PIPs 2018-04-19 22:45 UTC

[GC]

PIPs active on numerous frequencies

PIPs were already active when I first them at 2018-04-22:45UTC

Pulse width of the several frequencies I measured is 64ms. PIP repetition rate is once every three seconds.

when viewed on the waterfall of a SDR, adjacent PIPs seem to in or at least very close to being in sync

signal strength is quite strong  S9

Frequencies:  (all frequencies in kHz and is CARRIER frequency, tune -1kHz for USB)
5970
6240
6330
6420
6720
6820
6920
7020
7460
7570
7680
7800
7920
8040
8160
8280
8400
8530
8660
9050
9190

still active at 2018-04-19 23:25UTC

cheers, Graham near Ottawa Canada

[GC]

went off the air for approximately two starting at 2018-04-19 23:27UTC, returned at 23:29:20.

So far, I have only noted a few periods where a PIP was missing but I have not noted any double pips.

cheers, Graham near Ottawa Canada

 

[GC]

I checked the frequencies as noted in this thread (by Traveling Wave) :

https://www.hfunderground.com/board/index.php/topic,41886.0.html

but nothing was heard on these frequencies

[GC]

PIPs appear to be off the air when checked at 2018-04-19 23:45UTC

cheers, Graham near Ottawa Canada

[Token]

Check my list of freqs here for other possibles in this series  https://www.hfunderground.com/board/index.php/topic,41560.0.html

ALso check here for some past receptions of the Pips Network, but the list is way out of date with no newer receptions on it, I really need to update it.  If you look at the very first entry, for April 18, 2012, you should find a very similar list of freqs to what you heard.
 http://www.tokenradio.net/Radio/SharedFiles/PipsFreqs.htm

By the way, the Pip should probably be 62.5 msec long, however multipath smearing can drag out the falling edge of the pulse.  In the early days of this signal it sometimes varied the pulse width a bit, but for the last few years has been very stable on a few lengths.

T!

[GC]

Thanks Token.

I measured pulse width on one of my recordings from last night - 62.5 it is, all depends of course where you place the start and end and with enough of wiggle you get 64

Perhaps the 1 PPS PIP signal we occasionally hear is not quite the 16ms I have been measuring.

I have seen you list of frequencies before and use it as a reference. When I find the PIPs active I search down to 2MHz and up over 10MHz  but so far have not heard them below about 5MHz or above 9MHz - perhaps I just don't have the propagation at those times.

I have been searching the FCC database of experimental (and other) licencees that may have been assigned these frequencies but so far I haven't stumbled cross anything similar. The Canadian Industry Canada licence system is not as friendly but regardless I haven't noted anything similar.  Of course it wouldn't be listed if it was military.

Indeed and interesting mystery.

cheers, Graham