Re: [time-nuts] GPS Timing Source -- looking at buying
Keep in mind, SMPTE/EBU is timecode, AES/EBU is digital audio. 3 orders of magnitude difference in the bit rates. Chris was talking timecode. Ed -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Friday, July 09, 2010 8:38 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS Timing Source -- looking at buying Hi The Thunderbolt has a GPS and an OCXO inside it. It's built in smarts align a PPS created from the OCXO to the GPS PPS. This allows the PPS to be more stable than a normal GPS PPS (less jitter). It also provides holdover on the PPS if and when GPS sat's are not available. Since your ultimate objective is (I think) AES / EBU timing, jitter is an important consideration. Bob On Jul 9, 2010, at 3:10 AM, Chris H wrote: I might go for the Garmin one to start with, and see how it all works.. and then move up to a more reliable source of timing source in the future... When you say Reliable, what exactly do you all mean--- does it loose time? Does it loose lock to the satellites? because it's only millisecond accurate, is that your concerns Please correct me if I am wrong: If it's pulsing every second, and that second is generated by the lock to the satellite, then should it not be as accurate as the device that it's getting it's lock from? (Sorry I am new to all this) On Fri, 2010-07-09 at 19:02 +1200, Chris H wrote: Yes sorry -- stratum 1 -- brain fart :( On Fri, 2010-07-09 at 06:32 +, Paul Nicholson wrote: Chris H wrote: Would be good as a timing source for GPS ... make a PC into a Stratum 0 timing device? I think it would count as stratum 1, since you are 1 hop away from a master time source. This page may be of interest, http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm Trimble Thunderbolts have been recommended on this list as a proper timing grade GPS, superior to these EOM Garmin GPS units. There's a reliable source of Thunderbolts on E-bay. I currently have one of these on order, http://cgi.ebay.co.uk/290322053618 -- Paul Nicholson -- ___ 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 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 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] Rubidium oscillator controlled clock
Dear list members - a couple of weeks ago I found the time-nuts mailing list and had a wonderful time reading through old posts as well as having a look at the web pages of some of its participants. This triggered a long desire of mine to have some kind of a homebrew atomic clock - not necessarily based on a cesium primary standard, but maybe something built around a cheaper rubidium oscillator. Since I was lucky to find an EFRATOM LPRO-101 for a quite reasonable price, I decided to build my own frequency standard and clock around this. I am sure this does not (yet? :-) ) qualify me as a time nut, but maybe you will like my contraption which is described at http://www.vaxman.de/projects/rb_clock/ Best regards - sincerely, Bernd. :-) ___ 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] Rubidium oscillator controlled clock
Very Nice, but way too neat, tell me you cleaned up for the pictures. Stanley - Original Message From: ulm...@vaxman.de ulm...@vaxman.de To: TIME-NUTS@febo.com Sent: Sun, July 11, 2010 2:40:01 PM Subject: [time-nuts] Rubidium oscillator controlled clock Dear list members - a couple of weeks ago I found the time-nuts mailing list and had a wonderful time reading through old posts as well as having a look at the web pages of some of its participants. This triggered a long desire of mine to have some kind of a homebrew atomic clock - not necessarily based on a cesium primary standard, but maybe something built around a cheaper rubidium oscillator. Since I was lucky to find an EFRATOM LPRO-101 for a quite reasonable price, I decided to build my own frequency standard and clock around this. I am sure this does not (yet? :-) ) qualify me as a time nut, but maybe you will like my contraption which is described at http://www.vaxman.de/projects/rb_clock/ Best regards - sincerely, Bernd. :-) ___ 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] Rubidium oscillator controlled clock
