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Author Topic: Link-11 6944-6950 kHz  (Read 6232 times)

Offline ChrisSmolinski

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Link-11 6944-6950 kHz
« on: April 02, 2012, 1636 UTC »
I've been noting Link-11 transmissions in this range 24 hours a day, for the last few days. I mentioned this in an earlier blog post: http://www.hfunderpants.com/?p=787

This is a US military data system. Since it can be heard 24 hours a day, that implies that they are somewhere close by. If they can be heard here, then pirates transmitting on 6950 or even 6955 could be heard by the people operating these transmissions, and could possibly cause interference to them, annoying the users.

Hint Hint.
Chris Smolinski
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Offline zackers

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Re: Link-11 6944-6950 kHz
« Reply #1 on: April 02, 2012, 1743 UTC »
Well, I guess it's good to have another name for this type of transmission besides "The Chicken"! I've been hearing it for decades on various frequencies.
East Central Illinois
TS-850S, 40 meter full-wave loop, various dipoles

rdla4

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Re: Link-11 6944-6950 kHz
« Reply #2 on: April 02, 2012, 1928 UTC »
Also audible all day/all night in North Georgia. 1926, on 4/2 its is running an easy S8, depending on the frequency you tune in too between 6945 and 6950. I will see if I can get my loop out in the backyard and see if I can get a rough bearing for this one.

It loops out as being roughly 45 degrees TN from the Acworth/Atlanta area. Loops can give erroneous readings with skywave so YMMV. 2339UTC
« Last Edit: April 02, 2012, 2329 UTC by rdla4 »

Offline ChrisSmolinski

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Re: Link-11 6944-6950 kHz
« Reply #3 on: April 02, 2012, 2148 UTC »
With a few more signal reports from listeners (ideally at around the same time) we may be able to pin down about where these transmissions originate.

Chris Smolinski
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Offline zackers

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Re: Link-11 6944-6950 kHz
« Reply #4 on: April 02, 2012, 2236 UTC »
It's running about S7 here now, a couple hours before sunset. Some QSB, dips down to maybe S3 and back. No DX heard on 40 meters now. So it has to be not too far away.
East Central Illinois
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Offline jFarley

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Re: Link-11 6944-6950 kHz
« Reply #5 on: April 02, 2012, 2237 UTC »
2235 in Chicago; abt S3 and no where near the strength I've been seeing it at night.
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Offline zackers

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Re: Link-11 6944-6950 kHz
« Reply #6 on: April 02, 2012, 2240 UTC »
Interesting it seems to be louder here than in Chicago. I'm only 150 miles to the south.

It seems to be running some sort of an idling loop now. Repeating a "dit dit dit dididididit dah" pattern over and over.
« Last Edit: April 02, 2012, 2242 UTC by zackers »
East Central Illinois
TS-850S, 40 meter full-wave loop, various dipoles

Offline ChrisSmolinski

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Re: Link-11 6944-6950 kHz
« Reply #7 on: April 02, 2012, 2249 UTC »
Some more datapoints:

Someone to the south of me near DC had it at S8

Northern Florida less than S1

S7 in Northern KY

If we can get some daytime reports to the north east (New England area) it might help. I'd like to see what the NVIS coverage area is.
« Last Edit: April 02, 2012, 2304 UTC by ChrisSmolinski »
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline Zoidberg

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Re: Link-11 6944-6950 kHz
« Reply #8 on: April 03, 2012, 0030 UTC »
Yup, TADIL has been very intrusive lately, hard to listen to nearby broadcasts without some noise reduction.  Interestingly my old Radio Shack DSP noise reduction doodad is pretty effective at muting this type of tone.  I can still hear it, but it's attenuated enough to be less irritating, while the adjacent pirate broadcasts are still audible.
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Offline corq

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Re: Link-11 6944-6950 kHz
« Reply #9 on: April 03, 2012, 0107 UTC »
oh just because, well ... FOR SCIENCE

http://corqswl.posterous.com/6946u-link-11-swl
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Offline L Cee

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Re: Link-11 6944-6950 kHz
« Reply #10 on: April 03, 2012, 0122 UTC »
s8-s9 here. My guess would be USN in Southern MD/VA ?
L Cee
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Offline Sealord

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Re: Link-11 6944-6950 kHz
« Reply #11 on: April 03, 2012, 1026 UTC »
6947.460 USB SIO 434

Hammering away into the swamplands - when I first checked the frequency before 10:00z it was just idling.

10:18z-10:19z Link-11

Audio: http://archive.org/download/ShortwaveOddsSodsTransmissions/Link-11DataTx6947_460Usb1018z-1019z04-03-12.mp3
« Last Edit: April 03, 2012, 1532 UTC by Sealord »
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rdla4

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Re: Link-11 6944-6950 kHz
« Reply #12 on: April 03, 2012, 1247 UTC »
Nearly as strong day and night in GA. 1244UTC, its running S9 in GA.

Also, at 1245, it seemed to stop transmitting-----at least for a few minutes.

1249, Still silent. Along with a few others, this appears (from loop bearings) to be in the mid-Atlantic somewhere.  Bearing from here was 45 degrees (and its opposite bearing). 45 deg takes in a huge chunk of land, including The D. C. Area,
« Last Edit: April 03, 2012, 1253 UTC by rdla4 »

Offline ChrisSmolinski

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Re: Link-11 6944-6950 kHz
« Reply #13 on: April 03, 2012, 1527 UTC »
s8-s9 here. My guess would be USN in Southern MD/VA ?

Yes, I was thinking perhaps the Hampton Roads area.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline zackers

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Re: Link-11 6944-6950 kHz
« Reply #14 on: April 04, 2012, 1334 UTC »
Last night (about 0400Z March 4) I listened for a half hour or so and heard nothing. This morning (1300Z) for a half hour I hear nothing. Maybe it's gone for now or found a different frequency to use?
East Central Illinois
TS-850S, 40 meter full-wave loop, various dipoles

 

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