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Messages - SW-J

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Hearing Radio Pushka as of a few minutes ago - 6920 kHz AM mode 1400 UTC from Tejas area of US.

Also, Ch ina Woodpecker present most of the time now.

About 0940 UTC S9 signal and an easy copy this morning (3:40 am local time)

Can juuuuuuuuuuuuuuuuuuust tell there is something there ... below the local noise floor at the moment ...

1323z I've got audio! Can't make it out, but, program material is evident down south and out west here ...

North American Shortwave Pirate / Re: 6936.66 usb Red Merucry
« on: November 02, 2013, 0320 UTC »
0319z S7 average, peaks to S8 ... had trouble tuning them in just going by 'sound' ... showing 6936.64 kHz here ...
0326z Good signal RML! S5 1/2 to S7
0346z S7 ATTM and easily copyable RML ...

North American Shortwave Pirate / Re: XFM 6950 KHz AM 0027+ UTC
« on: November 02, 2013, 0043 UTC »
... with the power of a broadcaster and the smooth voice of a seasoned host, X-FM is sounding GREAT tonight!

0043z S9+5 dB
0106z still holding nominally at S9+5 dB mon ami. Tnx for the show!
0123z band is not being so kind now, a little more QRN kicking up and average sig strength S8 but still a good copy!
0127z back to S9+5 dB!
0141z 2nd wind kicking in! Sig strength S9 up to S9+5 dB at times!
0151z Blasting in with peaks at S9+10 dB and constant at +5 dB now! Linda Ronstadt and "He's a magic man"
0213z bass notes CLEARLY come thru better on AM ... X-FM shows this time and time again .... S9 to S9+5 dB mon ami
0237z "Radar Love" never sounded so good! S9+5 dB ... Great sig X-FM!
0245z "When the Bullet hits the Bone" S9 +5 ... still GOOD copy!
0248z An annoying carrier came up about 500 Hz or so above the X-FM carrier (above in frequency, that is) ... now sounds like another station in there w/audio? Now it seems to be gone by 0251z ... Note: X-FM carrier is about 30 Hz high in frequency so this is a good way to verify who is who!
0303z "I'm on Mexican Radio" sig in the S9 to S9+5 dB
0315z And off? (stepped away and did not hear sign-off! Oops ... my bad)
0336z Thank goodness for bandscopes or would have missed this: X-FM rolling back in here after a significant band fade for a bit!
0344z S9 sig level ATTM but fades are becoming longer and more pronounced ...
0349z Genesis and showing S9+5 dB ...
0402z "Urgent" at just over S9 sig level ...
0424z ... into some electronic 'genre' music now ... this should be interesting on SW! Op also mentioned he's beginning to put the 'brakes' on the show now ...
0437z Shout-out to board members posting in this thread (Tnx X-FM) and a good evening to everyone.
0440z S9+5 dB and steady signal on final song ...
0444z Off and clear! Carrier gone ... the frequency is clear. Thanks X-FM!

Great show X-FM!

« on: November 01, 2013, 1354 UTC »
hearing P on 29882.72 Khz 1835 UTC
Is this a ham beacon

Not a US ham, at least. In the US "10 Meter band" is allocated as 28.000 - 29.700 MHz

Per: http://www.arrl.org/frequency-allocations

Manufacturing of computers, phones, tablets and other devices was contracted out to China, arguably the world's #1 source of government sponsored hacking.  What did they think might happen?  Vulnerabilities and exploits are being hard-wired into devices, and not just due to pressure from the NSA.

"Then, when Ruiu removed the internal speaker and microphone connected to the airgapped machine, the packets suddenly stopped.

"With the speakers and mic intact, Ruiu said, the isolated computer seemed to be using the high-frequency connection to maintain the integrity of the badBIOS infection as he worked to dismantle software components the malware relied on."

--arstechnica, 10/31/13

Story is lacking in facts; the man should have had a copy of Wireshark running on another machine and capturing packets. esp destination IP addys ... just sayin.

The 'security consultant' had a chance to thoroughly characterize the little beast (and perhaps even reverse engineer it and _confirm_ his observations), but, lacked either the time or skill set to do so ...
Summary observation: A 'UFO report'.

... hear singing child's voices? at 0359z ...

0402z ... can hear a kid's voice singing ... very weak signal here ...
0416z .. signal level is coming up some ... sound effects/'scary' sounding music playing ...

North American Shortwave Pirate / Re: UNID 6935 AM 0318z Sept 1, 2013
« on: November 01, 2013, 0321 UTC »
0321z Clearly hearing pgm material/music now ... op's voice ... can't make out ..
0324z ... a little more audio come thru ... there may be two stations in there now ...
0336z Copying "Who ya gonna call - Ghost Busters" song  

.. should say, listening on USB since there is strong CW still going on LSB ...

0339z "The Monster Mash ... it was a graveyard smash" song

Andrew, I heard a 'bubbling' sound in there btw Ghost Busters and Monster Mash ... is that a Liquid Radio trademark?

0349z Carrier just 'dropped' on 6935 ... a min or so prior to that heard an op speaking ...

0314z ... coming up in signal strength last 5 to 10 mins ... also, the 'mode' appears to be 6920 USB (PS there is no carrier) rather than AM at the moment ...

0315z peaks to S4 (it is quiet on the band tonight!)
0326z station appears to be off ...


0301z Freq a little closer to 6950.05 KHz ... (at the time of this posting!)

North American Shortwave Pirate / Re: X-FM 6870 KHz AM 0355z 11-1-2013
« on: November 01, 2013, 0231 UTC »
... IMO an under-rated pirate with really good sound!

S9+10 dB ... really easy, arm-chair copy (a few fades --this is SW after all!-- here and there)

0250z Shout-outs to posters on the board ... Tnx X!

