Here’s a timely reminder for all you would-be revelers out there: Be careful with your countdowns this New Year’s Eve. There will be a little extra time to bask in the glow of a retreating 2016 — or curse its name, as the case may be.
Whatever your inclination may be, one thing is certain: Before the year is out, the world’s foremost authority on time will be adding one more second to the clock.
In a bulletin released this summer, the International Earth Rotation and Reference Systems Service, or IERS, said it would be necessary to introduce a “leap second” at the end of December. Timekeepers use this added second much as leap years are used — to bring the world’s atomic clocks in sync with the Earth’s own distinctive rhythm, which in this case is determined by its rotation.
This leap second isn’t the first. Since 1971, the world has added leap seconds with some regularity — typically every two to three years — and the latest leap second was added only last year, in June.
Last year, I recorded the 2015 Leap Second via WWV–click here to read that post. Though such a subtle change, it is fun to hear that extra second added. I plan to record the full 31 meter band New Year’s Eve–hopefully, I’ll also catch the 10,000 kHz WWV Leap Second!
With all of the Star Wars: The Force Awakens hype going on, I remembered that, as a kid, I thought I heard WWV in a scene from The Empire Strikes Back.
I looked through some video clips of the movie online and discovered it again this morning: I heard the WWV-like sound in the Battle Of Hoth scene. [Update: RadioGeek suggests this may actually be CHU’s date pips.]
I decided to record the leap second on as many shortwave time station frequencies as possible. The only viable options for me–based on time of day and my reception location–were the WWV frequencies 10, 15, 20, and 25 MHz, and CHU frequencies 7,850 and 14,670 kHz.
I was able to monitor four different time station frequencies simultaneously on the TitanSDR Pro. (click to enlarge)
Unfortunately, HF propagation was very poor yesterday, so the higher WWV frequencies–20 and 25 MHz–were completely inaudible, as was CHU on 14,670 kHz. There were numerous thunderstorms in our area, so static crashes were prevalent.
Still, since this was a first attempt to record a “leap second,” I didn’t want to take any chances. I had the Titan SDR Pro monitoring and recording two CHU and two WWV frequencies [screenshot], the Elad FDM-S2 recording WWV on 15 MHz [screenshot], and the WinRadio Excalibur on WWV’s 10 MHz frequency, as well as recording the whole 31 meter band spectrum [screenshot].
In the end, the strongest frequencies I captured were CHU on 7,850 kHz and WWV on 15,000 kHz. WWV on 10,000 kHz was much weaker than normal and the band was quite noisy–still, it’s readable, so I included this recording, too. Recordings follow…
The sign above WWV’s primary 10 MHz transmitter (2014).
All of the recordings start just before the announcement of 23:59 UTC.
WWV added the extra second and higher tone, then continued with their top of the hour announcements, including a note about leap second (which begins after the 00:04 announcement). CHU simply injects a one second silence before the long tone.
One interesting note about the 10 MHz WWV recording above: I believe I may be hearing BPM China in the background. I’m curious if anyone can confirm this because I don’t know BPM’s cadence/pattern well enough to ID it.
Did you record a shortwave time station as leap second happened? If so, please comment, and feel free to share a link to your recording!
One of four WWV time code generators in late August, 2014
Tonight, for the first time in three years, we will experience a leap second. What is a leap second? Wikipedia provides a concise explanation:
A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time, or UT1. Without such a correction, time reckoned by Earth’s rotation drifts away from atomic time because of irregularities in the Earth’s rate of rotation. Since this system of correction was implemented in 1972, 25 such leap seconds have been inserted. The most recent one happened on June 30, 2012 at 23:59:60 UTC. A leap second, the 26th, will again be inserted at the end of June 30, 2015 at 23:59:60 UTC.
WWV’s Matthew Deutch with WWVB antennas in background
I wrote Matt this morning to ask what were his plans tonight? His reply:
“The leap second happens at 0000 UTC tonight, which is 6:00 pm here in Fort Collins. All of the programming took place at the beginning of the month, so the equipment is armed…we just sit back and watch for the leap this evening.
Even though it is automated I hang around the station to make sure everything goes smoothly at the critical moment…”
Matthew closed his message by wishing me a “Happy Leap Second.”
Back at you, Matt! We hope that second leaps as smoothly as you’d like!
Not to put Matt on the spot, but you can listen to WWV (or the atomic clock of your choice) make the leap second tonight at 00:00 UTC. As for me, I’ll hop on 10 MHz and 15 MHz to hear (and hopefully record) the extra “tick.” At the end of this post, I’ve provided a list of time stations for your convenience.
Happy Leap Second!
WWV 20 MHz Collins transmitter
List of shortwave radio time stations
CHU Canada: 3330 kHz, 7850 kHz, 14670 kHz
BPM China: 2,500, 5,000, 10,000, and 15,000 kHz
HLA South Korea: 5,000 kHz
BSF Taiwan: 5,000 and 15,000 kHz
WWV (Ft. Collins)/WWVH (Hawaii) United States: 2,500, 5,000, 10,000, 15,000, 20,000 and 25,000 kHz
I quite often see a spike in the evening on 4996 khz. From the listing, this is suppose to be RWM, in Moscow, a time signal station.
When I listen on remote receivers in Poland and Denmark, I do not hear time pips, but rather just hash.
On my Perseus, I can watch the spike go up and down each second. This makes me think it is caused by WWV. However, the 29th second seems to make the spike move up, even though WWV doesn’t have a pip at second 29. The remote receivers in Europe that I just mentioned do not have any time pips being broadcast. Does WWV cause a signal on 4996?
Can you shed any light on 4996? Should we be able to hear RWM in the Eastern US?
Good question, George, and I’m hoping a reader can shed some light on what you’re seeing on the spectrum display. I’m not sure what could be causing the 29th second spike unless it’s WWV transmitting a sub-audible tone.
Want to catch WWV–the Fort Collins-based time station–on a frequency they haven’t used since 1977?
The National Institute for Standards and Technology (NIST) has sent out a press release stating that, as of April 4, 2014, WWV will resume broadcasting on 25 Mhz for a limited time.
Full details follow in their press release:
NOTICE: Experimental 25 MHz WWV Broadcast
As of Friday, April 4, 2014 WWV has resumed broadcasting on 25 MHz on a limited, experimental basis. The broadcast consists of the normal WWV signal heard on all other WWV frequencies, at the same level of accuracy.
Current 25 MHz Broadcast Specifications (subject to change):
Schedule: variable; as an experimental broadcast, the 25 MHz signal is not continuous. It will typically be on the air from approximately 1500 – 2100 UTC Mondays through Fridays, but may operate outside these hours as well. The broadcast may be interrupted or suspended without notice.