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Messages - AlanC

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HF Beacons / Re: 6780 kHz CW beacon
« on: September 23, 2019, 1948 UTC »
Still going Sept. 2019, weakly audible in the UK. Has twenty 100mS pips at 1 second intervals, the last pip being about a second long. Then 2 sec silence before the sequence repeats. Sometimes the sequence is shorter than the 20 mentioned above. Has quite soft keying.

HF Beacons / 6780 kHz CW
« on: March 03, 2019, 2244 UTC »
I'm listening on the Twente WebSDR to a CW transmission on 6780kHz that consists of a number of 1 second dits followed by a longer dah, then approx 3 seconds of silence before the sequence repeats. The number of dits in each cycle is generally 19 but occasionally it is much less. Also the long dahs can vary in length.

I'm assuming its some pirate beacon??

73, Alan in Sheffield UK.

Here's a round-up of what was audible over the past hour or so from Sheffield, UK. My RX setup is RTL-SDR dongle on a Raspberry Pi running as a RTL-TCP server, then SDR Sharp running on a Win 7 laptop. Antenna is a home brew 3-element yagi cut for 250MHz bearing 220 degrees azimuth and 30 degrees elevation. This is quite a potent set up- the pirates are mostly fully quieting signals. NB that the transponder bandwidths given are approximate.

Transponder outputs are easily seen by the lift in the noise by up to about 10-15dB over the receiver noise floor.

I am amazed how much pirate activity there is.

243.8 - 243.85 looks like 'Raindrops' some kind of frequency hopping system

244.075 8 transponders with about 4 kHz bandwidth. No visible activity.

244.185-   5 transponders with 3.5kHz bandwidth.
244.200 has narrow band data bursts, 2.5 sec every 7 sec
244.205 missing

245.200 25khz wide transponder, with FM voice pirates active

249.105 13 transponders of 4kHz bandwidth, many with data bursts

249.450 25khz wide transponder, with FM voice pirates active
249.575 25kHz wide transponder, 'sloping top'. wideband data bursts
251.325 25khz wide trasnponder, 'dome top'
251.700 25khz wide trasnponder, 'dome top'
251.950 25kHz wide transponder, flat top. wide band data bursts
252.050 25kHz wide transponder. FM Voice pirates active near the HF edge, narrow band data bursts near the LF edge.
252.150 25kHz wide transponder.
253.750 25khz wide transponder, with FM voice pirates active
253.850 25kHz wide transponder.
253.900 25kHz wide transponder with some very interesting signals;
1. at the LF end, beginning at 253.886180 are 11 tones on 170Hz spacing sounding very like the old VFT; no TTY visible though
2. Centered on 253.913.0, some odd signals that could be data of some sort or could be analogue speech encryption, listen on SSB mode...
3. In the centre, is en-clair US OM voice in AM mode sounding like Air Traffic Control (mention flight levels etc). Yesterday was much more active with almost continuous transmissions. Weak signal and due to QRM just to the HF side of the carrier I needed to use LSB to hear it best. 10.51 UTC Now Telling A/C to contact New York on [just unreadable] frequency

254.155 25kHz wide transponder. wide and narrow band data bursts in the centre, narrow band data signals near HF and LF edges.
255.450 25kHz wide transponder. FM Voice pirates active at both .440 and.460 - first time I've seen 2 pirate QSO's on same transponder!
255.550 25kHz wide transponder. with FM voice pirates active as always!
257.050 25kHz wide transponder with wideband data bursts and with FM voice pirates active near HF edge
257.150 25kHz wide transponder with wideband data bursts
257.500 30kHz wide transponder
258.550 30khz wide transponder
258.650 25kHz wide transponder
260.425 25kHz wide transponder with wideband data bursts and with FM voice pirates active a little LF of centre
260.525 25kHz wide transponder with wideband data bursts and with FM voice pirates ?Japanese? active a little HF of centre
261.280 25kHz wide transponder with data and what sounds like QRM on the input from wideband FM music station chopping in and out

261.875 25kHz wide transponder with wideband data bursts
262.075 30kHz wide transponder
262.100 5kHz wide transponder
262.150 5kHz wide transponder
262.175 30kHz wide transponder
262.200 5kHz wide transponder
262.275 30kHz wide transponder
262.375 30kHz wide transponder
263.725 30kHz wide transponder with wideband data bursts
265.350 25kHz wide transponder
265.450 25kHz wide transponder with wideband data bursts and with FM voice pirates active


Utility / Re: Air Horn and Buzzer both poorly...
« on: July 20, 2017, 1042 UTC »
Sheffield, UK but I was listening on the Twente webSDR.

