The technology connections quip.... take your darn like. seriously tho, I cant wait for a video showing off two computers with the EXACT same time using that hardware standard

1:13 Okay, I just have to call this out. The "> 200,000x more accurate!" card here implying that a higher frequency makes it more accurate (or that these two frequencies even related to each other in a meaningful way) is **highly** misleading, straight up wrong even. Higher frequency does not mean better, not in the slightest. You can have a 1THz oscillator that is absolute garbage at keeping time. What matters for an oscillator is it's tolerance, stability, and phase noise. In this case since the oscillator is GPS-steered, tolerance matters slightly less, but stability and phase noise are still critical, and this is what something like a rubidium oscillator excels at, but it has nothing to do with how high a frequency it is, it has to do with how stable that frequency is, how little it shifts due to both environmental conditions and random fluctuations. Now, there are technical reasons related to phase-locked loops (which is used to get a different frequency out) why an underlying frequency standard should be reasonably high frequency, but that's not what sets quartz and rubidium oscillators apart from eachother, you can get quartz crystals tuned for the GHz region. What sets it apart is that a rubidium oscillator depends on atomic scale properties of electron energy levels in individual rubidium atoms which are relatively fundamental and unchanging, rather than depending on the relatively 'macroscopic' properties of a chunk of quartz crystal as a whole which depend on physical dimensions and environmental conditions.

You compile the Linux kernel so often it would be interesting for a video of how to do it. Just a suggestion.

love when open source projects like this come out, not because of the projects themselves, but because it makes the appliances they replace drop in price on the used market. finally, an evertz msc5700 for my very own home

An atomic clock? It's everything I've ever wanted! It will finally ensure I am on time for work. I always end up 1 ns late. Got written up for it too!

this card is doing the rounds for sure, just watched LTTs vod in it.

You're making me nostalgic, Jeff. Setting up NTP / XNTP on our network was my first duty wayyyy back when I got my first job as a sysadmin. Stratum 3 or maybe 2 was about as close as I got, though. Everybody needs accurate time, but they don't realize it. Also +1 for the Technology Connections comment. Very meta.

Please don’t let Red shirt Jeff near the atomic elements. We would risk too much to the North American continent.

Jeff, you never fail to amaze me. I'll be looking for more on this. Great subject.

Good job. As usual, rewarding new vid notification. Always interesting, topical, and "in the end -- funny". Thanks! Keep on keeping on.

Once again, Jeff, you provide a thought-provoking video which has me spending even more time reading through the debates & information in the comments. I'm grateful for the level of engagement that you have with your viewers, as well as as the way in which you accept corrections when additional information is presented by others. Yours is one of my favorite channels, providing both information & humor. I wish you a long & successful run.

Your humor and great work is, in my opinion, the best “family friendly tech channel”. I am eternally grateful for all your great work. I will keep sending you, and love ones, endless great wishes and blessings.🙏🏻

Very nice Jeff, as always. Thanks for the video.

I love the Technology Connections reference. It is great when people reference other channels, especially when they aren't in the same category of films.

The Rubidium unit on the card generates a 10MHz TTL clock. I have working Symmetricom Rubidium clocks that were bought a fraction of the $700 for the Microsemi unit so I think I'll go head and build one of these and connect it up to my existing 10Mhz TTL reference. Thanks for sharing, Jeff. Oh, and this is the best coverage of this device I've seen to date.

Thank u sm I rlly need this video, I’m working on an amateur global radio interferometer and I needed a way to integrate the atomic clock mechanism for data recording… ur a lifesaver

Another typically informative video! Thank you!

I work as a tech support field engineer for a major telecoms provider. Our entire network is synchronised to 3 Caesium clocks, cross referenced to each other and with GNSS receivers. We distribute this sync to our customers, most of whom have no idea of the ramifications. However we have one customer who are halfway through migrating their entire platform from TDM (i.e. E1 2Mbps circuits), to Ethernet. Because of the mixed technologies, their services are critically sensitive to clock jitter, and we are spending a fortune in analysing, adapting and managing their circuits to reduce these issues. I have been using Symmetricom Rubidium / GNSS test equipment as reference clocks to monitor their circuits, and the tolerance levels are so miniscule. Great video.

When i saw Linus and Ians viodes i was think if it was possible to run it on the raspi and i am happy to see that you did :D looking forward to more videos about time :D

That's pretty cool. I just picked up an HP5065A, an old school Rubidium frequency standard. Lot of cool things you can do with a super accurate clock.

11:08 Loved it!

Already gave you a like, but the Pirates! reference earned it all by itself.

