13560 kHz Time Signal ? 0100 UTC 15 Jan 2018

[Traveling Wave]

I found this time signal on 13560 kHz  a few days ago. I have checked it during different times of the day and its always a constant S7 in WNY. You will notice a double beep approx. 6 seconds into the sound file using CW mode. This occurs every 60 seconds. Anyone have an idea what it could be ?

[Rob.]

I am hearing something similar but faster beeps or dits. The longer dash does not coincide with the top of the hour or any other time during the minute that I can tell. Here at the CT/MA border it does fade in and out and is not always present. What I hear seems to beep a little faster than your recording.

[JCMaxwell]

It is constantly here in NC also.  Have no idea on its purpose.

[Josh]

If it's there day and night it's local, my guess is a very precise industrial application. But who knows?

[Traveling Wave]

Just found this video by MDK2. The same signal was reported on youtube a while back .... https://www.youtube.com/watch?v=cQh6ReSZ5jA
The signal still has the 55 beeps to a minute cycle.

[ChrisSmolinski]

Here's a video I just took showing a signal that I get here day and night, constant amplitude. So it must be fairly local.

https://www.youtube.com/watch?v=wqTrOn9IVEY&feature=youtu.be

[ChrisSmolinski]

And just after I recorded that... this other signal appeared, with short CW bursts every 3 seconds. Then it disappeared.

https://youtu.be/jK3R6bPFNVc

[Token]

Everywhere has these signals, and they are local typically, i.e. heard 24 / 7 regardless of propagation.  I think we had another thread on them a few years back.

I have never confirmed the source, to tell the truth I stopped looking after I realized they were so pervasive,but one possible source, has a signal very similar to this, is a cable security monitor used by multiple services.

T!

[ChrisSmolinski]

I've suspected leakage from the cable tv system. One of these day's I'll go mobile with the AFE822x and MacBook and see if I can DF it.

[Josh]

Yep, some cable systems leak like a sieve. Some of the diy folks use "screw on" f connectors in their home cable lashups, those have to be lossy and leaky at the same time. There's also that pervasive tv - generated signal, perhaps carried by leaking cable systems all over, on 14.317 or thereabouts.

[Traveling Wave]

I still find it interesting that the signal I tuned into in WNY had the same characteristics, 55 beeps a minute,as the MDK2 signal and he is located in Denver CO.

[Josh]

I also wonder if it's dsl related, lots of dsl modems (as well as the miles of telco lines that feed them) out there and they may be radiating stuff all over hf.

[Token]

At my location I can normally hear at least two different sources of these signals.

#1 is the most steady, always there, 24/7.  All of the specifications vary a bit over times, but right now the frequency is 13559.95 kHz.  The dits are each about 90 msec long and happen about every 995 msec.  That makes the rate about 60.3 pulses per second.

#2 I do not always see, and it is often weak enough that it can be hard to make out details.  Sometimes though it is very strong.  Right this minute it is as strong as #1 but has different parameters, it seems to always be a little different than #1.  Frequency is 13559.25 kHz.  The dits are about 65 msec long.  They occur about every 575 msec.  That makes the rate about 104.3 pulses per second.

But for both signals if I look closely at the pulses I see they are not a complete pulse.  For both #1 and #2 each pulse sounds like a single event, but each is actually made up of 3 smaller pulses with small gaps between them.  In the case of #1 it is one long pulse and two short pulses making up each "single" pulse to the ear.  In the case of #2 it is two short pulses and one long pulse making up each.

I don't know what these are, and like I said before, I kind of lost interest in them when I fund that no matter what area I visit I still hear them.  Typically the only place I do not hear them are in remote areas with no houses / communities around.  It is reasonably plausible to me they have something to do with some utility service that most communities seem to have.  A cable technician who is also a ham says they sound like a security system they use on their cable system.

T!

[Mixer]

I took my trusty Sangean ATS-909x for a drive. I set it on the dash of my Jeep (which has a handy tray exactly the right size to hold the radio), with the whip antenna partially extended. I tuned it to 13.560 in USB mode.

In my driveway, I heard nothing, but my Drake R7 upstairs, connected to an 80 meter dipole, consistently picks up at least two pulsed signals on the same frequency - very similar to what others have reported.

I live in a smallish city in upstate NY. I heard little when driving through residential areas, but started to pick up quite a few signals whenever I would drive past commercial zones.

In particular, I wanted to drive past the entrance doors of my local KMart, since they use an RFID tag security scanner right at the exit to detect shoplifting. As expected, this area (within about 100 feet of the entrance), produced an extremely strong unmodulated carrier - peaking at about S9 +20 close to the entrance but fading quickly as I drove away.

A similar unmodulated 13.560-ish carrier was noted near the entrance of a Walgreens, which has a similar theft detection system.

I heard pulsed signals at several locations, and found that these were coming from convenience stores with gas pumps. The signals were very strong at the pumps themselves. All of the pumps have standard credit card readers set up to read both magnetic stripe and chip-enabled cards. These locations all seemed to be generating pulses considerably faster than 55-to-60 pulses per minute though.

Driving back home, I started picking up a signal absolutely identical to those in several of the YouTube videos linked in other posts. These were coming from a small manufacturing company. I know that this particular building uses security badge readers for employee access. There is a badge reader panel at each entrance door, and arriving employees hold their company ID badge up to the panel to automatically unlock the door.

In short, I’m certain that all of the signals picked up by numerous individuals at widely separated geographic locations are strictly local in origin. No doubt any urban area will be awash in both modulated and unmodulated signals centering on 13.560 MHz coming from various RFID enabled systems at commercial establishments.

[Token]

In particular, I wanted to drive past the entrance doors of my local KMart, since they use an RFID tag security scanner right at the exit to detect shoplifting. As expected, this area (within about 100 feet of the entrance), produced an extremely strong unmodulated carrier - peaking at about S9 +20 close to the entrance but fading quickly as I drove away.

A similar unmodulated 13.560-ish carrier was noted near the entrance of a Walgreens, which has a similar theft detection system.

I heard pulsed signals at several locations, and found that these were coming from convenience stores with gas pumps. The signals were very strong at the pumps themselves. All of the pumps have standard credit card readers set up to read both magnetic stripe and chip-enabled cards. These locations all seemed to be generating pulses considerably faster than 55-to-60 pulses per minute though.

Driving back home, I started picking up a signal absolutely identical to those in several of the YouTube videos linked in other posts. These were coming from a small manufacturing company. I know that this particular building uses security badge readers for employee access. There is a badge reader panel at each entrance door, and arriving employees hold their company ID badge up to the panel to automatically unlock the door.

In short, I’m certain that all of the signals picked up by numerous individuals at widely separated geographic locations are strictly local in origin. No doubt any urban area will be awash in both modulated and unmodulated signals centering on 13.560 MHz coming from various RFID enabled systems at commercial establishments.

On the other hand, I hear these 24/7 at home in the desert and I am more than 4 miles from the nearest commercial building (a small Mom and Pop gas station) and more than 7 miles from the nearest larger size commercial building, Dollar General.

The signal I hear in remote, rural, areas is a bit different than the ones I hear near buildings / establishments with card key access or RF based inventory control systems.

I think this coming weekend some mobile SDR recordings are in order.  Remote locations and near businesses.

Regardless, this is an ISM band, and there is no telling what kind of signal might be squeezed into those bands.  I have seen power supplies, laser pumps, RFID, cable intrusion monitors, etc, all in these bands, and particularly in the 22 meter allocation.  I think the upshot is there is going to be a LOT of things that go beep and squeak there that we might never be able to ID.

T!