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Author Topic: Widespread "sizzling" interference on 75 meters this evening  (Read 18253 times)
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W1AEX
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« on: April 17, 2011, 07:55:24 PM »

I was tuning around the 75 meter band this evening at around 6:30 PM and began to notice that the background noise was steadily rising. At first it was just a trace of sizzling up and down the band, but by 7:00 PM it had built up to the point where it was covering weak signals. Oddly, I was also hearing it just as well with my NS and EW receive loops that are located away from the house. Normally, they're pretty much immune to local noise.

At any rate, I tuned across an AM QSO on 3880 and heard Al W1VTP asking if anyone else was hearing a sizzling noise on the band. The other stations (Terry W2PFY, Tom N1HCI, Tim WA1HLR, and Brent W1IA) all confirmed that they were hearing it quite loudly as well. The video at the link below is a 2 minute sample of what we were hearing. Is this a Northeast phenomenon or has it been heard elsewhere? Is this some variation of the H.A.R.P. noise as Tom N1HCI mentioned? Last winter a group of us encountered the same thing on 160 meters, and if my memory hasn't failed me, it sounded exactly like what is heard in the video. Anyone have a clue as to what this might be?

http://www.youtube.com/watch?v=U6id7WumpBE
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« Reply #1 on: April 17, 2011, 08:50:34 PM »

I was on with Brent earlier when it first started. I was listening on 40 around 1:30 and also heard it there.
Maybe it is just spring conditions... raining here now at 8:30.
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KC2UFU
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« Reply #2 on: April 17, 2011, 09:04:46 PM »

Well Rob, interestingly enough, right around that time Ken and Garrett were outside testing a jacob's ladder they built.  Coincidence?  I think not! LOL Shocked
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Steve - K4HX
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« Reply #3 on: April 17, 2011, 09:09:17 PM »

I did not hear it. Just the remaining static from last night's storms.
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flintstone mop
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« Reply #4 on: April 17, 2011, 09:19:45 PM »

I have heard that also in the past. Might be from the widespread winds over large geographical areas. Then it goes away.
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Fred KC4MOP
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« Reply #5 on: April 17, 2011, 09:28:05 PM »

I also heard it here in CT at the time your recording was made, Rob.

Interesting that Brent said the solar activity was quiet at the time and Frank said it was on 40M too.   I have heard weaker noise like this when beaming west during sunset, but never heard noise this coarse-sounding and loud as reported over such a wide area.   It is usually local.

My guess is it was natural and not man made.  I should have tried switching directions but didn't think of it.

T

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« Reply #6 on: April 17, 2011, 09:55:18 PM »

Gee I didn't think to try the directional RX ants. The band was pretty quiet around 3:30 for the pw net. I heard Al VTP running 1/2 watt. We had some rain go through here a while ago. WX is funky with all the things going through last day or so. It could have been a couple air masses duking it out over the ocean.
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« Reply #7 on: April 17, 2011, 10:09:14 PM »

It's a curious phenomenon that I don't recall hearing before last winter. The sound does seem to mimic snow static, but whatever this is, it seems to be propagating pretty well. I heard the same noise while listening on 40 meters several weeks ago and another time while in a QSO on 160 meters, where all the other stations (NY, NJ and CT) heard it as well. With Steve not hearing it down in VA that sort of narrows it down to the northeast for now. Fortunately, it doesn't seem to happen too often!

Fred might be correct. It could just be high altitude winds charging the atmosphere with resulting widespread discharges. Or as Frank said, it could be colliding fronts out in the Atlantic. The latest geophysical report from NOAA agrees with Brent that it's all quiet "out there".

Then again, if Kerry could just keep that man of hers away from the Jacob's Ladder, maybe this kind of strange stuff would stop happening!


* geophysical report.jpg (26.15 KB, 518x264 - viewed 396 times.)
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« Reply #8 on: April 17, 2011, 10:44:02 PM »

operated 7290 this afternoon.  worked steve KJ8CQ and Budley.  no noise oh, just saw that this was on 75.  oops.

I guess there are advantages to townie high noise level, hash and buzzies and a bad antenna.  I can't hear any sizzling.

