Strange wide signal sweeping across band upon startup or band change.

Bill-W9OL

Does anyone else see this strange signal. I see and hear this strange signal sweep across the band from low to high, very fast. When it passes the station I'm listening to, I hear it sweep past. When in cw, the signal looks narrow, maybe a kc wide. But in SSB mode it's at least 2.7 wide. It seems to happen most frequently a little after starting or going to any band. After listening to stations for a while, say 10 minutes, I no longer see this low to high frequency sweeping across the band. It sounds like the old days when someone left his rig keyed and changed frequency fast. It's always low freq to high end of the band. It could be something local, although I've never seen or heard it with my 5K, only this 6K. pse and thank you

Ed, K0KC

I have seen this same behavior...I do not think it is local.

Bill-W9OL

Thank you Ed As I don't hear or see it in my 5K, I was wondering if something was trying to 'lock' or 'find'. It's almost too fast and smooth to be someone swishing the dial. Probably NSA listening to us lowly DXers. :=)

Robert -- N5IKD

I have seen this too, I don't think it is local. Certainly people have seen this on other radios. It would be difficult to identify without a pan-adapter.

Dave-N9CHM

These are called "whistlers" and are thought to be mainly atmospherically generated. They almost always travel from low to high freqs. I've followed the same whistler from 75M up past 10M by expanding out/moving the panadapter as the signal moves up band. Lots of info on the net about them.

Keith - AE5XN

These are ionosonde stations that are used to find and map the MUF at multiple locations. For more info, see: http://www.arlut.utexas.edu/images/ionosondes_web.pdf http://www.ngdc.noaa.gov/stp/iono/ionogram.html http://www.ips.gov.au/IPSHosted/INAG/

Tom K3TF

Very interesting. I have seen the same thing with my K3 and P3 pan adapter. On my Icom 7700 it does not update fast enough to follow it. I see the same thing on my Flex 6700 here near Philly. Interesting info from Keith, thanks. I was wondering what that stuff is sweeping up the band.

Bill-W9OL

Well thanks to all as I wasn't worried that it was anything wrong with my rig. They were so wide and loud.

Ernest - W4EG

I often wonder what that signal was. Thanks

Ken - NM9P

As you look around the shortwave bands in between the ham bands, you can spot HF over the horizon radars scanning several tens of Khz at various frequencies, as well as spread spectrum stations jumping all over the bands. It is quite interesting to watch.

Bruce

Robert Cline Sure better than the old "woodpeckers" from the USSR. Over the horizon radars were used by the British early in WWII. Using 15 meter band they could pick up Luftwaffe aircraft taking off in France. I added a "Woodpecker Noise Filter developed by Yaesu on my FT-One. The USA OTH radars on both coasts and Alaska were sweep frequency similar to what I see now on my 6500. Thanks Kieth for the info. You tube has photos of the Woodpecker antennas. I have heard some JA's complain of a current Chinese OTH radar. Interesting stuff in our ether, what? Bruce N5FD

Bob G W1GLV

Very interesting, thanks for the info.

Ed, K0KC

I wonder why no one has mentioned seeing these signals on our Flex-3Ks or Flex-5Ks? Maybe some have but fail to question it or maybe the Flex-6K is just that much better!

Bob G W1GLV

I did see that on my 5K, but shrugged it off.

Bill-W9OL

That's what prompted my original question about the signals. With a 5K and 6K running, monitoring the same band segment, I would see/hear them on the 6K but nothing on the 5K. Someone replied that they sweep to fast for most receivers to hear hear/see them on the earlier radios.

Bob G W1GLV

As a matter of fact, I see it on my 1.5K.

Tim - W4TME

It is seen a lot easier on the 6000 because of the smaller FFT bin size which equates to a higher resolution display and the wider panadapter display.

Andrew VK5CV

It's just amazing what a high temporal resolution wide band receiver can detect. In the past some were just heard as they swished by. In PSDR the slower ones could be seen on the panadapter at higher refresh rates. Andrew