So this is the third video I watch about this time card, yet you've added a ton of new info which I was not aware of. Like how Linux identifies the card, or that PTP requires hardware support on the network interface to work. I got a bit more excited about the possibilities this card offers. I was stuck in my head thinking on the database level only, that you can organize transactions in such way that you can essentially use optimistic locking all the time and non of them will collide. As a developer I thought "yeah, that's cool", but it's the more practical use cases which opened up my eyes. I'm really looking forward for the next video in this topic :) Also, I was thinking the other day about making a GPS based NTP time server on my network from a Pi, because "I can"(tm). GPS radios are not that expensive now. That could also be a good intro video to network time services. Shame on me, I never had the urge to look up how even NTP synchronization work, and PTP was completly unknown to me before this card. But it's an interesting topic.

Dude your videos are REALLY... REALLYYYY awesome

Nice video on the Rb + PTP + CM4 setup. Looking forward to support for the HW timestamp in Broadcom chipset. Although it's not as a sexy as the "atomic clock" rubidium setup, it might be nice to do a quick build on the CM4 with a normal GPS HAT +quartz RTC setup. It could still give you microsecond-level accuracy and with chrony's partial hardware timestamping support would be a quite capable NTP/PTP source for slightly lower accuracy requirements (like homelans :) )

When I got to my first submarine, we used 2 cesium clocks to provide reference signals to most of the equipment. The Cesium clocks weighed about 75 to 100 pounds and we had to take them to get calibrated every 6 months. They had a battery backup that lasted about 20 minutes, so we had to get them to the shop quick. On my last submarine we used a rubidium clock. Smaller and cheaper is better. We could sync it up with GPS ever few days to make sure it stayed accurate.

Wow there I thought having just got my RPi4 being an NTP server was great a time piece ... I do hope that card does not glow in the dark ;-) Nice video Jeff 👍

Accurate time is also important in electrical power networks and telecommunications. Great video.

I was waiting for this. And UKposts waited a day more to show it to me.

It's always nice to see you giving a shoutout to small content creators like Linus.

The puns are timeless :/

This piece of hardware is sooo cool!

Thank you for the video, I'm excited to see what you can do with this hardware. I have a few responses to your video: - The rubidium clock's accuracy is not based on it running at a higher frequency than quartz, but rather a more stable frequency. Temperature changes cause quartz crystals to change frequency more dramatically than rubidium - The 32khz crystal runs the real time clock (RTC), which can keep time between reboots. The RTC is typically ignored on the pi because it does not have a battery backup for the RTC, so the program fake-hwclock is used instead. The main system time comes from a counter in the CPU on the pi (driver is named "arch_sys_counter") which is driven at 54MHz - NTP can use hardware timestamping as well, and can reach microsecond to hundreds of nanosecond levels of sync in proper conditions

3:30 Many time standards (at least in my grandfather's collection) are 2-3U rack mount chassis, with about a quarter to a third of that space being the cesium beam tube in its high-vacuum housing and oven. The size difference is truly dramatic.

There is a Dallas DS3231 chip that packs a DTCXO. It is a lot less precise than atomic clock, but much better than a regular crystal, and much cheaper too. I have a Pi NTP server project that uses GPS for time base, a DS3231 for local timekeeping, and a STM32F030 as the governor of DS3231.

It was so damn pleasing to get a TC blinker reference!!! You don't even know! 😁😁😁

Great video 👍

Great Scott!

From a personal perspective, having a potential open source PTP clock as a grandmaster for 2110 is very exciting. On the other hand, I work for a company that used to provide a Raspberry Pi as a hardware solution for a broadcast product and well... it was not received very well by sales staff or customers, which I think is kind of a bummer. I'd love to run into these when commissioning broadcast facilities.

My job is working for one of the manufacturers that makes SMPTE 2110 gear, PTP is very important for doing uncompressed video over IP. It’s a neat field to be in.

This is so AWESOME I want to build my own stratum-1 server now. 🤩🤩🤩

0:05 I love the sound of cicadas. Here in Germany we don't have them, and they always remind me of our holidays in Croatia. Although the Croatian cicadas sound a lot different to yours, interestingly.

Another bleeding edge RPi episode. I'm interested in following where this goes.

I wish I needed one of these.

Good stuff you create, both professional and entertaining. I am planning to build a small server at home with some 10-20 Pi. How do you do and which Pi to chose? Is Kubernetes something to use? Which board is the best? Do you think you can do a video about this?

I used to use a similar system for calibrating the A2D in seismographs. It would output a square wave at a series of fixed frequencies. It was a lot bigger than your card there.

Nice video! There is a good option with GPSDO Gps disciplined oscilator. You can get one for about 100 bucks and hook it to the raspberry. It has several nanoseconds drift.

Hi Jeff, loved the video, watching you is always interesting but I was thinking… what about your vid for Wifi 6 access point on the AX200? Thank you!