40 was pretty good this afternoon.  had qsos with pw 50 watts.
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Ralph W3GL
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« Reply #9 on: April 17, 2011, 11:00:14 PM »

    I heard it and commented on it during the "What Fudds Do" net this evening
    just before the Disruptor showed up.  He should have heard it at his location.

    At the time, checking the lightning map on here, that system that created
    all the damage yesterday and last night/this morning was still going strong
    several hundred miles off the coast in a line from the top of  FL to above ME.
    Me thinks it was propagating back this way as the sky wave absorption de-
    creased.   Same noise that you can hear during twister conditions, etc...

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« Reply #10 on: April 17, 2011, 11:13:13 PM »

The only noise I heard was you Ralph.   Wink
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« Reply #11 on: April 18, 2011, 04:13:35 AM »

  I was on with Brent a bit before the recording when it came up and he lost my signal in it. His signal dropped also by at least 10db on my end. The noise had a clear cyclic sound like the last groove of a very dirty record. It seemed to fade out then came back again about the time of the recording which I heard live at pretty much the same levels.
 Funny, it did sound like a tesla discharge.
   
  Interesting.

Bill
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« Reply #12 on: April 18, 2011, 01:34:46 PM »

I really thought it was my Hammarlund receiver acting up until I heard this recording.  It was way louder over here to the point where I had to turn the receiver down. Glad to know it isn't my receiver. At the time when it was loudest, a cloud cover blocked out the sun. 

Thanks for the recording. Looks like I need more highs Grin Grin
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« Reply #13 on: April 18, 2011, 11:35:11 PM »

   I heard it and commented on it during the "What Fudds Do" net this evening
    just before the Disruptor showed up.  He should have heard it at his location.

    At the time, checking the lightning map on here, that system that created
    all the damage yesterday and last night/this morning was still going strong
    several hundred miles off the coast in a line from the top of  FL to above ME.
    Me thinks it was propagating back this way as the sky wave absorption de-
    creased.   Same noise that you can hear during twister conditions, etc...



A Romulan Disruptor? haha maybe he's a Klingon.

I couldn't find this "What Fudds Do" net listed. How about it, I'd like to listen in.
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« Reply #14 on: April 19, 2011, 10:51:15 AM »

3733 khz 5 PM or so Eastern time.  Doubtful there's propagation to you that early, Patrick, most of the guys are in the MD/PA/DE area.
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« Reply #15 on: April 19, 2011, 11:52:02 AM »

I heard the Bacon Effect (not to be confused with the Bacon Beacon) last night on 80m. First time here. It really does have a sizzling frying pan sound to it. Also something that sounds like a 500 lb bumble bee buzzing past the frequency at a high rate of speed, several times. Wonder if it's some kind of spread spectrum stuff.

Listened for the What Fudds Do net last night, but no one was on. I must've been early.  Grin

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« Reply #16 on: April 19, 2011, 12:51:11 PM »

I heard the Bacon Effect (not to be confused with the Bacon Beacon) last night on 80m. 

Todd,

Frying bacon is a good name for it... :-)    I heard a bit of it yesterday too, but only a short blast. If it persists, then maybe we should start considering spread spectrum sources.

Quote
Listened for the What Fudds Do net last night, but no one was on. I must've been early.  Grin

What Fudds do? You answered your own question.

T
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« Reply #17 on: April 19, 2011, 01:15:10 PM »

   Naraganset Bay........
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« Reply #18 on: April 19, 2011, 02:20:41 PM »

Maybe they converted the HF radars to spread spectrum.    This is a very simple conversion for coherent Doppler radars.
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« Reply #19 on: April 19, 2011, 05:49:41 PM »

...Also something that sounds like a 500 lb bumble bee buzzing past the frequency at a high rate of speed, several times. Wonder if it's some kind of spread spectrum stuff.

