency. Magnus wrote: >It will be there, so you need to manage it

Re: [time-nuts] SE880 GPSDO

Stabilising the GPS receiver antenna temperature is probably a good idea particularly if it has bandpass filter(s). Bruce On Wednesday, 27 April 2016 9:01 PM, Attila Kinali wrote: On Wed, 27 Apr 2016 01:30:49 +0200 Ilia Platone wrote: > I will

Re: [time-nuts] SE880 GPSDO

It was a joke :) Interesting the idea of Attila, it can be the less expensive solution: "Assuming that you have an amateur radio license, you could use a well located central station to transmit a CW signal in the 70cm or 23cm band. There should be some effort put into this station to make it

Re: [time-nuts] SE880 GPSDO

On Wed, Apr 27, 2016 at 7:51 AM, Attila Kinali wrote: > > > > Another way would be to use L1/L2 receivers with calibrated antennas. > I know that BIPM has a GPS station that can deliver time transfer > accuracy <2ns over a distance of several 100km. It could be possible > to use

Re: [time-nuts] SE880 GPSDO

A 60kHz receiver is unlikely to be useful for nanosecond timing applications. Bruce On Wednesday, 27 April 2016 6:36 PM, Ilia Platone wrote: Hi All, I read from an article about this receiver: C-Max CMMR-6P-60 Can it be useful? One of the places where I'll

Re: [time-nuts] SE880 GPSDO

On Wed, 27 Apr 2016 01:30:49 +0200 Ilia Platone wrote: > I will use a dedicated FPGA design, and the data will be stored into an > SDXC card (UHS), or an IDE drive (maybe not), in RAW mode (no filesystem). Please be aware that SDCards performance spec is peak and best

Re: [time-nuts] SE880 GPSDO

Hi All, I read from an article about this receiver: C-Max CMMR-6P-60 Can it be useful? One of the places where I'll setup the telescopes will be in mount Carpegna, near where I live. There are the repetitors of television and radio over there. Can the carrier wave of such repetitors be used

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

On 04/27/2016 01:12 AM, Charles Steinmetz wrote: Lars wrote: I have wondered what is meant by a proper digital filter below? Is a proper digital filter something more than the LP-filter + PI-loop I use in the DIY Arduino GPSDO? What is used in commercial GPSDOs? The loops are