I was waiting for Atomic Pi

Thanks for your clever explanation...clocking is everything in Digital :-)!

Thanks!

On the industrial manufacturing side, there are exceptionally few things that need more than 1/10 sec precision. The things that DO need to be coordinated are not done over a network, but rather point-to-point discrete signals. It is far faster to look for a rising edge of a 24V signal over 20m than it is to wait for network traffic to propagate to the devices. The PLC’s that run and connect things are themselves very slow compared to a netbook, so any PTP precision would go straight out of the window.

Hi Jeff, in our Mainframe we use a STP (sysplex timer Protocol) that Provider an Atomic Signal also. STP is a mix of the Hardware and the Software of the operating Systems. It is doing s nandshake, so that very Mashine measures the runtime of the Signal and corrects automatically the time to be correct. Do normal Servers are Build in the Same way)? Because, if not, Evelyn Server will run with different timestamps again.

Jeff, you could make a video about drying a towel and I'd watch it, probably to the end, and then click 'like' - please don't! Please keep the fascinating content coming. :D

Congratulations on the video. How do you know how many gps satellites can it sync to? Synching via ptp is one job, creating a non blocking switching fabric via multicast is another job. Would the rpi cm4 handle it?

If every self-driving car had one of these atomic clock modules in them, they could communicate with each other to warn about the position and speed of potential obstacles with a high degree of accuracy. They could also use it to coordinate traffic and reduce congestion.

10:04 an open source, simplified time synchronization platform could be made more secure and cross-platform. If adopted as part of a standard for communicating info between smart cars, we might see automatic safety features get a lot better. particularly in traffic streams where several smart cars can respond to each other predictively. Autonomous and maybe semi-autonomous caravanning also becomes more practical.

My last job we used the GPS receiver on a small outdoor radio to let it run as a mini GM clock, the proper big Grand Masters were so pricey there was quite a bit of customer interest. I'd bet they'd be even more interested in a Pi solution.

Many cristals and oscillators are running at a high frequency (dozen of MHz) and are actually precise. And they can be calibrated, even in software. The problem is not the low frequency but environmental changes in temperature (like you said) but also voltage that make them drift at runtime and unpredictively.

Timing is everything.

2:43 I see you there corner text that is a critical factor in the story

There's also another option. When the atomic clocks send their signal on local positions on eart you can do differential GPS with centimeter accuracy. Would may be a genius projects out of the ordinary.

To actually sync the clock in a data centre over the network you need a support from network devices. You mentioned that the card does not have the support yet but it is only software. Well many networking devices also do not have hardware timestaming. This is actually a heavy topic if you want to dive into it. For 5G application for example the accurate time is used so multiple base stations can send data over to a handset at the same time. There are multiple options to distribute time over the network the first one is via Synchronous Ethernet links and the second one is EEE 1588v2 PTP Boundary Clock. Many if the telecom providers use the second option as the hardware is cheaper. Same as on your cards the vendors like Broadcom created ASICs with support for hardware timestamping.

audiophiles could be interested in this clock to be used as master clock for DACs.

Jeff, Im curious what the issues are that prevent you from using NTP on your Chicago server?

My grandpa helped pioneer CSACs! I have one of his 10mhz frequency standards and it's rock solid. He still fools with cesium beam tubes using a raspberry pi for logging the data

Talking of interfacing PCIe stuff to the Pi4, can you do a video on using the Pi4 to drive a GPU for grid computing. Some people might be thinking crypto here, but my interest is for BOINC grid projects like Rosetta, or Folding@home.

the field of metrology uses highly stable and calibrated measuring equipment. this device promises a more widespread adoption of such science, which i think is a very exclusive club at the moment. Having this card run on a PI really makes this field in science more accessible to a larger demographic therefore helping further the research and opening up more opportunities.

That's just a little more accurate then what I personally need right now but maybe I'll need something like that next week.

Interesting video :) Small bit of feedback on editing, you are putting text near the bottom of the video which disapears quickly which is normally fine as you can pauze vidoes. However due to the position of the text the youtube video controls cover it when the video is pauzed.

Nice call out to the synchronized blinkers

We use an array of AC's all around the world interlinked for NASA, correlated to our telescopes to determine the wobble of the earth. The timekeeper is Dr. Phillip Arctender(really...birthname). A polar shift potential is high. Loss of Antarctic ice is prime factor. Nice to know we have it on a pi.,jpk

It's also used in the test & measurement industry when one has to distribute the same 1PPS ,10Mhz sync and PTP time domain over a dozen hundred meters with as minimal drift as possible. Mostly for making time sensitive measurements in sync across distant data aquisition points of a distributed system. Symmetricom is a well established and known name on the market. Ofcourse this card will bring a more affordable solution to smaller companies and even individuals. Hurrah Time Appliance Project!