Todd, that's a great description of the frequency agile buzz that frequently rolls up through the HF spectrum. I often hear guys referring to the buzz as H.A.R.P. transmissions, however, I was informed that it's a different project. Someone from YouTube (...yah, I know, if it's on the internet it MUST be true...) referred me to the link below that describes the Ionospheric Sounding project, which is a more likely candidate for the 500 lb bumble bee. It's a very long technical description, but these three sentences jumped out at me:

"...measurements require scanning of the entire propagating band of frequencies in the 0.5 to 20 MHz RF band"

"The frequency range of 1 to 20 MHz for vertical sounding was an accepted standard, and 2 to 30 MHz was accepted as a reasonable range for oblique incidence measurements. "

"A required power level in the 5 to 10 kW range for pulse transmitters had provided good results in the past."

http://ulcar.uml.edu/DPS.htm

Maybe someone here knows what's going on with that. So far, no one has indicated anything man-made that might be responsible for the sizzle in our lives.

Rob W1AEX

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« Reply #20 on: April 20, 2011, 10:13:36 AM »

The "5 to 10 Kw" peak power in the past would average out to a few hundred watts average power.  Now with phase encoding you actually only need the 300W of power, transmitting long pulses but dividing the pulse up with a known sequence of phase shifts.   The receiver "knows" the code and decorrelates the long pulse into much shorter pulses of information.  Externally to other receivers it looks and will sound like noise over a finite bandwidth.  The coherent integration is a receiving technique in Doppler radar.   The Doppler radar receiver operates the same as an SDR receiver.  Processing is done on the I an Q channels.    If the I and Q signals are filtered or integrated before processing, it provides a noise reduction greater than if the filtering was done after detection.   The trade off is that it lowers the spectral bandwidth of the processed information.
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« Reply #21 on: April 20, 2011, 11:58:21 AM »

I did some more band listening and thinking over the weekend about this.

Yesterday I observed that after conversion to the solar barycenter Irbonium time frame, this Bacon Frying effect shows two-way pulses providing range data. Taylor shifted received signals used as inputs to the special relativistic "Bacon" expression determine the measured pulse velocity. Huzium gravitational models that predict the degree of slowing over time are very precise, and provide the expected velocity for any time period or range, given the Bacon’s trajectory history. When the observed Derbium Taylor shift is compared to the expected value from gravitational modeling, there is a constant residual offset that correlates to the numerical difference between Newtonian and special AEXium relativistic Taylor equations.

One-way special relativistic and Newtonian radial Apemanium Taylor shifts may indicate that the military is testing a Taylor Hybrid generator prototype.


T
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« Reply #22 on: April 20, 2011, 12:15:58 PM »

Yaz wants to know if you are done with his silver poopium scoopium
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« Reply #23 on: April 20, 2011, 12:29:12 PM »

Bob, thanks for the explanation. I won't pretend that I understand it all, in fact you lost me at "phase encoding", but I'm glad someone out there knows what's going on! Watching the panadapter as the pulsed signal (aka 500 pound bumble bee) rolls by makes a fine visual display of a wave of energy traveling from lower frequencies to higher frequencies. My wife says it looks "pretty" and I try to never argue with her, so I agree that it does. I'm not sure what they are measuring or observing, but they sure are persistent about it!

Tom, that's an elegant description of the phenomenon. In fact, this sounds like the original grant proposal that was submitted to Congress for the 1.7 billion dollar project startup costs. Absolutely brilliant and equal in every way to the late Senator Ted Stevens explanation of the internet as a series of tubes:    

http://www.youtube.com/watch?v=6aFmib9NUoY&NR

I believe that 75 meters is actually a series of tubes, functioning in the ionosphere to pass along messages from one station to another. The Ionospheric Sounding project and the SIZZ-O-LEEN effect appear to be disrupting the series of tubes at times, and this cuts into Terry's high frequency response. Completely intolerable I say!
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« Reply #24 on: April 20, 2011, 12:45:19 PM »

Andersen Labs developed the dispersive delay line for converting a radar carrier pulse to a broadband signal. I think in RX the signal went back through the delay line in the reverse direction to compress the return. It may have been a pair of matched delay lines. This was long before digital DSP and Spread spectrum. The shape of the delay line determined the spread.
Most days I see a cluster of crud sitting on 3885 on th espectrum display just above the noise floor, never thought to DF it.
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