GPSDO source in Europe? - Page 1
Forum section: electronics / general

author: daloev
author_rank: Contributor
timestamp: March 02, 2023, 02:54:53 am
content: A product at my workplace uses a GPSDO as a timing source for White Rabbit equipment. We are expanding it to Germany, and I am looking for a good GPSDO we can use. We have used a Trimble Thunderbolt E so far at the US installations, but it is difficult to find another. Trimble says they are working on an updated multi-GNSS Thunderbolt, and apparently the company is just letting the stock of Thunderbolt Es run out, and we haven't found any.I was wondering if people in this forum could point me to good GPSDO sources in Europe? We need a reliable commercial product, and if we can purchase from a European, or even German source, it is likely to save us shipping and import cost and time.

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: March 02, 2023, 03:43:32 am
content: Furuno (Japan) GPS products are available in Europe. You could look at its product range, as a starting point.

author: Detlev
author_rank: Regular Contributor
timestamp: March 02, 2023, 06:58:29 am
content: ask Meinberg. they mainly produce time systems. They have been on the market for a long time (I bought my first PCM radio remote control for model aircraft there 40 years ago).https://www.meinberg.de/

author: doktor pyta
author_rank: Frequent Contributor
timestamp: March 02, 2023, 09:42:31 am
content: https://dxpatrol.pt/produto/gpsdo/they are from Portugal

author: jonpaul
author_rank: Super Contributor
timestamp: March 02, 2023, 10:03:27 am
content: Leo Bodnar GPS DSO UK£ 110..165http://www.leobodnar.com/shop/index.php?main_page=index&cPath=107excellent units highly recommendedj

author: daloev
author_rank: Contributor
timestamp: March 02, 2023, 09:17:02 pm
content: Thanks for the pointers. Just today I received a (previously ordered) Leo Bodnar unit to try.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 03, 2023, 04:30:49 pm
content: Hard to beat LeoI put together a GSPDO from junk parts and still had over $50 bucks of parts that I had to buy.....Leo gets my vote.

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2023, 11:56:23 pm
content: You could look at Septentrio (located in Belgium); these guys seem to make the more serious stuff.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: March 04, 2023, 11:01:37 pm
content: I'm a (very satisfied) user of Leo Bodnar Mini GPS Clock for over a year. There is one particular feature of this unit that you might need to take into account. The Mini GPS Clock uses a TCXO as the controlled clock, plus the unit gets quite warm to touch. As a result, a sudden change in the case temperature (if you hold the unit in your hand, for example) would result in a frequency deviation. On the graph below is the result for my own unit, held by hand for ~2min (till the frequency came back to 10MHz) and then released. As you may see, the frequency change is about -1ppb (Mini GPS Clock is used as a reference for HP5386A, measuring the OCXO frequency, so a positive change reflects a lower frequency from Mini).CheersAlex

author: bingo600
author_rank: Super Contributor
timestamp: March 05, 2023, 08:55:16 pm
content: Not Europe, but US.Jackson Lab is worth looking at, for a Tbolt replacementhttps://www.jackson-labs.com/index.php/products/Bingo

author: daloev
author_rank: Contributor
timestamp: March 08, 2023, 03:56:16 pm
content: I had not read about the temperature sensitivity of the Leo Bodnar. I am very glad to know that because it means it wouldn't work for our purpose. I need the stability over a long period of time in spite of minor temperature variations. It will be in a data center so the temperature will be quite stable, but we wouldn't want, for example, someone working on other equipment in the rack to cause a deviation.

author: J-R
author_rank: Super Contributor
timestamp: March 08, 2023, 08:06:59 pm
content: Concerned about stability but also want to be holding stuff in your hands? In the Metrology thread? Yikes...The Leo units are tiny, I would find a 1U rack mount enclosure and put it inside to keep paws and breezes away from it.

author: mendip_discovery
author_rank: Super Contributor
timestamp: March 08, 2023, 08:17:40 pm
content: Quote from: daloev on March 08, 2023, 03:56:16 pmThat temp rise (~10°C) caused a 1 ppb change, do you how small of a movement that is? How well behaved are your other units? Just looking at uncertainty from another lab 2.1ppb, I would say it's not unexpected for any unit to drift with temp changes.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: March 09, 2023, 01:07:04 am
content: Yes, only a fast temperature change creates a variation, if the case is protected from air movements and hands, as J-R suggested, it should not be a problem. Slow temperature changes (more than 1min per degree) should be fully compensated by the control loop.CheersAlex

author: nctnico
author_rank: Super Contributor
timestamp: March 09, 2023, 11:42:26 am
content: Quote from: daloev on March 08, 2023, 03:56:16 pmI hope you realise that you'll need something like a Rb clock tied to the GPS receiver to get any form of long term stability? The typical, OCXO based GPSDOs will wander around +/-50ns over the period of 24 hours. The Trimble unit you mentioned earlier is no exception. A Rubidium clock (+ cleanup oscillator to get rid of the short term drift / phase noise of a Rb clock) can offer better performance. If you need even better stability, then Cesium is the way to go.