HFU HF Underground

Loggings => HF Mystery Signals => Topic started by: ka1iic on December 11, 2014, 1631 UTC

Title: 15710 Khz USB 1619 UTC 12/06/2014
Post by: ka1iic on December 11, 2014, 1631 UTC
15710 Khz USB 1619 UTC 12/06/2014  signal was S7 to 8.

Audio file is here:

http://www.vincewerber.org/swl/DAT%3f-15710KHZ-USB-1619UTC-12-06-2014.wav (http://www.vincewerber.org/swl/DAT%3f-15710KHZ-USB-1619UTC-12-06-2014.wav)

Image file is here:

(http://www.vincewerber.org/swl/DAT%3f-15710KHZ-USB-1619UTC-12-06-2014.wav.png)

This signal is intermittent maybe be heard once an hour or less or several bursts can be heard within a much less time.
Title: Re: 15710 Khz USB 1619 UTC 12/06/2014
Post by: Token on December 11, 2014, 2005 UTC
This is improperly tuned MIL-STD 188-144A ALE, Automatic Link Establishment.  Because it is not tuned correctly I cannot say who it is, but I assume it is on the FEMA F50 frequency of 15708 kHz USB, so it is probably a FEMA station.

What you have here was likely a "sounding", a transmission sent so that all the stations in a network can know the current status of a potential link on that specific frequency.

Here is an example of the same kind of signal correctly tuned:  https://www.youtube.com/watch?v=RKlLW_J8kEU

T!
Title: Re: 15710 Khz USB 1619 UTC 12/06/2014
Post by: ka1iic on December 11, 2014, 2109 UTC
Thank you Token... I knew you'ld have an answer :-)  kudos!