WWV time signal stations on the chopping block

[Alan Georges]

You can read full details here:
https://swling.com/blog/2018/08/information-from-the-nist-regarding-possible-closure-wwv-radio-stations/
TLDR version: Next year's budget for the NIST has their time signal broadcast funds zeroed out.  This includes the WWV & WWVH shortwave stations, and the longwave WWVB automatic clock synchronization broadcasts as well.  Total per-year cost of these broadcasts is $6m.

These stations provide not only a time signal, but an equipment calibration standard and set of shortwave propagation beacons too.  Some are calling this a "nostalgia and legacy system," but as a ground-based backup for GPS time signals, $6m is a drop in the bucket.  Furthermore, we're not sure how many embedded systems rely on these signals for synchronization, so in the event of a shut-down we may (stress may) be facing a sort of mini-Y2K situation.  At very least, that clock way up high on Grandma's wall will start drifting, and she'll be bugging you once a month to come over with a ladder and set the darned thing.

It is $6m dollars, and I'm all for cutting the Federal budget to the bone.  OTOH, this is into the bone right here, and it divides out to a big $0.02 per person.  And, unlike so much Fed spending, this one is (sort of) authorized in the Constitution:

To coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures;

  Works for my libertarian soul.  If you are inclined at all to write your congresscritter, now's a pretty good time.

[iam4liberty]

This is a bummer as It is my favorite time sync as my little handheld yaesu can tune multiple of the signals.  But i do understand it.  It isnt just redundant with GPS, it is redundant with over ethernet synchronization too.  And that can comes directly from the NIST.  Syncing can come through app, browser, or through OS via time server.

And we are in a time reference rennaisance.  For a few hundred dollars an individual or institution can buy an oven controlled crystal oscillator based clock calibrated at factory to an atomic clock which is accurate to seconds within a couple decades.  Or you can buy an atomic clock itself (not signal synched, an actual atomic clock).  My christmas wish list has a brg precision double oven multi-zone (local, utc, sidereal) on it.  But I dont think I have been that good.   

http://www.brgprecision.com/products/accuracy.php
http://www.brgprecision.com/products/time_zone_displays/TZfixed.php

Heck, for about a hundred dollars one can buy a high accurate quartz wristwatch with accuracy to under 20 seconds a year.  Heck, a saw a bulova uhf (ultra high frequency) at walmart for $120. 

[FreeLancer]

Manually syncing all my clocks and watches is going to f-ing suck.

[iam4liberty]

Manually syncing all my clocks and watches is going to f-ing suck.

I am sure some crafty individuals will make low power transmiter hooked to raspberry pi with ethernet sync to send super low power signal themselves.   

[FreeLancer]

I'd do it.

As long as it doesn't take a 5000m dipole.

What kind of antenna would it take to mimic WWVB's 60khz low power signal at home? 

[Alan Georges]

What kind of antenna would it take to mimic WWVB's 60khz low power signal at home? 

This project just used a short wire:
https://www.instructables.com/id/WWVB-radio-time-signal-generator-for-ATTINY45-or-A/
and this project re-purposed a loopstick:
https://www.anishathalye.com/2016/12/26/micro-wwvb/
At low powers and short ranges, antenna matching isn't any big deal.

So, it's been done before.  If WWVB goes SK, I'm sure there'll be a small cottage industry selling "clock setters" on eBay.

[Carl]

WWVB could be synced and transmitted over power-line on a small budget.

[iam4liberty]

Looks like there has already been a market for such devices driven by people in countries without signal reception (like Australia).  For example: https://unusualelectronics.co.uk/products/chronvertor/.  For some it can be done using just a PC and some wire.  http://www.jrcomputing.com.au/Set_Watch/Set_Watch_Auto.html  Very clever thinking here.

[Mr. Bill]

 

That's just brilliant.  Every household "atomic clock" becomes worthless.

I have a feeling this'll get reversed when the manufacturers raise a stink.  But we'll see.

[FreeLancer]

For some it can be done using just a PC and some wire.  http://www.jrcomputing.com.au/Set_Watch/Set_Watch_Auto.html  Very clever thinking here.

That’s pretty damn clever! 

Hands down the simplest way to at least keep my Japanese solar watches functioning as intended, post-WWVB. Clocks costing 10’s of dollars are less painful to replace than watches costing 100’s.