Utility / Air Horn and Buzzer both poorly...
« on: July 16, 2017, 2124 UTC »
The 'Air-Horn' on 4020 is not radiating it's normal signal; there is plenty of carrier but the modulation is a weak 'prrrr-prrrr-prrrr' instead of the normal strident tone. Sounds 50Hz-ish.

Coincidentally the buzzer on 4625 is almost completely off air- it was very weak earlier and now it's almost completely gone, no carrier just a bit of sidebands. I'm struggling to believe its just bad propagation, I've never heard it that bad before and everything else seems normal.

Utility / 11175 very busy
« on: June 10, 2017, 1532 UTC »
11175 seems very busy again today, with DYNATRON sending many messages to ALL STATIONS prefixed FOUR-POSTURE and FOUR-RAZORBLADE.

Utility / Re: Carrier pulse on 13.560
« on: May 17, 2017, 1854 UTC »
13560kHz is the frequency used by many RFID devices and also Near Field Communications (NFC). It's possible that what you're hearing is an access control swipe card reader or a contactless card payment machine somewhere, or possibly just a mobile phone with the NFC turned on. These devices radiate quite a long way.

Loads of info here:



Utility / Letter Beacon D 5292kHz
« on: February 14, 2017, 2323 UTC »
Channel marker D on 5292kHz; the keying is odd- the 'dah' is shorter than usual. The transmission is SSB with the carrier partially suppressed and the modulation is a keyed 1kHz tone which has a lot of second harmonic i.e at 2 kHz as well. Actually it has a lot in common with 'the pip'. This is not the D beacon we hear in the cluster beacons, whose keying is generally more accurate in timing and has a much cleaner transmission.

Utility / Re: HF logs - December 2016
« on: January 02, 2017, 0938 UTC »

There's a lot of very interesting stuff in there!

Nice work.

Happy New Year

Utility / Re: Voice tests on 4742kHz
« on: January 02, 2017, 0931 UTC »
Thanks for your reply and I can confirm that.

Back in the good old days of STCICS you'd hear Architect with weather reports on the hour and airfield colour states on the half hour, and at other times aircraft on long distance flights (C130 Herc's with the callsign ASCOT and four digits). General calls were made to the callsign CELEBRITY e.g. "Celebrity celebrity this is Architect Architect. Airfield colour states at zero nine zero zero zulu....".

When it all changed to TASCOMM in the middle of 2006, Architect fell silent and to my knowledge has never been heard since, unless you or anyone else knows different? I was fairly sure HF had been pretty much abandoned, however the test transmission I heard shows that the infrastructure is still there at least and I that is quite significant.

Some monitors have reported hearing ALE bursts with callsign XSS (Forest Moor NCS) but not regular soundings as you hear on the DHFCS ALE net.

Happy New year

Utility / Voice tests on 4742kHz
« on: December 30, 2016, 1926 UTC »
Heard 'This is TASCOMM test test 1 2 3 4 5' and off; OM with UK accent once at about 18:55 and again at 19:00 on 4742kHz USB today (30th December 2016)


Utility / Re: XM 5040 khz
« on: December 13, 2016, 1207 UTC »
Hi linkz

That's really interesting, I'll wait until R Habana is on and have a listen. You're right they aren't enigma stuff.

To answer your question MDK2, I'm usually listening UK day or evenings so outside those hours :)


Utility / XM 5040 khz
« on: December 09, 2016, 0820 UTC »
Strange unearthly feedback noise been there on this freq every day this week! 5040khz USB.

Utility / Re: HF logs - November 2016
« on: December 07, 2016, 1100 UTC »
Thank you :) lots of interesting ones in there!

Utility / 5032kHz Mil? Net
« on: December 07, 2016, 0947 UTC »
09:30 7/12/2016 but ongoing; USB net with stations exchanging coded messages in English, ops have German accent. Op procedure sounds very military. Heard via Twente SDR, gud sigs.
Bravo Quebec Oscar 4
Delta Hotel Juliet 5 8
Zulu Echo Charlie 3
Delta Hotel Romeo Juliet
Juliet Romeo 9 Yankee

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