Hacker News Reader

Comment by nutcracker46 | Hacker News Reader

WWV, WWVH, and WWVB are more than charity for timekeepers. They distribute time and frequency, traceable to a national standard, for one leg of "positioning, navigation, and timing."

Before GPS and the internet, numerous services depended on those signals. I would argue that now, we have positioning, navigation, and timing from multiple satellite systems (and a phone network providing excellent time & freq references derived from satellites). We have internet time synced to atomic standards and satnav. All of the modern references are more precise, accurate, and stable than WWV, WWVH, and WWVB.

As to devices which sync from WWVB, there are gadgets which can get GPS time and transmit an LF signal for syncing those devices. No problems, ladies and gents, you've still got time.

View on HN

I made one of these GPS -> WWVB simulators a couple years ago. There's a short write-up here, in case anyone is interested in reading about it: https://www.anishathalye.com/2016/12/26/micro-wwvb/

There are also some neat iPhone apps that use the audio circuitry to produce a low-power signal that can be picked up by radio-controlled clocks that are close by: https://itunes.apple.com/us/app/clock-wave/id1073576068?mt=8

A couple people mentioned the FCC and licensing issues in the comments below. As far as I know, as long as you're transmitting at a very low power (40 µV/m as measured at 300m), it's okay. This should be fine for personal use, but won't work on a municipal level.

Dude! That's freaking awesome. I've been wanting to set up a GPS-based NTP server for a while, but haven't gotten around to it yet. I'll have to read through and take a look at the transmitting equipment you used; adding WWVB to it would be awesomesauce.

Not bad! While reading the article the thought occurred that if WWV were eliminated then this would be a good opportunity for a smart phone app to pipe a GPS derived time standard emulating WWV format into a < 100mw (Part 15) 5, 10, or 15 MHz attached transmitter. And the idea was already objectified.

The Russians still equip their navy with shortwave. There’s a reason for that.

In any sort of conflict, GPS will be gone in hours.

The services you described as being dependent on these stations cannot necessarily be upgraded to use internet or satellite time.

There may be an interesting market not only for simulated WWVB but WWV / WWVH if someone absolutely needs to sync from HF. Those HF signals are notoriously unstable in phase, so a locally simulated signal may actually be better.

Here's an example of work on simulating WWVB, not yet in mass production:

https://sites.google.com/site/wayneholder/controlling-time.

He could use a precision frequency source if a precise 60 kHz was absolutely necessary.

I’m not sure what you mean by “locally simulated”. If I need to run this in my house, I now need to deal with a new device when my wall clock would have continued to work by itself before. If this needs to be done at the city level, then I now need to depend on someone providing a municipal service that needs to work consistently and reliably, which I am less confident that a city can run over the federal government (though, considering this incident, maybe I’m misguided?)

There’s also the licensing issue. You can’t just start broadcasting on that frequency. The FCC would have to assign it to you, or start up a licensing scheme.

If the lawmakers were smart, they would make an explicit allowance for micropower transmitters on those frequencies in perpetuity. I wouldn't get my hopes up though.

It's not the phase stability that's important, but the accuracy and drift over time.

Local service for houses or buildings could be provided service with limited power signals under rules for low power devices / FCC Part 15. Yes, you would need hardware to get your satnav (or mobile phone) signals and create the replacements for your LF/MF/HF dependent devices.

You have to ask yourself, "Where is the point of diminishing returns in retaining dependency on signals like WWV / WWVH?"

By the way eLoran will probably be the terrestrial back up for GNSS based position / navigation / timing. Also, if we get to the geopolitical state of satellites being destroyed, there will be a truckload of larger problems to worry about.

Any nation with the hubris to destroy GNSS birds deserves the nukes they suffer in return. Any nation who lets it happen, because the leader is numbnutted, deserves to suffer a breakdown for not being more mature in managing its geopolitical situation.

Fifth Risk indeed.

Is eLORAN still actually happening in the US? Since we shut down our LORAN transmitters a few years ago, I assumed the plans for eLORAN went out the window with it.

AFIK, everything is going to GPS and ADS-B.

I would buy one in a heartbeat if true. I moved and neither of my watches (one Citizen and one Seiko) can get the Colorado signal anymore from the Northeast USA. But as other posters point out, I cannot imagine the FCC would allow those devices. But, OTOH, the propagation characteristics of any small device/antenna running at 60kHz would be abysmally bad and perhaps unworthy of notice. I would still not bet my several FCC licenses on it though.

Do any of these satellite systems work inside a building without running antennae to the roof?

Window antennas work fairly well, but a roof mounted antenna / preamp is far more reliable.

Reply on news.ycombinator.com