Re: [time-nuts] Datasheet for TeleQuarz 20TQG01?
Hi again, Replying to myself: More online searching has revealed that 20TQG01 is likely a date code (week 20 of year 2001, charge G?). The other identifiers printed on the OCXO are '7368' and 'EO10391410'. On 8/22/20 11:56 AM, Paul Boven wrote: Dear time nuts, In my surplus drawer, I found an OCXO which I would like to use for a home-built GPSDO. The part in question is a 10 MHz, 12V OCXO, type 20TQG01. It came from a flea market, and looks to have been removed from a PCB. It's fairly large metal case (h = 2.5cm, w = 4cm, l = 5cm) and has 7 pins. According to the seller, it achieves 1.2 ppb (!). Unfortunately, the Telequarz group no longer exists, and I've been unable to find anything resembling a datasheet. Any further information would be very welcome, especially pinout and performance parameters. Regards, Paul Boven. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Datasheet for TeleQuarz 20TQG01?
Dear time nuts, In my surplus drawer, I found an OCXO which I would like to use for a home-built GPSDO. The part in question is a 10 MHz, 12V OCXO, type 20TQG01. It came from a flea market, and looks to have been removed from a PCB. It's fairly large metal case (h = 2.5cm, w = 4cm, l = 5cm) and has 7 pins. According to the seller, it achieves 1.2 ppb (!). Unfortunately, the Telequarz group no longer exists, and I've been unable to find anything resembling a datasheet. Any further information would be very welcome, especially pinout and performance parameters. Regards, Paul Boven. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] another source of time...
Hi everyone, On 8/6/20 5:55 AM, jimlux wrote: On 8/5/20 4:18 PM, Mark Haun wrote: I wonder if someone maintains a directory of ionosondes. Seems like waste/duplication to have every interested party set up their own, instead of piggy-backing on what's already out there. There's also the pollution factor---one certainly hears them often enough while operating narrowband on shortwave, and while not particularly intrusive, we don't need more. yes, there is a directory of ionosondes.. I can't lay my fingers on it right now, but it's there. The WebSDR by Pieter-Tjerk de Boer (PA3FWM) samples all of of shortwave, and one of the experiments he's been doing is the tracking of ionosondes. http://websdr.ewi.utwente.nl:8901/chirps/ Regards, Paul Boven ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] White Rabbit
Hi Jim, On 7/16/20 1:37 PM, Jim Palfreyman wrote: Anyone here have experience with White Rabbit products? Any thoughts would be appreciated. Got to play with it extensively, using it to connect various radio telescopes together. There is a lively community around the White Rabbit project, and they have pushed it well beyond its original mission of controlling the LHC at CERN. Due to its open source nature, all kinds of tinkering is possible. We use special low-jitter White Rabbit hardware for frequency distribution. Using SFPs with (stabilized) lasers, the range and stability can be greatly increased. One of the things I've used it for is demonstrating VLBI fringes at 1.3 GHz, over 135 km of fiber, with optical (bi-directional) amplification along the route. It's roughly one order of magnitude worse in ADEV than a H-maser, up to about 1,000 seconds, where the curves cross over. https://pos.sissa.it/344/156/pdf Timing accuracy can be kept well under 1ns, even on long haul links (e.g. 185 km) with semi-desert climate and overhead fibre. The timing stability is much better than that. There are multiple vendors, and as the design is truly open, you could even build your own if you really wanted to. The project is still progressing, and work on a new generation of White Rabbit switches (with 10Gb/s) and end-points is well under way. Regards, Paul Boven. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Modern Rb atomic reference vs classic Cs
Hi Attila, list, On 3/17/20 9:51 PM, Attila Kinali wrote: At those prices, I'd rather go for a µQuans or SDS Rb clock. Those don't lose atoms like the Cs beam does and thus don't need a refill. Their lifetime is more likely in the decades than just a few years. Weakest link, as far as I know, are the lasers. And yes, after the second, at latest after the third Cs tube, these Rb devices are cheaper. And they are as much a primary standard as the 5071 is. We've actually looked into purchasing the muQuans Rb. We learned from the vendor that they need to be serviced and refilled every four years, which could possibly be stretched to five years. This entails sending your clock back to the manufacturer. Otherwise, it simply runs out of Rb. Given that we were going to deploy these in rather remote locations, we decided that the repeated shipping and down-time was just going to be too difficult to deal with. Regards, Paul Boven. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Cold Rubidium?
Hi Attila, everyone, On 11/3/19 7:12 PM, Attila Kinali wrote: You do not need to replenish the Rb supply, as the Rb atoms do not get used up. They are free floating in vaccuum and get captured by the MOT. Thus, unlike the Cs beam's oven, which just spits the Cs atoms out, the MOT does not need a storage for Rb atoms. Of course, some of the Rb will get lost due to wall absorption, but that should be only a minor fraction. I would also suspect that the laser system will fail before the clocks run out of Rb atoms. We were seriously considering the Muquans clock for a radio astronomy project. However, the company explained that the device has to be returned every 3 to 5 years for re-filling. Given the very remote location we were going to put these in, that was out of the question for us. Regards, Paul Boven. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
