Wassup with Those Mysterious Russian Letter Beacons? - Part 2

When I wrote Part 1 of this recent BLOG topic, it certainly didn't occur to me that I would have so much more to say about it so soon.  It would seem that this is the fourth installment of my [seemingly] random thoughts on the Russian Single Letter Beacons (SLB's).

As reported in last week's 3rd post, the Kamchatsky "K" beacon has been recently observed altering its transmission ID, for at least a 3rd time in less than a month.  This weekend's observation got me to wondering what else may be going on with regard to this beacon network.

Saturday evening while listening on 7.039 for the "F", "K" & "M" Asian beacons, I almost missed

the "K" beacon because its format was even more different than I've ever heard it.  In the previous BLOG installment I raised the question of whether the Russian beacons run completely unattended, or are they in some way easily manipulated by human operators.  With the "K" beacon, someone is obviously changing the transmission content.

While considering material for this Blog entry, I checked out the beacon frequency list documented
in the previous Blog ([Click Here] to see it.)  I wondered what the Russian Letter beacons must sound like in Europe.  Remembering there is an SDR receiver in the Netherlands, it made sense to make
use of it's prime European location.

As shown in this Blog's opening graphic, the EU beacons were not hearable @NX6T and the
Asian beacons could not be heard in Europe.  In many respects, this observation was not surprising.  However what DiD surprise me was hearing a signal on the 7.039 channel not documented on any of the websites.  What was heard repeated over and over again was:
          "V V V  V V V  V V V  DE FDE2  FDE2 FDE2 AR" - [CLICK HERE] to hear this station.
What is THIS all about?  Some sort of traffic marker?  The station never stops the repeated transmission, nor does it transmit anything else.  There is no indication of QSX (listening for a
calling station).  Is this JUST another beacon?  Or, is there more to this station than just marking
a frequency?

As it turns out, it is a good thing a recording was made of the FDE2 - 3+ days later it is no longer heard on the ~7.039 frequency.  My observation suggests that FDE2 was deliberately run on that frequency and for whatever reason, the transmission was deliberately ended.

The more I learn about these Russian Single Letter Beacons, the more there is to learn. 
In the meantime, while these beacons seem to be used by Russians for propagation purposes,
they are also valuable to radio amateurs for the same purpose.

For the next part of this BLOG series, I'm going to listen in from other SDR receivers around the
globe to get a better understanding of how to leverage this free beacon resource.

Do YOU make use of the Single Letter Beacons?

What have YOU learned?