[iam4liberty]

I have a feeling this'll get reversed when the manufacturers raise a stink.  But we'll see.

In many ways it is planned obsolescence. The NIST, USNO, and others did an amazing job quantifying internet lag times to create algotithms that could synchronize times for the "internet of things".  Compare this to your radio syncronized atomic clock: https://time.gov/widget/widget.html 

The use of this technology has exploded and is being embedded in virtually every device.  The users of the broadcast service is so small in comparison.



I doubt most manufacturers mind much as people will just switch to devices using the other technology.  Heck, there may even be a bump in sales as people switch out.

[Carl]

  WHAT....and do without an internet synchronized toilet?

[iam4liberty]

  WHAT....and do without an internet synchronized toilet?

Toilet accuracy is very important!   

[FreeLancer]

I found an easy solution in a $2 iPhone app called Clock Wave

All you have to do is open the app and turn the volume all the way up before hitting a button on the screen to start transmitting the signal.  The clock/watch needs to be close to the phone speakers and no headphone/antenna is necessary.  There's an audible ticking noise when transmitting, but nothing too annoying. 

You have the option of specifying which of the 6 world time signal stations to emulate, or just leave it on auto and it will pick the appropriate one for the timezone the phone is operating in.  The only other setting you can change is whether it automatically stops transmitting after 10 minutes, in case you want to start the process and not wait around for it to finish syncing.

The three watches and cheap travel clock I tried it out on all synced within 4 minutes.  The signal strengths within a few inches of the iPhone's speaker was at least level 3 for all the devices and I had no problems syncing them all together simultaneously.

[iam4liberty]

Ah, fun app, Frelancer! There is a thread at the watchuseek forum.  Pumping it into a simple loop antenna (old AM radio or just coiled wire) seems to produce really good signal and no sound.



There is slso reportedly an app on android for watches which can receive JJY (Japan) signal.

[FreeLancer]

There is slso reportedly an app on android for watches which can receive JJY (Japan) signal.

That’s where I started, actually downloaded and ran it on a chrome book, but it’s all in Japanese and online instructions made it sound like the time zones on the watch would have to be changed to Tokyo and it just sounded like a pain in the ass.  So I replaced JJY with WWVB in my search terms and stumbled on to this app, which will do JJY, WWVB, DCF77, and whatever the other 3 are.

[iam4liberty]

That’s where I started, actually downloaded and ran it on a chrome book, but it’s all in Japanese and online instructions made it sound like the time zones on the watch would have to be changed to Tokyo and it just sounded like a pain in the ass.  So I replaced JJY with WWVB in my search terms and stumbled on to this app, which will do JJY, WWVB, DCF77, and whatever the other 3 are.

Sounds like a business opportunity for someone versed in android app development...

[FreeLancer]

Here's a video of the Clock Wave app synchronizing a typical clock:  https://youtu.be/eGasNo4zjbg

It's kind of funny because he predicts it will only take one minute to synchronize, and then has to fast forward through to the 3 minute mark before it actually happens.  That's consistent with my experience, where even my more reliably sensitive devices seem to stay in receive mode for at least 3 minutes before completing the sync process, and none that I've tested go past the 4 minute mark, although there are apparently some devices that are programmed to attempt synchronizing for up to 10 minutes before giving up.

[FreeLancer]

Here's a video from the developer:  https://youtu.be/T_f0-qj3R5E

It looks like his Casio synced in less than 3 minutes.

[iam4liberty]

Here's a video from the developer:  https://youtu.be/T_f0-qj3R5E

It looks like his Casio synced in less than 3 minutes.

The person on the watchuseek forum who used the loop antenna said this regarding time to sync:

Using the phone's speakers it takes about 5-7 minutes to get a successful update on any of the watches. I have an old AM loop antenna that I put a 1/8" phono connector on so I could plug it into the headphone port on the phone. Using this antenna the updates take only 1-2 minutes now. And I can update multiple watches at the same time.

Probably what is happening is that it is dropping one of the bits every so often and so has to confirm with another string.  would be interesting to see algorithm the watches use for checking stream.  I would imagine it would have an integrity check so the time isnt set by a faulty time read.

