Pips network up, multiple frequencies, 1403 UTC, 09 Oct, 2016

[Token]

The oddity Pips network is up today, as it was yesterday.  Noticed it at 1403 UTC, 09 Oct, 2016, not sure how long it has been up today.  0.125 second long dit every 6.0 seconds.

(edit) This set off air at 1513 UTC.

6450
8700
8975
9050
9225
11025
11150
11200
13200
13400
13800
14400
15100
15550
15625
16000
16200
16725
17175
17475
17775
17925
18050
18450
18625
18675
19075
19300
19350
20050 ?  Related to 20400?
20250
20400 ?  May be unrelated to Pips
20550
20900
20950 ?  Related to 20400?

Freqs noted so far, will probably find more and add to the list as found.

T!

[ChrisSmolinski]

Copying most of those frequencies here in MD. For some background on this network, this older posting is useful: https://www.hfunderground.com/board/index.php/topic,13529.0.html

[flexoman61]

Is this similar to Frequency Hoping like the Military uses?

[Token]

Is this similar to Frequency Hoping like the Military uses?

No, there appears to be no data on these pulses.  Different pulse lengths and spacing have been used, but todays was a 0.125 second long pulse sent every 6.0 seconds on a given frequency.

These pulses sequence up in frequency, starting on the lowest, then to the next highest, then the next highest, etc, from bottom freq to top freq, then restart at bottom freq.  With a 6.0 second periodicity and a 0.125 sec pulse that allows for 48 frequencies in this group.  However, there appears to be two sources, so you can sometimes find more than 48 frequencies in use.  By comparing the timing of any two adjacent frequencies you can tell if they are both from the same source or not.

Occasionally you will find one freq with both sources on it, then the timing differences and propagation differences make it clear there are two sources at work.

T!

[flexoman61]

Thanks T, I wonder what this is used for?

[Token]

Thanks T, I wonder what this is used for?

Best guess is that it is some kind of ionospheric research tool.  But like I said, that is a guess.

T!