Further Investigations into those ubiquitous Russian Military Beacons

Over the last 9 years, I have written extensively about the ubiquitous Russian military beacons.  Recently, using those beacons during numerous radiosport contests, it occurred to me that due to recent Russian military escalations, we are overdue for an update on the status of these beacons,
at least the Eastern Asian ones.  ([CLICK HERE] to read some of those Blogs.)

In my thinking, there are two groups of Russian beacons: those based in North/Central Europe
and the beacon trio operating in Eastern Asia ("F", "M" & "K").  I first heard the EU beacons on the University enTwente Dutch SDR.  In doing research for this new Blog entry, it made sense to return
to that SDR during the EU evening/nighttime hours to discover which ones could be heard.

On the Asian end of things, while I frequently rely on the Eastern Asia beacons
("F" (Vladivostok), "M" (Magadan) and "K" (Kamchatsky)), frequently for whatever
reason, one or more of those beacons appear on the west coast to be AWOL.
To investigate that situation, a search was made to find web SDR in and around
Asia solely for the purpose of listening for this trio of beacons.

For some time, only the [relatively LOUD] "K" beacon could be heard in California. 
Recently, the "F" beacon could be weakly heard, altho the "M" seemed dormant. 
Having bookmarked over a dozen Asian-based web SDR sites, late in the morning
(evening in Asia) I cycled thru the SDR list noting which beacons were being heard
when / where at times when the bands should be open to those areas.

As it turns out, all 3 Asian beacons are active, altho the "F" and "M" beacons are clearly
running on reduced power (compared to past years) or there are antenna problems (or both). 
Being geographically closer to California, the "K" beacon is always reasonably LOUD. 
The fact that we have difficulty hearing "F" and "M" beacons may have less to do with lack
of propagation, then it does with the beacon installations themselves.

Tuning around, it was noticed that the "A" & "P" beacons seem to be off the air.  Near those frequencies an "I" beacon and "L" beacon were heard. The "I" beacon was very weak, while
the faster "L" beacon was relatively strong.  The PRIYOM.org website is where I first discovered
these beacons.  At this time. it would seem that the "I" and "L" beacons are not yet documented.

Now that the operational status of the Asian beacons have been [relatively] confirmed, attention
can be given to Europe - the missing "A" and "P" beacons and the arrival of the "I" & "L" beacons.
Then again while writing this Blog entry, listening one the 10.871 frequency, the "A" beacon was heard, albeit barely - very weak.

This brings us to a final conclusion.  While signal levels from each of the individual beacons are certainly affected by atmospheric propagation (the main reason we listen for them), remember that these beacons are what I call self-autonomous - a human being initiates their operation and then comes back every few years to check out the hardware.

With the Japanese JIDX Cw contest coming up on April 11th, closer attention/scrutiny will be given to the East Asian beacons ("K", "F" and "M").  Awhile back, with the assistance of the Gemini A-I facility, I unearthed the mysteries regarding the "DW" (Desert Whooper) beacon. 
([CLICK HERE] to read that.)

Whether we pay attention or not, the HF radio spectrum is LITTERED with propagation beacons
that we radio amateurs (especially radiosport contesters) can take advantage of.

Have YOU ever listened to the above mentioned propagation beacons?

What Discoveries have YOU made?

Creating an Audio Odyssey via Analog and Digital

It is no secret that I like to knob twiddle; adjusting controls enables me to maintain the illusion that

I can have some sort of influence over transmitted and received signals.  When it comes to received signals, there is always the desperate hope of being able to reduce/notch minute (but nonetheless annoying) bits of noise or carrier remnants.

Before owning my first radio w/some sort of DSP filtering (the classic Yaesu FT-1000mp), a JPS
NIR-12 external DSP unit was brought into my operating configurations for it and the ICOM 7000.
Later, because the FT-1000mp possesses only minimal filtering in the Sub-RX, inserting the NIR-12 into the R-channel audio line provides DNF (Digital Notch Filtering) and passband contouring for BOTH ears. Eventually, a JPS NIR-10 was cascaded into the right channel after the NIR-12.

Next up, a pair of MFJ-752 (Signal Enhancer II) units made the scene.  I inserted the 752-C into
the left channel audio.  For the right channel, a modified 752B was added.  The 752-B modification
was the addition of an old MFJ CW-1 filter board, providing 180 / 80 HZ Cw filtering.  

Even later, an MFJ-784 was picked up, offering even more knobs and buttons to play around with.
The MFJ-784 is unique in that the settings can be saved in a sort of local memory - a crude sort of
e-prom.

The REAL breakthrough came when I discovered the vintage Autek QF-1A analog filters. 
Front-ending it with a classic Radio Shaft 16-band stereo equalizer, shaping the desired passband BEFORE sending the audio to the QF1-A filters.  Cutting off the extraneous frequencies before/after
the desired receive passband reduces the possibility of harmonic overload.

Along the way, a passive mixer unit brings audio from the different radios into one input line,
splitting the audio amongst the various filter units.  The output of the units is then blended into
selectable audio using a classic Rockville 4-channel stereo mixer box.

As you can see, the above filter combinations offer a plethora of knobs to twiddle.

Do YOU make use of external audio filter units?

What Discoveries have YOU made?