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Topics - AlanC

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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 / 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 / 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 / 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 / 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 / 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

Utility / XLA/XLB ALE who are they?
« on: November 18, 2016, 1259 UTC »
Anyone know who these are?

XLA and XLB net
5106.2, 5210.2, 6393.0, 7505.7 ALE USB

Every 2-3 minutes on each frequency yesterday 17th November 2016, always XLB calling XLA:

[2016-11-17 20:07:03] [NORMAL MODE][TO][XLA][TO][XLA][EOM]
[2016-11-17 20:07:04]
[2016-11-17 20:07:04] [NORMAL MODE][TO][XLA][EOM]
[2016-11-17 20:07:05]
[2016-11-17 20:07:05] [NORMAL MODE][TO][XLA][EOM]
[2016-11-17 20:07:05]
[2016-11-17 20:07:05] [NORMAL MODE][TO][XLA][TO][XLA][EOM]
[2016-11-17 20:07:07]

Suddenly went QRT at 22:00 utc.


Utility / 10410 khz ALE
« on: December 14, 2015, 0947 UTC »
I'm hearing Forest Moor XSS sounding every 30 mins (approx 27 and 57 minutes past the hour) on 10140khz, which I don't see listed as a DHFCS frequency... no other stations heard... is this part of a known net?

73 Alan

HF Beacons / L beacon 6917: power supply smoothing failed!
« on: November 17, 2014, 1840 UTC »
The L beacon on 6917.5 is a good signal at the moment, but it is modulated by a raucous 100Hz hum, resulting in the signal being spread over several kHz.

HF Beacons / F is back to L again
« on: October 13, 2014, 2221 UTC »
Seems to confirm the short duration or special event status of the F (or C-F-F-F-F-F as it was) operation.

HF Beacons / F beacon on 8498
« on: October 11, 2014, 2214 UTC »
This frequency is where you usually find the 'L' beacon, today however it is sending F's- only every 6th 'F' is a 'C'! This beacon has a long history of being quirky- up until about 10 years ago it was chirpy and sometimes had the odd dit missing- as if a mechanical keyer was used that had bad contacts. Then it seemed to get an overhaul and behaved itself for a bit. Actual carrier frequency is about 8498.55

Other / 11354 kHz- hummy SSB transmission
« on: October 10, 2014, 1507 UTC »
On 11354 kHz 14:59 UTC today there is what sounds like a USB transmitter connected to a bad landline- it's sending continuous harmonicy hum; S3 or so with much QSB. Can't tell if the hum is 50 0r 60 Hz based. Can hear HFDL packets from Riverhead, NY through it so it's not that Tx!

HF Beacons / 'V' beacon 6928
« on: October 09, 2014, 2131 UTC »
'V' channel marker (letter) beacon on 6928kHz with its characteristically slightly short dash... Good copy now 22.30 9/10/2014, peaking at S7-8

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