[Carl]

The person on the watchuseek forum who used the loop antenna said this regarding time to sync:

Using the phone's speakers it takes about 5-7 minutes to get a successful update on any of the watches. I have an old AM loop antenna that I put a 1/8" phono connector on so I could plug it into the headphone port on the phone. Using this antenna the updates take only 1-2 minutes now. And I can update multiple watches at the same time.

Probably what is happening is that it is dropping one of the bits every so often and so has to confirm with another string.  would be interesting to see algorithm the watches use for checking stream.  I would imagine it would have an integrity check so the time isnt set by a faulty time read.

Get a big enough antenna and you can synchronize the world   

[FreeLancer]

This guy ain't gonna be too happy about WWVB going away:  http://www.arrl.org/files/file/QEX_Next_Issue/2015/Nov-Dec_2015/Magliacane.pdf

[iam4liberty]

This guy ain't gonna be too happy about WWVB going away:

Great article. Thanks for posting. From ending statement he realized that it was being supplanted by newer technology but hoped it could still find a way to justify itself.  He suggested it as a back-up to gps for engineering and science projects but that is now superflous given NIST internet feed available from every internet connected device. 

While some may question the merit of employing WWVB as a frequency reference at a time when GPS-disciplined frequency standards are so ubiquitous, similar questions could be raised about the relevance of the Amateur Radio Service in a world dominated by cellphones and the Internet. The frequency standard described here employs a “purely RF” approach toward disciplining a local oscillator against an extremely accurate national atomic standard. It was developed not only to create a laboratory grade frequency standard, but to do so while pursuing a life-long interest and fascination with the underlying radio concepts that make such a process possible. Figure 21 shows a reception QSL that I received from WWVB in 2003.

While not a state-of-the-art device by twenty first century standards, the frequency reference described here will likely provide more than adequate performance for many modern engineering, research, and scientific purposes. For those possessing GPS-disciplined standards, this frequency standard can provide a reliable sanity check as well as a redundant backup.The recent changes made to the WWVB broadcasts by the National Institute of Standards and Technology have been unset-tling for some individuals. What these
actions reveal, however, is that while the WWVB primary role is changing, it is changing because its use is growing, and this growth will help ensure there is strong support for keeping WWVB on the air for
decades to come. See you in the next FMT[

Changing gears, here is another post from a person who made an arduino based time reference which updates its time from internet atomic clock servers and broadcasts the update signal for radio control clocks for about half a meter.  It keeps devices updated to within about 100 microseconds.

https://forums.watchuseek.com/f9/diy-haq-clock-1085096.html

I know the law allows for localized transmissions of rf like this on restricted frequencies.  I believe they measure compliance as x power y distance away from transmitter.  Does anyone know the rules?

[iam4liberty]

https://www.coloradoan.com/story/news/2018/09/22/fort-collins-budget-cuts-time-day-radio-broadcasts-could-go-silent/1352761002/

Cited petition failed to meet minimum signiatures: https://petitions.whitehouse.gov/petition/maintain-funding-nist-stations-wwv-wwvh

[FreeLancer]

I know the law allows for localized transmissions of rf like this on restricted frequencies.  I believe they measure compliance as x power y distance away from transmitter.  Does anyone know the rules?

Somewhere I read that the limit is 40 microvolts per meter at 300 meters.

[Bradbn4]

I am sure some crafty individuals will make low power transmitter hooked to raspberry pi with ethernet sync to send super low power signal themselves.   

They have and you can make a mighty fine NTP server based on that hardware.  All of the equipment including the Raspberry pi & GPS receiver is under 100 dollars.

Most if not all of the parts can be obtained from Ada Fruit & Spark Fun.  One of these days I will assemble the hardware and give it a spin.

So it is quite easy and sort of "cheap" to get a stratum 2 NTP time source. The only software defined transmitters I have found cost a bit of money. Ok, the transmitter it is not that expensive, but a bit more than I am willing to shell out of pocket right now. 

[FreeLancer]

Somewhere I read that the limit is 40 microvolts per meter at 300 meters.

Found it.

and this project re-purposed a loopstick:
https://www.anishathalye.com/2016/12/26/micro-wwvb/

Legality

Building a WWVB emulator involves transmitting on 60 kHz. In general, it’s not legal to broadcast on arbitrary frequencies at an arbitrary transmit power, because transmissions cause interference. Many parts of the radio spectrum are already in use, as allocated by the Federal Communications Commission (FCC).

