Mystery Beacon 7508.75

[guthjain]

Heard a continual CW beacon on Twente 2310 UTC

SDHHDD SDHHDD SDHHDD

Speed: About 10wpm.
Signal: Excellent!

Not a clue. Anyone recognize this?

Thanks!

[Teotwaki]

It would help to have at least a rough idea of your location. In some areas that signal could be a fixed point to point service such as radio teletype so it would not really be a beacon. I cannot hear it where I am in California. At the moment I can hear the Russian beacon K on 7039.3 KHz so I have pretty good reception from that direction.

Jim
Orange County, CA

[guthjain]

It would help to have at least a rough idea of your location. In some areas that signal could be a fixed point to point service such as radio teletype so it would not really be a beacon. I cannot hear it where I am in California. At the moment I can hear the Russian beacon K on 7039.3 KHz so I have pretty good reception from that direction.

Jim
Orange County, CA

Jim, I was monitoring via the online SDR at the University of Twente, which is physically located in the Netherlands. Thanks for the read, though, mate!

G

[chucks]

2307Z 03/15/16

this beacon is now very audible and a nice trace showing up on the
sdr waterfall. now at 2330z it is fading away, just barely noticeable
on the waterfall and not audible at all.

never saw this one before but will have to keep an eye on it.

ChuckS

[Teotwaki]

Jim, I was monitoring via the online SDR at the University of Twente, which is physically located in the Netherlands. Thanks for the read, though, mate!

G

Thanks. Never heard of "Twente". It is rare that I will hear things directly from Europe. Russia has been fairly reliable over this way.

[Token]

The Russian single letter beacon D had moved up to that frequency.  Is it possible you are hearing it with a technical issue causing all those other letters?

T!

[Teotwaki]

That's a good point on mishearing a weak Morse D as a possible Morse letter S. i wonder how good of a receiver Twente is? I have observed the Russian beacons to be very accurate as to center frequency so it should be 7508.700 KHz if it is the beacon D.

[Teotwaki]

I just went to the University of Twente's web SDR and tuned in 7508.7 KHz on CW narrow and there was the Russian beacon D loud and clear. Next I tuned plus and minus 200KHz and you could still hear the CW letter D with the appropriate audio pitch from 7508.5 to 7508.9 KHz. A bandwidth that wide makes it hard to determine center frequency. What was interesting is that the waterfall display was not capturing the letter D keying properly. It showed quite a mishmash that looked like a CW letter S  then a D and other letters even though there was only a letter D in Morse being received.

Speaking of remote radios, I miss the one in the Mojave Desert 

[guthjain]

Well, it was quite clearly SDHHDD, but now it's a D

Perhaps some sort of malfunction with the sending software occurred? Dunno, but it went on for quite a while until I got bored watching it.
I wasn't the only chap to see it, but since it seems to be back to normal, it will have to be one of those little mysteries we all live with. Twente's SDR isn't perfect, but it's good enough to get most digital modes to copy properly, providing you fiddle a bit with things.

Thanks for the read, fellas!

G

[Teotwaki]

Heard a continual CW beacon on Twente 2310 UTC

SDHHDD SDHHDD SDHHDD

Just for clarification....

Did you listen to Twente's audio and actally hear SDHHDD or were you just looking at the waterfall?

When I listened last night I heard only a clear and slow letter D in Morse on the receiver audio even while the waterfall was showing all sorts of incorrect letters.

The other possibility is that the Russians since have a cluster of beacons and with Twente's overly wide bandwidth you might have heard some of the others at the same time. I will post my link to my audio from when I was in Fiji and had a similar experience hearing a few beacons at once on a receiver without narrow bandwidths.

7508.7 letter D
7508.8 letter P
7508.9 letter S
7509.0 letter C

There are more, just Google For Russian Cluster Beacons

Audio from the Fiji trip

https://m.youtube.com/watch?v=2Rgfys_ROOs

[Token]

The D beacon has had failures in the past and sent combinations of S, D, H, and N.  It is possible that is what was heard.

T!

[Teotwaki]

Are there any logs or recordings of previous CW oddities during transmission?