Oh yes, it's about time!

I've watched a handful of your videos. This is the one that really got me. Our fiber build is running ethernet frames and keeping a very good clock is a new thing i've had to even think about. Very good stuff very boring topic like NTP and DNS no one really cares until it doesn't.

If you have the antenna well positioned, you might be able to run an NTRIP server. You can help people nearby improve their GPS accuracy.

Thanks for this project! Just wondering: Are you overstating the accuracy of the the SA.31m? Datasheets for the Microsemi SA.31m, SA.33m and SA.35m (along with the SA.45s) imply they all have an accuracy of '±5.0E-11 accuracy at shipment', while Microsemi vendor Sparkfun says: 'That puts the SA.35m Miniature Atomic Clock in the picosecond category of eight seconds per 31,689 years. Said differently, the MAC loses a second every 4,000 years or so.' Then again, I may not understand the long-term accuracy.

Also if you are going with the hardware timestamping route, use level 3 multicast first, ie. UDP. The ethernet multicast can be tricky if there are multiple switches or routers that don't support it.

In Europe we have DCF77. A cesium based signal from the hart of Germany with a range of about 100 miles or 1500 km. It the reference for all of Europe. Trains, postoffices etc. You can get receivers for home use as well.

Lol, love the tech connections reference. And the bad puns.

Thank god keept all this material in side the earth .

For the vast majority of users, a version of this at a fraction of the cost with ONLY the GPS system - and with backup to other NTP servers on the internet. Selling such a simplified version would be a real money-spinner, and provide easily sufficient precision for the vast majority of PC or LANs, and potentially increase the number of available stratum 1 NTP servers available in the pools to the point where the load on each would be insignificant. Such a basic GPS/PPS PCIe card (with drivers for all current operating systems) is a major missing link. Once you get distribution around a variety of devices on a network, NTP is quite sufficient. PTP is major overkill for almost everything we do at less than data centre or physics laboratory level.

I liked your outatime joke and the shaun the sheep clip.

Thanks for adding actual captions for the Deaf and clear explanation.

Issue with time drifting will likely to be with the virtual environment had it happen on mine when the virtual machine was being throttled but the problem was the time clock was linked to this in some way (usual fix is to change the high precision timing settings turn it off or on depending on the setup)

This is an interesting topic and one that I have long term experience with. Back in the day, we used WWV as one primary time reference. I'm having a hard time understanding why I should care about the differences between these references and NTP? What is the to gain in the specific examples you presented?

wow man. this is a very pun-heavy video. good job

Installed a 1 Rack unit GPS NTP at Bell Labs/Telcordia. Need to have the antenna run to the roof. Hmm would the ham station have been easier? Would it have been allowed on the corporate LAN?

Wow, so if the PHY hardware on the CM4 supports hardware IEEE1588 timestamping, would real-time protocols like AVB work when software support is enabled? That would make the CM4 much more useful in automotive and AV applications.

Curiosity: mechanical watches (the type with the torsion pendulum - wristwatches) was created to know the longitude! It required a sun dial to do that, though. another: never had an iPod - still have my Sandisk mp3/ogg/flac player, though.

Show us how to deploy a low cost array of radio receivers at known locations, each equipped with time cards, and each on a network so they can be remotely tasked to receive a specific radio frequency being transmitted from an unknown location (e.g. from a drone). The receivers would then send the peak signal spike times back to a command unit, which then geolocates the transmitter using TDOA(?).

We would love to see a update to this timecard to see how it advance in software or hardware.

I have a few atomic clock modules. I need to figure out how to use one to make my own atomic clock.

There is actualy a use for all clocks having a time card like that…. Temporal accuracy is necessary for self driving cars to cooperate creating a more efficient network. Being half a second off when deciding who is going to do what when at 200 mph can and will have deadly conciquences. So for cooperative self driving to work you will need accurate clocks.

This is so cool...

I'm surprised you didn't use something like Manjaro Arm for the kernel aspect. But I also get not wanting to be on the leading edge of software.

For over a decade I have been aware of the systemic benefits of hardware clock module upgrades. These benefits go beyond synchronization issues, and improve board functions resolution and noise levels. Might there be some way to rig this clock to REPLACE the clock functions that run processing and GPU functions? There might be significant benefits to be realized!

9:35 I think you meant to say that Red Shirt Jeff has barely scratched the surface of the card...

Key use for this is transactional analysis, stock trading etc… minutes give 60 transaction windows per hour, seconds give 3600 transaction windows per hour. The rubidium source allows more time slots per hour, hence more transactions per hour executed. I won’t list assumptions etc.. you get the idea.

Yargı reformu paketi: judicial reform package. I didn't expect to see something in Turkish.