Luckily, the FCC grants exemptions for certain unlicensed transmissions, as specified by 47 CFR 15. This is explained in some detail in “Understanding the FCC Regulations for Low-Power Non-Licensed Transmitters”.

Transmitters in the 60 kHz band are allowed, and the emission limit at that frequency is given in 47 CFR 15.209. As long as the field strength is under 40 μV/m
as measured at 300 meters, it’s fine. In my use case, I have the transmitter within a couple inches of the receiver in my wristwatch, so I don’t need to transmit at a high power.

[FreeLancer]

The WWVB broadcast coverage area is defined as those regions receiving a signal strength of at least 100 microvolts per meter:  https://tf.nist.gov/stations/wwvbcoverage.htm







WWVB Radio Controlled Clocks:  Recommended Practices for Manufacturers and Consumers (2009 Edition)

8.A. Receiver Specifications
Complete receiver specifications are beyond the scope of this document,
but the minimum goal of the manufacturer should be to include a receiver
and antenna sufficiently sensitive to work anywhere within the CONUS
during the nighttime hours.  We recommend that RCC products should
be sensitive enough to successfully synchronize to signals from WWVB
with a field strength of 50 μV/m, if the signal to noise ratio exceeds 20
dB.  The RF bandwidth of the receiver should be narrow, typically ±10 Hz
or less.

[iam4liberty]

Excellent information!

Had a little while to play around today so i thought i would make a replacement for my RF synched clock.  I have a rugged (waterproof, gorilla glass) but outdated android phone i wasnt using.  It came with a charging stand to act as an alarm clock and for years i used it as such.  So thought that would be excellent for an online (in my case via wifi) synched clock. 

First I had to root it so that programs could modify the time.  In android this is considered a security item so it needs superuser status to do.  After that i turned off the automatic time updating. I then added the ClockSync app from the play store.  This app connects to the atomic clock pool, measures network latency, and adjusts the system time accordingly.  I set it to update every 15 minutes at high precision which averages across multiple reads.  This keeps the time to within a guestimated 0.05 to 0.10 seconds.  Here it is next to my RF synched clock.



Now the reason i wanted to modify the system time rather than just display the atomic time was to enable the use of other clock programs.  One of my favorites is the Observatory Clock app.  This gives a lot of other times I use such as UTC, sidereal time (for finding stars), Julian Date, day number, moon phase, etc.  It outputs in a low level red which maintains night vision for star watching.  Since my setup still has a battery, i can just grab it when I go out watching.  I snapoed a picture and managed to get it right when changing (which isnt visible otherwise).



All in all this is looking to be a good option.  It should be a lot more reliable in updating than the RF clock during times when propogation is bad.  So definitely a lemonade out of lemons situation.

[FreeLancer]

Now the reason i wanted to modify the system time rather than just display the atomic time was to enable the use of other clock programs.  One of my favorites is the Observatory Clock app.  This gives a lot of other times I use such as UTC, sidereal time (for finding stars), Julian Date, day number, moon phase, etc.  It outputs in a low level red which maintains night vision for star watching.  Since my setup still has a battery, i can just grab it when I go out watching. 

That's a cool app! 


The closest thing I've been able to find in the iOS world is the Emerald Observatory.



I don't know what 90% of it means, but it's mesmerizing to look at, and it allows you to simulate various astronomical events.



On the WWVB front......




I got a Tecsun AM loop antenna and experimented with transmitting the Clock Wave app signal via the phone's audio jack.

Amazingly, I was able to sync all my devices at a distance of 25m inside my house, through one interior wall even, with the devices reporting the signal as full strength.  However, it appears the devices must be aligned within a few degrees perpendicular to the plane of the loop.  More than 5 degrees outside of that orientation the sync would fail, despite the devices reporting full receive strength of the signal.  I couldn't tell that adjusting the tuning dial on the Tecsun made any difference.

I had considered trying to make a larger loop antenna out of ribbon cable, but kind of doubt it's worth the effort, especially if it remains that directional.  Ideally it would be nice to have an antenna that was capable of 20 degrees either side of perpendicular, so I could put it at one corner of the house and broadcast the signal overnight and all the devices could sync in place as they normally do.