Bernd, Stanley, On 07/11/2010 10:27 PM, Stanley Reynolds wrote: Very Nice, but way too neat, tell me you cleaned up for the pictures. I agree. Very nice, but my lab bench is full of junk, more junk and essentially a lot of junk all over the place. The remaining issue on that rubidium is if there is any plans to bring it into GPS control? Just logging the PPS against a PPS from a GPS regularly would suffice to get some aid in trimming the rubidium up. Cheers, Magnus Stanley - Original Message From: ulm...@vaxman.deulm...@vaxman.de To: TIME-NUTS@febo.com Sent: Sun, July 11, 2010 2:40:01 PM Subject: [time-nuts] Rubidium oscillator controlled clock Dear list members - a couple of weeks ago I found the time-nuts mailing list and had a wonderful time reading through old posts as well as having a look at the web pages of some of its participants. This triggered a long desire of mine to have some kind of a homebrew atomic clock - not necessarily based on a cesium primary standard, but maybe something built around a cheaper rubidium oscillator. Since I was lucky to find an EFRATOM LPRO-101 for a quite reasonable price, I decided to build my own frequency standard and clock around this. I am sure this does not (yet? :-) ) qualify me as a time nut, but maybe you will like my contraption which is described at http://www.vaxman.de/projects/rb_clock/ Best regards - sincerely, Bernd. :-) ___ 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 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] Loran-C Anthorn
Greetings to the group. I would like to have the exact (and trustworthy...) WGS84 coordinates of the Anthorn Loran-C antenna. Searching the net I got at least three different sets of LAT/LONG. It seems to me that exactitude is not a cult anymore, except for us the nutties... I would also appreciate to have the exact Coding Delay for that transmitter. (Not the Emission Delay, which is known to be 27,300.00 uS). Thanks in advance. Antonio CT1TE ___ 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] Rubidium oscillator controlled clock
Well done. Nice wiring and a comfortable shack to work in. On Sun, Jul 11, 2010 at 4:51 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Bernd, Stanley, On 07/11/2010 10:27 PM, Stanley Reynolds wrote: Very Nice, but way too neat, tell me you cleaned up for the pictures. I agree. Very nice, but my lab bench is full of junk, more junk and essentially a lot of junk all over the place. The remaining issue on that rubidium is if there is any plans to bring it into GPS control? Just logging the PPS against a PPS from a GPS regularly would suffice to get some aid in trimming the rubidium up. Cheers, Magnus Stanley - Original Message From: ulm...@vaxman.deulm...@vaxman.de To: TIME-NUTS@febo.com Sent: Sun, July 11, 2010 2:40:01 PM Subject: [time-nuts] Rubidium oscillator controlled clock Dear list members - a couple of weeks ago I found the time-nuts mailing list and had a wonderful time reading through old posts as well as having a look at the web pages of some of its participants. This triggered a long desire of mine to have some kind of a homebrew atomic clock - not necessarily based on a cesium primary standard, but maybe something built around a cheaper rubidium oscillator. Since I was lucky to find an EFRATOM LPRO-101 for a quite reasonable price, I decided to build my own frequency standard and clock around this. I am sure this does not (yet? :-) ) qualify me as a time nut, but maybe you will like my contraption which is described at http://www.vaxman.de/projects/rb_clock/ Best regards - sincerely, Bernd. :-) ___ 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 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] High Voltage lead on HP Cesium Tubes
Has anyone ever replaced a high voltage lead on an HP Cesium tube? I have a 5061A that required prolonged pumping at +6000 VDC to get the Ion Pump current to go down enough to allow the unit to turn on the CS Oven but then would slowly increase to the point that it would again not let the CS Oven turn on. At +6000 VDC, the current would be about 1400 uA but only about 30 uA at +4000 VDC. It got me to thinking that there was some sort of HV breakdown going on. On inspecting the tube and HV lead more carefully, I found the +3500 VDC lead cracked and considerable 'soot' on the silicone 'cap' on the tube where the red HV lead entered the tube. I removed the connector, cleaned the wire and silicone cap, separated the silicone from the lead and slid some heat shrink tubing over the wire and into the silicone cap. I used the heat gun to shrink it in place then placed another layer on this. Now, the tube seems to work OK (at least observing it for about 48 hours) with the Ion Pump I stable at about 6 and with no increase, a distinct change and improvement from before. Perhaps I should be satisfied with what I have got but I was wondering what is under the silicone caps and how to go about removing them to replace the +3500 VDC and -2500 VDC leads. Does anyone have any experience with this? Thanks in advance. Joe ___ 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.
