We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: Long Dashers, possibly similar to Pips Network, multiple frequencies, March 2020  (Read 661 times)

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 1917
  • Karma: +16/-0
    • View Profile
For at least 9+ years a type of transmission that I have called the Pips Network in my log has been periodically operation on multiple frequencies. There have been many loggings of this signal on the HFU forums, particularly in the Mystery, Utilities, and Other forums. Sometimes they are seen daily, sometimes it is months between being reported. I know there is more than one source involved, and I strongly suspect not all transmissions seen are related. There is one main network for sure, the one originally seen and for which the "Pips Network" name was coined, and possibly a couple other unrelated networks. However, they all have roughly similar habits, so they get logged under the same name in my log. What they are for is in question, I suspect that they (at least the original ones seen) may be some kind of ionospheric test or measurement signal, but that is a guess on my part.



The habits observed are typically that a dash or dot, sometimes long and sometimes short, is sent on multiple frequencies, from as few as 2 to up to 60+ frequencies. The pulses are not coincident in time, each pulse is sent on a frequency and the source then cycles to the next frequency on the list. Always to the next closest freq on the list. So the pulses/dashes cycle either up or down in frequency.



Often the pulse width and pulse interval are related, and sometimes that relationship defines how many frequencies can be used. For example a one second pulse might be sent with an interval of 15 seconds, or a 0.125 second pulse might be sent with an interval of 6 seconds. In the first case this would allow for up to 15 frequencies to be hit in sequence, in the second case it might allow for up to 48 frequencies to be used.



A slightly different version of this class of signals (in my logs, anyway) is one that uses few frequencies in relationship to the interval. In other words, it has time to do many frequencies but only does a few, but the other habits remain roughly the same. I am less convinced these are ionospheric tools, but it is still a good possibility.



One specific subset of this version includes a long pulse (over 2 seconds, 2.7 and 2.9 are common) and a very long interval (27 seconds seems to be common) on only a very few frequencies, and sometimes including a short burst of some kind of modulation at the beginning of each pulse.  I have called these signals Long Dashes in my logs.



For the past few days I have been following and recording this later subset. I typically see four frequencies in use, there may be more but if so they are not making it to my location. The signals are heard here in California and at the same time on remotes in Europe. A video of the other days signals here, at the time of this video I was aware of only 3 frequencies in operation, I now know it is normally 4+:

https://www.youtube.com/watch?v=elESMkHAwAw


They may sit on one set of frequencies for hours at a time, or they may change sets every few minutes.  The signal may be off air for hours at a time, or may run for hours on end.  One frequency seems to be normally near 12500 kHz, one near 11950 kHz, one near 9980 kHz, and one near either 6500 or 6700 kHz.  These freqs are loose, and I often find the signal +/- 100 kHz from those.  I hear the signals best in the mornings, and this may indicate Asian or Pacific origins.

T!
T!
Mojave Desert, California USA

Offline KM0NAS

  • Jr. Member
  • **
  • Posts: 33
  • Karma: +0/-0
  • Minnesota
    • View Profile
11950 is the frequency I find the most puzzling. Why right in the middle of the 25m broadcast band like that? It would seem that dropping down to 11550 or so would be a far better area and avoid QRM to an experiment if that is what it is.
*KM0NAS*
Kenwood TS-570D
Soft66RTL2
40 meter dipole @ 40' height
20 meter dipole @ 40' height
10 meter vertical @ 16' height
Beacon MN on 13562.8

Offline Josh

  • DX Legend
  • ******
  • Posts: 4068
  • Karma: +10/-0
    • View Profile
We do not encourage any radio operations contrary to regulations.

Offline KM0NAS

  • Jr. Member
  • **
  • Posts: 33
  • Karma: +0/-0
  • Minnesota
    • View Profile
It is just a two second carrier and then 27 seconds of silence. The TDoA sample is 30 seconds long. So basically you will only have two seconds of data to work with each time you try. I don't think you you'd get any meaningful results.
*KM0NAS*
Kenwood TS-570D
Soft66RTL2
40 meter dipole @ 40' height
20 meter dipole @ 40' height
10 meter vertical @ 16' height
Beacon MN on 13562.8

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 1917
  • Karma: +16/-0
    • View Profile
No tdoa?

The TDOA results have be highly variable.  Every time you run it you get a different result, and the plots are not tight.

Judging purely by propagation I am thinking Central Russia / western China / Kazakhstan kind of area.  Not exactly any of those, but kind of that area of the world.  The other day it was heard simultaneously literally almost everywhere outside of South America.  North America, Europe, South Africa, Asia, India, Australia, every remote I could find, but I could not hear it on any of the South American remotes.

T!
T!
Mojave Desert, California USA

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 1917
  • Karma: +16/-0
    • View Profile
A new video of this signal up, showing 5 freqs in use.  I suspect there have always been at least 5 in use, the timing allows for up to 9 freqs in use.

https://www.youtube.com/watch?v=vA9-F1-EQOg

T!
T!
Mojave Desert, California USA

Offline KM0NAS

  • Jr. Member
  • **
  • Posts: 33
  • Karma: +0/-0
  • Minnesota
    • View Profile
Long Dasher now active on 6484, 8999, 11980, 12499, 16199
15:59:46 UTC
Saturday, April 4, 2020
*KM0NAS*
Kenwood TS-570D
Soft66RTL2
40 meter dipole @ 40' height
20 meter dipole @ 40' height
10 meter vertical @ 16' height
Beacon MN on 13562.8