0257z last ID and out, off and clear!

Thanks for the program X-FM! It was delightful and varied!

Utility / Re: Wideband, High-Pulse Radar
« on: October 15, 2013, 1632 UTC »
This signal is one I have been watching since late 2011, in my log it is called “Big Tones”.  Originally it started with 1 kHz tones (pulse repetition rate), and has also used that pulse spacing recently, but most often it uses the 300 Hz as you have shown here.

I cannot tell you what it is (I simply do not know, although I have a few rough guesses) but I can tell you what it is not.  It is almost certainly not a radar, and it is almost as certainly not a sounder.

So, why not a radar?

With any radar you can tell certain potential performance parameters based on the transmitted signal.  This does not give you the complete picture of its capabilities, but it does define a few boundaries of performance.  Depending on the radar type (pulse, FMCW, pulse Doppler, etc) you can tell different things from its transmissions.

With a simple pulse transmission like this one (there does not appear to be any modulation on the pulses that are significant for radar applications) three parameters are very easy to determine.  Maximum possible unambiguous range and minimum range resolution.  Maximum unambiguous range is simply the maximum range at which the radar can detect a target and be sure of the range.  Minimum range resolution is the minimum distance between two targets that is possible and the radar still be able determine that there are two targets there, not just see the two (or more) as a single target.  The same factors that determine minimum range resolution also determine minimum possible detection range, the closest target that can be seen.

Maximum unambiguous range is determined with the formula R = (c x t) / 2.  R is the max range, c is the speed of light, and t is the radar PRI (pulse repetition interval, time between pulses, leading edge to leading edge).  The speed of light and the time need to be in the same time unit, normally seconds.  Whatever distance unit is used for c will determine the distance unit for R.

We will call c = 300000 km/sec.  The PRI for this signal is 3.333 msec, or 0.003333 seconds (this is 300 Hz, as in your example, but I have seen it as high as 303 Hz).

(300000 x 0.003333) / 2 = 499.95 km

So the maximum unambiguous range is 500 km.  OK, this seems a reasonable max usable range for a radar, even if a bit short by some OTHR standards.

Minimum range resolution is determined using the formula Rr = (c x PW) / 2.  Looks familiar, ah?  Radar is very time dependant, and radar wave travel at the speed of light after all.  Rr is the minimum distance apart two targets can be and be detectable as individual targets.  c is as defined above in the maximum range formula.  PW is the pulse width.

The pulse for this signal is 900 microseconds, or 0.0009 seconds (I have seen shorter pulses also, down around 835 microseconds).

(300000 x 0.0009) / 2 = 135 km.

(edit) I originally failed to mention that Pulse Width also determines the minimum range at which a simple pulsed monostatic radar can be used.  It cannot listen while the pulse is being transmitted, and so during this pulse transmission time, and for some recovery time after the pulse ends, the radar is “blind”.  Since time is distance then the minimum range a radar using the above pulse width can see would be a bit over 270 km.

So, if this signal were a radar it would have a maximum usable range of 500 km, a minimum usable range of 270+ km, but it would not be able to tell two targets apart unless they were over 135 km apart.  Basically it would end up with less than 2 usable range cells in its full range.  This means that if there were 2 targets in its illumination cell that were each 130 km from the other then it would see one large target from min range to max range.

Not a very affective design ;)  And the 1 kHz version of the signal is even more limited, since it uses a 50% duty cycle (square wave).  So, in my opinion and based on a few years in the field of radar, almost certainly not a radar.  There are also a couple of other modulations seen on the signal, such as a 4.5 kHz sine wave of low modulation depth.

I have been seeing this signal since late 2011.  It uses several frequencies, and seems to hit them pretty dependably / repeatedly.  It generally starts at the lowest freq and then moves up as time goes on, but it frequently goes back and revisits

Some of the frequencies seen (not a complete list, but the most common ones I have seen, each used at least 3 times on separate dates in my logs):


Video of the signal on 6970 in 2012 (PRF and PW slightly different from your example, but the same signal):

Picture of the spectrum (if you have no other way to detect the pulse width the reciprocal of the time from peak to first null will yield the PW, or half the frequency from first null on low freq side to first null on high freq side):

Hope some of this helps.


Good post, and applicable for 'search' modes, but, overlooks ISAR (Inverse synthetic aperture radar) techniques, which allow finer detail to be observed/resolved on targets once something has been detected; by saturating a target with a series of pulses a 'profile' of the target can be detected by observing the minute Doppler shifts imparted on the reflected RF energy ... also using multiple frequencies (in combination with ionospheric sounder data) allows improved target location, allowing some of the vagaries of HF propagation to be 'nulled' out.

0321z Signal peaks at S7 in Tejas now ... as the show starts ... ... acknowledges the govt shutdown ... and the 'Friendly Candy Company' and all ...
0330z Good lows Renegade! Signal about S6 with fading.
0339z Shoutouts to HFU and general commentary ... stands on 'the shoulders of Wolverine Radio' following him on this frequency ... thanks for the pgm Renegade!

0233z Good sig S7 with a lot of selective fading; Good evening RML!

0124z S9 signal! Wow!
0127z ID as Wolverine Radio still a great signal and pgm too!
0139z S9+10 dB easily ... tnx for the program Wolverine!
0205z S9+10 dB peaks ... tnx Wolverine!
0218z Copied ID ... S7 to S9 now, still an easy copy ... tnx Wolverine!
0228z Copied "Wolverine Radio" ID ... sig good S7 to S9 now with selective fading evident. Tnx 4 pgm Wolv!
0300z Copied last ID (w/echo!) followed by SSTV image. Thanks for the show Wolverine!

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